PEER INFLUENCE AND NON-SUICIDAL SELF-INJURY IN ADOLESCENCE:
EXPLORING THE ROLE OF CO-RUMINATION
by
SARAH M. LLOYD

A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF MASTER OF ARTS
in
THE FACULTY OF GRADUATE STUDIES
Master of Arts in Counselling Psychology

We accept this thesis as conforming to the required standard

…………………………………………
Joan S. Kimball, PhD., Thesis Supervisor

…………………………………………..
Derrick Klaassen, PhD., Thesis Supervisor

…………………………………………..
Jennifer Muehlenkamp, PhD., External Examiner

TRINITY WESTERN UNIVERSITY
February 2014
©Sarah M. Lloyd

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ABSTRACT
The main purpose of this study was to investigate the relationship between co-rumination
and non-suicidal self-injury (NSSI) in a community sample of adolescents. Analysis of
the data from 92 adolescent self-injurers, 51 female and 41 male, indicated that there was
a significant, positive correlation of small effect size between adolescents’ level of corumination and their frequency of self-injury in the past year. When genders were
examined separately, this positive correlation of small effect size remained significant
solely for male participants. Contrary to expectations, co-rumination failed to moderate
the relationship between depression and NSSI frequency, and stressful life events failed
to moderate the relationship between co-rumination and NSSI frequency. Results from
further post-hoc analyses and related research on peer socialization suggest possible
reasons for these results and future research avenues. The strengths, contributions, and
clinical implications of this study are also discussed.
Keywords: Non-suicidal self-injury; co-rumination; adolescents; depression;
stressful life events

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PREFACE
This research was approved by Trinity Western University’s Research Ethics Board (File No.
12G03) and was funded by the Social Sciences and Humanities Research Council for Canada
(Graduate Scholarship - Master's; Award No.: 766-2009-0280).

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TABLE OF CONTENTS
ABSTRACT ........................................................................................................................ ii
PREFACE .......................................................................................................................... iii
TABLE OF CONTENTS ................................................................................................... iv
LIST OF TABLES ............................................................................................................. ix
LIST OF FIGURES ........................................................................................................... xi
ACKNOWLEDGEMENTS .............................................................................................. xii
CHAPTER I: INTRODUCTION .........................................................................................1
Definition of Terms ..................................................................................................4
CHAPTER II: LITERATURE REVIEW ............................................................................5
Nonsuicidal Self-Injury ............................................................................................5
Prevalence of NSSI. .....................................................................................6
NSSI and distress. ......................................................................................10
Functions of NSSI. .....................................................................................11
Anti-suicide. ...................................................................................12
Self-punishment. ............................................................................12
Sensation-seeking. .........................................................................13
Interpersonal influence. ..................................................................13
Interpersonal boundaries. ...............................................................13
Anti-dissociation. ...........................................................................14
Affect regulation. ...........................................................................14

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Explanatory models of NSSI .....................................................................16
Experiential avoidance model. .......................................................16
Four function model. ......................................................................18
Emotional cascade model. .............................................................21
Co-Rumination .......................................................................................................25
What is co-rumination? ..............................................................................26
Co-Rumination, friendship quality, and affective distress .........................28
Co-rumination and NSSI in Adolescents ...............................................................34
Does co-rumination moderate the relationship between NSSI and
depression? .................................................................................................34
Is co-rumination directly linked with NSSI? .............................................36
The Current Study ..................................................................................................40
Research Design .....................................................................................................41
Single Time Point Survey Design. .............................................................41
Participants .............................................................................................................41
Sample Size ................................................................................................41
Inclusion and exclusion criteria .................................................................42
Characteristics ............................................................................................42
Procedure ...............................................................................................................43
Student recruitment, class presentations, and questionnaire administration.43

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Offers to school administration. .................................................................45
Measures ................................................................................................................45
Demographic information. .........................................................................46
Depression ..................................................................................................46
Co-rumination ............................................................................................47
Non-suicidal self-injury .............................................................................48
Peer NSSI ...................................................................................................49
Stressful life events ....................................................................................49
Screening of the Data .............................................................................................50
Reliability of Research Measures ..........................................................................52
CHAPTER IV: RESULTS .................................................................................................54
Descriptive Statistics ..............................................................................................54
Description of NSSI participants ...............................................................54
Analysis Results .....................................................................................................59
Correlation. ................................................................................................59
Hypothesis 1: Co-Rumination positively correlated with the
frequency of NSSI in adolescents. .................................................59
Hierarchical multiple regression ................................................................60
Hypothesis 2: Co-rumination moderates the relationship between
depression and the frequency of NSSI in adolescents. ..................60

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Hypothesis 3: Stressful life events moderates the relationship
between co-rumination and the frequency of NSSI in adolescents.62
Post-Hoc Analyses .................................................................................................65
Gender, age, and peer NSSI .......................................................................65
Gender differences. ........................................................................68
The impact of whether peers engage in self-injury on the relationship
between co-rumination and self-injury ......................................................73
CHAPTER V: DISCUSSION ............................................................................................75
Prevalence of NSSI ................................................................................................76
Characteristics of Self-Injuring Participants ..........................................................80
Co-Rumination and NSSI ......................................................................................82
Co-rumination positively correlated with NSSI in adolescents .................82
The relationship between co-rumination and self-injury in male
participants. ....................................................................................85
Co-rumination and stressful life events in male self-injurers. .......86
Co-rumination, peer self-injury, and adolescent self-injury ......................87
Co-rumination as moderator variable ........................................................88
Limitations .............................................................................................................91
Strengths and Contribution ....................................................................................95
Clinical Implications ..............................................................................................97
REFERENCES ................................................................................................................101

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Appendix A ..........................................................................................................124
Appendix B ..........................................................................................................125
Appendix C ..........................................................................................................128
Appendix D ..........................................................................................................129
Appendix E ..........................................................................................................130
Appendix F...........................................................................................................131
Appendix G ..........................................................................................................132
Appendix H ..........................................................................................................133
Appendix I ...........................................................................................................135
Appendix J ...........................................................................................................138
Appendix K ..........................................................................................................141
Appendix L ..........................................................................................................143

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LIST OF TABLES
Table 1: Cronbach’s Alpha for Research Measures for the all Participants and
Separately for Self-Injuring Participants............................................................53
Table 2: Demographic Variables of Participants who Engaged in NSSI in the Past Year55
Table 3: Range, Means and Standard Deviations for Measures by Gender in Self-Injuring
Participants (N = 92) ..........................................................................................57
Table 4: Correlations Between the Study Variables (N = 92) ...........................................58
Table 5: Hierarchical Regression Analysis for Gender, Depression, Co-Rumination, and
Depression X Co-Rumination Predicting Adolescent NSSI (N = 92) .................63
Table 6: Coefficients for Final Model in Hierarchical Multiple Regression Analysis for
Gender, Depression, Co-Rumination, and Depression X Co-Rumination
Predicting Adolescent NSSI (N = 92) .................................................................64
Table 7: Hierarchical Regression Analysis for Gender, Co-Rumination, Stressful Life
Events and Co-Rumination X Stressful Life Events Predicting Adolescent NSSI
(N = 92)...............................................................................................................66
Table 8: Coefficients for Final Model in Hierarchical Multiple Regression Analysis of
Gender, Co-Rumination, Stressful Life Events and Co-Rumination X Stressful
Life Events Predicting Adolescent NSSI (N = 92) ..............................................67
Table 9: Hierarchical Regression Analysis for Co-Rumination, Gender and CoRumination X Gender Predicting Interpersonal Independent Stressful Life
Events (N = 92) ...................................................................................................71

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Table 10: Coefficients for Final Model in Hierarchical Multiple Regression Analysis of
Co-Rumination, Gender and Co-Rumination X Gender Predicting Interpersonal
Independent Stressful Life Events (N = 92) ........................................................72

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LIST OF FIGURES
Figure 1. Simple slopes of co-rumination predicting interpersonal independent stressful
life events for males and females. .......................................................................70

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ACKNOWLEDGEMENTS
I would like to convey my deepest appreciation to my research supervisors Dr. Joan Kimball
and Dr. Derrick Klaassen whose encouragement throughout this process kept me motivated
and whose feedback made this thesis stronger. I am very thankful for your expertise and
dedication in working with me over a long distance! I would also like to thank my colleagues
at Child and Youth Mental Health in Fort St. John; without your unwavering belief that I
could complete this study and your support and encouragement throughout this process I am
not sure how I would have finished. I would also like to thank all the participants who
graciously took part in this study. Lastly, my deepest gratitude belongs to my family,
especially my husband Aaron, who always believed that I could do this and who also lived
through the ups and downs, and supported me, in this process.

1
CHAPTER I: INTRODUCTION
Clinicians, researchers, and the media alike are all too aware that non-suicidal
self-injury (NSSI), a pervasive and potentially dangerous group of behaviours, may be
increasing in prevalence, particularly among adolescents. Non-suicidal self-injury is
defined as “the deliberate direct destruction or alteration of body tissue without conscious
suicidal intent” (Favazza, 1998, p.260) and is not for religious or cultural purposes
(Heilbron & Prinstein, 2008). Whereas past research did not separate NSSI from suicidal
self-injury, the intent behind NSSI behaviour differentiates it from suicidal behaviours;
whereas “the suicidal person wants to eliminate consciousness permanently; the selfinjurer wants to modify consciousness, to reduce distress, in order to live another day”
(Walsh, 2006, p.8). While researchers now strive to distinguish between these two
behaviours, they may nevertheless co-exist, as research shows that adolescents who
engage in NSSI show elevated rates of suicidal ideation and attempts (Cuellar & Curry,
2007; Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006).
Additionally, it is important to note that while the social acceptability of NSSI is
expanding (Favazza, 2009), NSSI is not a culturally-sanctioned behaviour performed for
display, aesthetic purpose, or religious practice (Nixon & Heath, 2009). In fact, there is
great concern regarding the large proportion of adolescents in the community who engage
in NSSI and that this behaviour has also been reported to have a contagion effect among
adolescents who believe it to be a helpful coping strategy (Derouin & Bravender, 2004;
Hodgson, 2004). Adding to this concern is the emerging developmental research which
has started to illustrate how internet discussion forums about NSSI (i.e., methods,
associated feelings) have increased in popularity and are most likely occupied by

2
adolescents (Whitlock, Powers, & Eckenrode, 2006). These findings, along with the
significant association between NSSI and affective distress (i.e., NSSI is used to diminish
affective distress and is associated with symptoms of depression and anxiety; e.g.,
Klonsky, Oltmans, & Turkheimer, 2003), are concerning and highlight the need to further
study adolescent NSSI in the community.
In the past, research on NSSI focused on clinical populations, specifically within
the context of borderline personality disorder (BPD; Favazza, 1998). However, while the
prevalence of NSSI in clinical samples is high, focus has started to shift as evidence has
shown NSSI to be more common among community samples. In particular, an
alarmingly high lifetime prevalence rate of 15-20% has been reported in community
samples of adolescents (Heath, Schaub, Holly, & Nixon, 2009). Research specifically
examining NSSI in adolescents continues to grow, whereas past research used to merge
results from adolescent and adult studies into discussions of NSSI (Lofthouse,
Muehlenkamp, & Adler, 2009). Yet, adolescence is a period with distinct developmental
and environmental differences that offer a unique context within which to study the onset,
maintenance, and potential transmission of NSSI behaviour (Whitlock & Knox, 2009).
Of particularly significant impact during adolescence are peer relationships.
Considering their importance in adolescent socioemotional development (e.g., Bukowski,
Newcomb, & Hartup, 1996), it is essential to investigate social processes which may
influence the frequency and prevalence of NSSI. One process of particular interest is corumination, which is defined as “excessively discussing personal problems within a
dyadic relationship” (Rose, 2002). While supportive adolescent friendships have
traditionally been viewed as protective against affective distress (Bukowski et al., 1996),

3
the tendency to co-ruminate may in fact be maladaptive and increase risk for the
development of affective distress.
The relationship between co-rumination and NSSI has not yet been investigated
and thus, will be the main purpose of this study. Specifically, this study will explore the
possibilities that corumination is either directly linked to the frequency of NSSI in
adolescents or moderates the association between affective distress (i.e., depression) and
NSSI. This study will also examine whether the number of stressful events moderates the
proposed direct relationship between NSSI and co-rumination. The dependent variable in
this study is adolescent NSSI and the three independent variables are depression, corumination, and stressful life events.
This study is expected to further expand upon the burgeoning research on NSSI in
adolescents in the community. While research has started to show the importance of
adolescents’ interpersonal experiences as relevant for understanding and treating NSSI
(Prinstein, Guerry, Browne, & Rancourt, 2009), this study seeks to provide empirical
evidence to further support and expand on this area of research, specifically regarding the
unique role of co-rumination. The association between these two constructs has not yet
been investigated and offers promising insight into the significance of peer influence
effects in adolescent NSSI; any findings can be used to guide treatment and aide
clinicians in their understanding of NSSI behaviours. Indeed, determining the
relationship between co-rumination and NSSI in adolescents will further elucidate how
peers influence NSSI behaviour in adolescents and will aid in the design of interventions
that maximize the emotional health of adolescents who self-injure.

4
Definition of Terms
As previously noted in this introduction, for the purposes of this study NSSI is
defined as “the deliberate direct destruction or alteration of body tissue without conscious
suicidal intent” (Favazza, 1998, p.260). In addition, co-rumination is defined as
“excessively discussing personal problems within a dyadic relationship” (Rose, 2002).
While affect, emotion, and mood are used in different ways by different
researchers, for the purpose of this study the term affect is predominately used. Larson
(2000) defines affect as the “felt aspect of mood and emotion…[and] thus the feeling tone
associated with mood and emotion, and it is primarily evaluative. Affect is felt as good
or bad, as pleasant or unpleasant, as a felt tendency to approach or to avoid” (p. 129).
This definition parallels that given by Klonsky and Wienberg (2009) in their chapter on
the assessment of NSSI; that affect “refers to the emotions or feelings one might have
before, during, or after NSSI. Understanding these feelings is vital for understanding
one’s motivations for NSSI” (p.185; Klonsky & Wienberg, 2009).

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CHAPTER II: LITERATURE REVIEW
Nonsuicidal Self-Injury
Nonsuicidal self-injury is a complex and multidimensional construct with a clear
and pervasive presence in community settings (Heath et al., 2009). With NSSI becoming
part of our social landscape (Favazza, 2009), identifying variables that may contribute to
the onset or maintenance of this behaviour should prove useful in case conceptualization
and in developing effective intervention and prevention approaches. Peer relationships
are a particularly salient domain of influence during adolescence, and often are a
significant source of social support (Furman & Buhrmester, 1992). Research examining
the impact of social processes on adolescent NSSI has started to proliferate. This study
seeks to expand upon this promising area of research by examining co-rumination, a
potentially maladaptive form of peer social interaction that has been linked to an
increased risk for the development of affective distress (e.g., Rose, 2002; Rose et al.,
2007; Stone, Hankin, Gibb, and Abela, 2011), and its possible contribution to NSSI in
adolescents.
In order to understand how co-rumination may contribute to NSSI behaviour in
adolescents a review of both NSSI and co-rumination research will be completed. A
general discussion of NSSI prevalence and its association with affective distress will be
followed by a review of its many functions, with particular emphasis on its affect
regulating function which has particular relevance for this study. Following this, three
models which include the affect regulating function and attempt to provide clinically
useful conceptualizations of NSSI will be reviewed. Specifically, the emotional cascade
model (ECM; Selby, Anestis, & Joiner, 2008; Selby & Joiner, 2009) is a promising

6
theoretical framework that has recently been proposed as helpful in understanding NSSI
in individuals (Selby, Connell and Joiner, 2010). The ECM not only clarifies why
individuals may engage in NSSI but also proposes a pathway for how NSSI works to
regulate affect. Importantly, the ECM will not be tested in this study, but will be used to
support a possible link between co-rumination and NSSI in adolescents.
Following a review of NSSI, a review of co-rumination and the research that
supports its role in increasing affective distress and its possible connection to NSSI
behaviour in adolescents will be conducted. After reviewing research supporting the role
of corumination in increasing affective distress in adolescents, this review will explore
the possibilities that corumination is either directly linked to the frequency of NSSI or
moderates the association between distress (i.e., depression) and NSSI. Lastly, the
possible impact of stressful life events, gender, age, and peer NSSI behaviour on the
proposed relationships between adolescent NSSI and co-rumination will also be
discussed.
Prevalence of NSSI. When perusing the literature regarding the prevalence of
NSSI the significant variability in rates reported can be confusing. Essentially, due to the
study of NSSI being relatively new, there has been little consistency concerning
methodology in the study of self-injury. In critically reviewing the literature, it is
important to take into account the variations in methodology concerning measurement,
sample selection (i.e., community vs. clinical) and sample composition (i.e., gender, race,
and sexual orientation), and how NSSI is defined (Nixon & Heath, 2009).
A critical distinction when evaluating prevalence is whether participants were
taken from community or clinical settings. Clinical settings have higher prevalence rates

7
while community settings offer much more variability (i.e., schools vs. general
population; urban vs. rural). For adolescents in the community, lifetime prevalence rates
average around 15-20% (Heath et al., 2009). Results that have markedly higher
prevalence rates (e.g., Gratz, 2006; Gratz, Conrad, & Roemer, 2002; Hilt, Cha, NolenHoeksema, 2008; Lloyd, 1997; Lloyd-Richardson, Perrine, Dierker, & Kelley, 2007)
likely diverged due to the use of checklists which included all possible self-injurious
behaviours. In providing a list of many possible types of self-injury resulting in tissue
damage (e.g., biting; sticking needles in skin; scraping skin) researchers have to rely on
participants understanding of the construct of NSSI, and participants may endorse every
behaviour they have engaged in whether for NSSI purposes or not. Understandably,
researchers (Heath et al., 2009) are calling for follow-up interviews to assist in clarifying
participants’ understanding of whether the tissue damage was indeed NSSI or due to
other behaviours (e.g., drug use). After follow-up interviews, the rate of NSSI in Ross
and Heath (2002) was substantially reduced from 21.2% to 13.9%. In addition, some
researchers ask for “lifetime” prevalence (e.g., Kumar, Pepe, & Steer, 2004; Ross &
Heath, 2002), while others limit prevalence to the past year (e.g., Nock & Prinstein,
2004). This highlights how variation in measurement of NSSI affects prevalence ratings.
The setting in which we gather our participants will also influence the gender
distribution we are likely to see among self-injurers. While significant gender differences
are expected in clinical settings, it remains unclear whether significant gender differences
in NSSI prevalence will be found in community samples. Certain community based
studies have found significant gender differences (Evans, Hawton, Rodham, & Deeks,
2005; Hawton, Rodham, Evans, Weatherall, 2002; Muehlenkamp & Gutierrez, 2007;

8
Ross & Heath, 2002), while others have found no significant gender differences in NSSI
prevalence (e.g., Jacobsen, Muehlenkamp, Miller, & Turner, 2008; Nixon, Cloutier, &
Aggarwal, 2002). In clinical samples, females predominately engage in higher rates of
NSSI. This difference is attributed to females being more prone to seek help than males
and due to the inclusion of predominately female behaviours as NSSI (i.e., overdose and
medication abuse without suicidal intent; Briere & Gil, 1998; Rodham, Hawton, &
Evans, 2004). Indeed, studies within the community which have found gender
differences (Laye-Gindhu & Schonert-Reichl, 2005; Nixon, Cloutier, & Jansson, 2008;
Patton et al., 1997) have included overdose and medication abuse without suicidal intent,
while community studies that limited their NSSI to forms of tissue damage such as
cutting, burning, or self hitting failed to find a gender difference (Lloyd-Richardson et al.,
2007; Muehlenkamp & Gutierrez, 2004, 2007; Izutsu et al., 2006; Zoroglu et al., 2003).
While research suggests that NSSI is more prevalent among females, in both clinical and
community settings (Nock, 2009); females are more likely to cut themselves and injure
their wrists or thighs, while males more likely to self-hit, bang, or burn and injure their
hands (Claes, Vandereycken, & Vertommen, 2005; Heath, Toste, Nedecheva, &
Charlebois, 2008; Holly, Heath, Toste, & Schaub, 2007; Izutsu et al., 2006; Laye-Gindhu
& Schonert-Reichl, 2005; Whitlock, Eckenrode, & Silverman, 2006). Thus, gender
appears to partially predict who is likely to engage in NSSI, and is also associated with
the location of and type of self-injury utilized.
Additionally, ethnicity and sexual orientation have been found to influence
prevalence rates. Community based studies show that NSSI may be more common in
Caucasian, than in African-American and African-Canadian, adolescents (Lloyd-

9
Richardson et al., 2007; Muehlenkamp & Gutierrez, 2004, 2007; Ross & Heath, 2002;
Whitlock, Eckenrode, et al., 2006). The prevalence of NSSI in Aboriginal adolescents in
Canada is unknown, but an international literature review (Evans et al., 2005) suggests
that among American adolescents the prevalence of self-injury is higher in Native
American adolescents than in Black or White adolescents. Caution is required in
generalizing this finding though, since self-injury with suicidal intent was included in this
review. Furthermore, preliminary findings with young adults in the community indicate
that NSSI may occur more frequently in individuals who are gay, lesbian, or conflicted
about their sexual orientation (e.g., Gratz, 2006; Whitlock, Eckenrode, et al., 2006).
While cultural awareness of NSSI has increased, and the media, researchers, and
clinicians alike claim that the prevalence of NSSI is increasing in adolescents (e.g.,
Derouin & Bravender, 2004; Plener & Muehlenkamp, 2007; Walsh, 2006; White Kress,
2003), empirical evidence to endorse this assertion is lacking thus far. As pointed out by
Heath et al. (2009), support for the claim that self-injury is increasing has arisen from
trend studies in the United Kingdom on “self-harm”, which utilizes an extensive
definition which includes all nonfatal self-inflicted harm (e.g., suicide attempts; e.g.,
Hawton et al., 2003; Olfson, Gameroff, Marcus, Greenberg, & Shaffer, 2005).
Furthermore, Heath et al., (2009) point out that it would also be difficult to evaluate
literature on NSSI from the last 15 years because “in clinical settings, this behaviour was
often subsumed under personality disorders and not reported separately” (p.23).
Furthermore, it may be that the reporting and identification of self-injury has been
influenced by increased media coverage over the past 15 years and increased help seeking
for self-injuring behaviours by youth (Whitlock, Ells, Cummings, & Purington, 2008).

10
The assertion that NSSI, as defined for the current study – “the deliberate direct
destruction or alteration of body tissue without conscious suicidal intent” (Favazza, 1998,
p.260) – is increasing cannot be made at this time. Yet, researchers agree that NSSI is a
pervasive and potentially dangerous group of behaviours and adolescence appears to be a
period of increased risk for NSSI. The majority of adolescents first engage in self-injury
between the ages of 13 and 15 (e.g., Muehlenkamp & Gutierrez, 2007; Ross & Heath,
2002; Sourander et al., 2006), though studies have shown that a considerable amount
begin earlier. For example, in Ross and Heath’s (2002) study, 59% of their high school
student sample indicated they first engaged in self-injury at age 12, while 24% were age
11 or younger.
NSSI and distress. Besides finding an increase in the proportion of youth who
engage in NSSI throughout early and mid adolescence, it has also been suggested that
individuals who engage in NSSI are at increased risk of later dying by suicide (Joiner,
2005). In fact, individuals who engage in NSSI consistently report elevated rates of
suicidal ideation and attempts (Cueller & Curry, 2007; Nock et al., 2006). Moreover, 30
and 15-fold increases in risk for suicide have been found, respectively by Cooper et al.
(2005) and Sakinofsky (2005), for those who engage in NSSI compared with those who
do not.
In addition, the majority of adolescents who self-injure have also been found to
meet criteria for current mental and personality disorders (Nock et al., 2006). In fact,
various psychiatric conditions appear to confer heightened risk for the development of
NSSI (Klonsky & Glenn, 2009). Clinical samples of adolescents who have engaged in
NSSI have shown elevated rates of major depressive disorder (MDD), externalizing

11
disorders, substance use, and borderline personality disorder (BPD) when compared with
those who do not self-injure (Jacobsen et al., 2008; Kumar et al., 2004; Nock, Joiner,
Gordon, Lloyd-Richardson, & Prinstein, 2006). Only one community-based study
(Garrison, Addy, McKeown, & Cuffe, 1993) formally assessed both NSSI and
psychiatric disorders; the researchers found that diagnoses of MDD, specific phobia,
obsessive-compulsive disorder, or a combination of these was associated with an elevated
risk of engaging in NSSI. In other community based studies with adolescents, without
formal assessment of psychiatric disorders, NSSI was most frequently associated with
suicidal behaviour followed by depression and substance use, hostility and anger, and
then anxiety (Laye-Gindhu & Schoner-Reichl, 2005; Lloyd-Richardson et al., 2007;
Muehlenkamp & Gutierrez, 2004, 2007; Ross & Heath, 2002). Eating disorder features
have also been found to be significantly more common in adolescent self-injurers than
non-injurers (Ross, Heath, & Toste, 2009).
Of particular relevance for this study, NSSI has been found to be associated with
symptoms of depression and anxiety (Andover, Pepper, Ryabchenko, Orrico, & Gibb,
2005; Hawton et al., 2002; Nixon et al., 2002; Nock et al., 2006; Klonsky et al., 2003;
Ross & Heath, 2002). This association may be due to the possible presence of emotion
dysregulation in both of these disorders (Gross & Munoz, 2005; Mennin, Heimberg,
Turk, & Fresco, 2005). In order to understand the association between affective distress
and engaging in NSSI, it is imperative to review the functions of NSSI.
Functions of NSSI. When considering the literature on the functions of NSSI, it
is important to consider that NSSI is contextually complex. Essentially, individuals are
tied to their environment and as Suyemoto (1998) states in her review of functional

12
models of NSSI, “one of the most difficult tasks in attempting to understand any
pathological behavior is discerning why this particular behavior, at this particular time,
serves this particular function, for this particular patient” (p.537). Thus, the reasons an
individual engages in NSSI may vary over time and context. Additionally, NSSI is likely
overdetermined; it may fulfill multiple functions simultaneously. While the following
review presents the functions separately, they may occur at the same time and be
conceptually related (Klonsky, 2007).
Examining the literature on the functions of NSSI can be a challenging process,
with researchers utilizing different definitions for the same function. Klonsky (2007) has
identified seven functions that have been researched most consistently, labeling and
providing descriptions for each. The seven functions are labeled as anti-suicide, selfpunishment, sensation-seeking, interpersonal boundaries, interpersonal influence, antidissociation, and affect-regulation. While all will be reviewed, emphasis and further
elaboration will be made for the affect-regulation function which has particular relevance
for this study.
Anti-suicide. The anti-suicide function depicts NSSI as a maladaptive coping
mechanism that aids an individual in preventing or avoiding suicidal thoughts or
behaviours (Klonsky, 2007). In the anti-suicide function, NSSI is a “morbid form of selfhelp” (Favazza, 1998) where an individual makes a compromise and replaces suicidal
behaviour with NSSI (Suyemoto, 1998) in order to ease his/her distress instead of ending
his/her life.
Self-punishment. Another function with partial support (Klonsky, 2007) is the
self-punishment function (Briere & Gil, 1998; Himber, 1994; Klonsky et al., 2003). This

13
function suggests that NSSI is used to articulate self-hatred and self-directed anger, wellknown characteristics of self-injurers (Herpertz, Sass, & Favazza, 1997; Klonsky et al.,
2003). Specifically, NSSI appears to be used to punish or invalidate oneself. Linehan
(1993) hypothesizes that this need to punish and invalidate oneself was modeled after
experiences in an early invalidating environment.
Sensation-seeking. The sensation-seeking function considers NSSI as a
collection of behaviours that trigger exhilaration and excitement for the individual (Nixon
et al., 2002; Osuch, Noll, & Putnam, 1999; Shearer, 1994). This rush of excitement is
reported to be similar to that felt when sky-diving or bungee jumping. This function is
not readily evident in clinical populations which may explain the scarcity of literature
examining this model (Klonsky, 2007).
Interpersonal influence. The interpersonal influence function depicts NSSI as a
means of communication and/or expression or way to provoke a response from others in
the self-injurer’s environment (Briere & Gil, 1998; Chowanec, Josephson, Coleman, &
Davis, 1991; Himber, 1994). In this sense, self-injury is hypothesized to be a means by
which an individual expresses their desire for help, to prevent others from abandoning
them, or to convince others to take them more seriously (Allen, 1995). Once others
respond to the self-injuring behavior this form of communication is reinforced.
Interpersonal boundaries. Klonsky (2007) described how the interpersonal
boundaries function depicts individuals who engage in NSSI as striving to affirm their
autonomy or establish a sense of self (Carroll, Schaffer, Spensley, & Abramowitz, 1980;
Suyemoto, 1998). Klonsky speculates that those who use NSSI for this function
experienced insecure attachments and poor individuation from their primary caregivers,

14
and therefore view NSSI as a means of establishing these missing boundaries. It may be
that “intense emotional reactions to perceived abandonment threaten the boundaries of
the ‘‘self,’’ and [NSSI] functions to re-affirm or strengthen these boundaries” (p. 374;
Chapman, Gratz, & Brown, 2006).
Anti-dissociation. Additionally, Klonsky (2007) described the anti-dissociation
function of NSSI which depicts self-injury as an attempt to stop periods of dissociation
(Briere & Gil, 1998) or depersonalization; to stop feeling nothing or unreal. Alternately,
experiences of dissociation or depersonalization may be the result of the intense affect
present during self-injury (Klonsky). It is suggested that the act of NSSI, with the
associated sight of blood (Simpson, 1975) or the physical sensation (Gunderson, 1984),
shocks the system and disrupts episodes of dissociation allowing the individual to recover
a sense of self (i.e., to feel real and alive again).
Affect regulation. NSSI is most frequently conceptualized as an affect regulation
mechanism. Klonsky’s (2007) comprehensive review of research on NSSI motivations
found strong evidence that episodes of overwhelming or intense negative affect or
affective arousal precede NSSI, diminished negative affect and feelings of relief and calm
occur after NSSI, and self-injury proxies (e.g., visualizing self-injury or completing a
painful task) also result in reduced negative affect in laboratory settings (see Brain,
Haines, & Williams, 1998).
Studies have shown that individuals who self-injure report greater subjective
levels of experienced affective distress when faced with stressful events (Najmi, Wegner,
& Nock, 2007; Nock, Wedig, Holmberg, & Hooley, 2008). In fact, “a key assumption of
the affect regulation model is that self-injurers are less able (or less willing) to tolerate

15
intense distress than non-injurers, regardless of whether the experience of greater
reactivity is subjective or physiologically based, and that they use NSSI as a means of
escaping from the experience of intense distress” (Nock & Mendes, 2008, p.29). This
inability to tolerate distress is believed to be an essential facet in the development and
maintenance of self-injury (Chapman, et al., 2006; Favazza, 1996; Klonsky, 2007).
Indeed, the most common reason individuals give for engaging in NSSI is to alleviate, or
escape from, overwhelming affective distress (Brown, Comtois, & Linehan, 2002;
Chapman et al., 2006; Favazza, 1992; Gratz, 2003; Haines, Williams, Brain, & Wilson,
1995; Klonsky, 2007; Nock & Prinstein, 2004, 2005). Specifically, affect regulation (“to
cope with feelings of depression”; “to release unbearable tension”) was the most
frequently endorsed reason for NSSI among hospitalized adolescent self-injurers (Nixon,
Cloutier, & Aggarwal, 2002). Evidence indicates that as a result of self-injurers’ inability
to deal with overwhelming affective states, such as feelings of anger, anxiety, frustration,
depression, tension, loneliness, or emptiness, NSSI is carried out in order to achieve the
goal of diminishing affective distress (Austin & Kortum, 2004; Briere & Gil, 1998;
Gratz, 2003; Haines et al., 1995; Himber, 1994). Paralleling these findings, there is also
evidence that NSSI is less prevalent in individuals who experience negative affect less
intensely and less often, though individuals who experience positive affect more intensely
and more often do not appear to have lower risk (Klonsky et al., 2003).
Recent research (Gratz et al., 2011) further clarifies the relationships between
NSSI and the willingness to experience emotional distress and tolerate physical pain.
These researchers found that following interpersonal stressors, women who engage in
self-injury are less willing to tolerate emotional distress and show a greater tolerance for

16
physical pain. Gratz and colleagues propose that when self-injurers’ ability to selfregulate is depleted in the face of a stressor they turn to NSSI since they are more willing
to tolerate physical pain than emotional distress.
One recent study (Muehlenkamp et al., 2009) expanded upon current
understanding of the emotional consequences of NSSI by looking at real-time data of
both positive and negative affect states before and after acts of NSSI. This study found
that NSSI serves as a real-time affect regulating mechanism in individuals with bulimia
nervosa. Negative affect increased and positive affect decreased prior to individuals
engaging in NSSI, while positive affect increased following NSSI, supporting previous
findings that NSSI is used to manage affective distress (Laye-Gindhu & Schonert-Reichl,
2005; Nock & Prinstein, 2004).
Explanatory models of NSSI. While NSSI likely has multiple determinants
(Suyemoto, 1998) and many individual functions have been proposed, the following
models attempt to provide clinically useful conceptualizations of NSSI by either
cohesively integrating functions, or elaborating on how NSSI fulfills these functions.
Following is a review of three models which have attempted to further our understanding
of why an individual may want to self-injure. The following models will not be tested in
this study, but provide a theoretical basis to support the hypotheses of this study.
Experiential avoidance model. Chapman et al.’s (2006) experiential avoidance
model (EAM) of NSSI shows how the leading three functions (e.g., affect regulation,
anti-dissociation, and interpersonal boundaries; Klonsky, 2007) are all joined by the
notion that NSSI helps the individual to control their affect. Specifically, when an
individual experiences emotion dysregulation and negative affect they engage in NSSI as

17
a way of escaping, or avoiding, the negative affect they are experiencing. For instance,
while the affect regulation function of NSSI directly allows an individual to control
overwhelming affect, the anti-dissociation function suggests that NSSI regulates affect
through an interaction with dissociative behavior to terminate an aversive dissociative
state. Additionally, the interpersonal boundaries function suggests that when intense
affective distress occurs due to an individual’s boundaries of the “self” being threatened;
NSSI is used to reaffirm or strengthen a sense of self.
Essentially, experiential avoidance includes behaviors that allow an individual to
either avoid, or escape from, distressing internal experiences (i.e., thoughts, feelings,
somatic sensations) or the external experiences that trigger them (Hayes, Wilson, Gifford,
Follette, & Strosahl, 1996). Importantly, while Chapman et al. (2006) propose that NSSI
is utilized primarily to avoid unwanted affect, it also may aid in avoiding other distressing
internal experiences (i.e., thoughts, memories, somatic sensations) due to their linkage
with the unwanted affect. According to the EAM, NSSI “is maintained and strengthened
through the process of escape conditioning and powerful negative reinforcement” (p.374;
Chapman et al., 2006). Basically, when a distressing level of affective arousal is
triggered by an internal or external emotionally distressing experience an individual
engages in NSSI in order to escape the overwhelming state of arousal. NSSI is thus
negatively reinforced when it successfully diminishes or terminates the emotional
arousal. Over time, through repeated negative reinforcement, NSSI may become an
automatic avoidance behaviour associated with eliminating unpleasant affective states.
This behavioral theory of NSSI was developed to apply to NSSI across various
populations, rather than focusing solely on certain clinical populations (e.g., BPD; see

18
Linehan, 1993). The authors claim the EAM integrates various pieces of the puzzle of
NSSI, with supportive psychophysiological studies showing that NSSI reduces
physiological and affective arousal (Brain et al., 1998; Haines et al., 1995), and research
showing the single most common reason for engaging in NSSI being to obtain affective
relief or to regulate affect (Brown et al., 2002). Furthermore, Chapman et al., (2006)
provide three possible mechanisms (i.e., the opioid, distraction, and self-punishment
hypotheses; see Chapman et al., 2006), along with supportive research, which underlie
the EAM to explain why individuals who engage in NSSI experience affective relief.
Although this proposed theoretical framework is promising, and contributes to the
understanding of why an adolescent may engage in NSSI, evaluation of the EAM in
adolescents and the pathways through which it facilitates the avoidance or escape of
emotional experience is needed. This further evaluation may help clarify why other
behaviors (e.g., taking a cold shower, listening to music) are not used instead of NSSI,
and why adolescents do not engage in NSSI every time they wish to avoid the negative
affect they experience when faced with a distressing event.
Four function model. Lloyd-Richardson, Nock, and Prinstein (2009) view the
research evaluating functions of NSSI as being limited. Specifically, NSSI functions
have not been sufficiently evaluated in adolescent populations and the EAM model solely
emphasizes the negatively reinforced properties of NSSI while ignoring the other possible
functions of NSSI. Furthermore, they find that the term function has been used too
loosely and should be used solely to specify those which fit the traditional functional
analyses definition, of learning theory and behaviour therapy, which refers to the
examination of the antecedents and consequences of the NSSI behaviour with the purpose

19
of understanding and treating it. Accordingly, Nock and Prinstein (2004, 2005) have
“recently proposed and evaluated a comprehensive, four-function model of NSSI among
adolescents that is consistent with and draws from prior work on learning theory and
behavior therapy” (p.33; Lloyd-Richardson et al., 2009).
The four functional model (FFM; Nock & Prinstein, 2004, 2005) conceptualizes
NSSI as having both automatic (i.e., emotion-regulation) and social (i.e., interpersonal)
functions; the automatic functions regulate internal experiences, while the social
functions regulate the external environment. An orthogonal dimension of the model
suggests that NSSI can be maintained by either positive or negative reinforcement. These
two dimensions result in four types of NSSI functions; engaging in NSSI for (a)
automatic negative reinforcement (ANR; e.g., “To stop bad feelings”), (b) automatic
positive reinforcement (APR; e.g., “To feel something, even if it is pain”), (c) social
negative reinforcement (SNR; e.g., “To avoid doing something unpleasant you do not
want to do”), and (d) social positive reinforcement (SPR; e.g., “To get attention”). In
addition, individuals may engage in self-injury behaviors for multiple functions; the four
types of functions are not mutually exclusive (Nock & Prinstein, 2004, 2005; Nock &
Cha, 2009).
Evidence supporting the FFM has been found through self-report, physiological,
and behavioural research in adolescent populations. Self-report research in adolescent
clinical (Nock & Prinstein, 2004, 2005) and community (Lloyd-Richardson et al., 2007)
samples supports the structure of the FFM and helps explain the wide range of correlates
associated with NSSI by linking them with specific FFM functions. For example,
individuals who have endorsed the ANR function of NSSI, report greater levels of

20
affective states from which they want to escape (i.e., emotion reactivity, hopelessness)
and methods of escape from intolerable cognitive and affective states (i.e., thought
suppression and suicide). The APR function, where an individual engages in NSSI to
“feel something”, has been strongly linked with the clinical correlates of anhedonia,
inactivity, and numbness (Nock & Prinstein, 2005; Weierich & Nock, 2008).
Researchers have also correlated social concerns with the endorsement of social functions
of NSSI (Nock & Prinstein, 2005). Moderating factors have also started to be elucidated;
peer communication and rumination have been identified as moderators between social
functions (i.e., SNR and SPR) and interpersonal distress and between APR and internal
distress, respectively (Hilt, Cha et al., 2008).
Complementing earlier findings, that those who engage in NSSI display decreased
arousal when imagining engaging in NSSI (Haines et al., 1995), Nock and Mendes
(2008) found that adolescents with recent histories of NSSI had greater physiological
arousal (i.e., skin conductance) in response to, and poorer ability to tolerate, a stressor
than individuals without a history of NSSI. This effect was found to be strongest for selfinjurers who endorsed the ANR function of NSSI, as would be expected considering their
need to escape the experience of increasingly distressing arousal. In the same study,
Nock and Mendes evaluated a behavioural aspect of NSSI. Specifically, they looked at
the social problem solving skills of those who self-injure and found that there were no
deficits in the quantity or quality of solutions generated. Rather, self-injurers were more
likely to choose maladaptive solutions or report lower self-efficacy for applying adaptive
solutions when it came time to select specific solutions for socially challenging situations.

21
While the FFM has gathered empirical support for its structure, and provides for a
new understanding of NSSI in adolescents, it does not address how NSSI is used to
resolve affective distress or communicate with others. Further elaboration is needed to
explain how NSSI fulfills these four functions and clarify the questions also raised by the
EAM (i.e., why is NSSI chosen over other behaviours to cope and why is it not used all
the time for the proposed functions?)
Emotional cascade model. The Emotional Cascade Model (ECM; Selby et al.,
2008; Selby & Joiner, 2009) is a recent theoretical model that proposes the relationship
between affective and behavioral dysregulation in individuals with borderline personality
disorder (BPD) may be explained by rumination, the cognitive process that involves
repetitive focus of attention on one’s thoughts and emotions (Nolen-Hoeksema and
Morrow, 1991). Selby et al. (2010) have also recently proposed that this theory is helpful
for understanding NSSI in individuals without BPD. It may be that a process like an
emotional cascade, as described by Selby et al. (2008) and Selby and Joiner (2009), may
occur and trigger NSSI. The emotional cascade model suggests that once an individual
starts to ruminate about an affect eliciting event they experience heightened negative
affect. As the intensity of the negative affect increases, the individual finds it
increasingly difficult to divert attention away from the emotional event, and rumination
about the event increases. Essentially, rumination and negative affect interact in a
positive feedback loop; this ever intensifying loop drives the individual to engage in
other, more compelling ways, of distracting themselves, like NSSI, to break free from the
cascade and experience affective relief (Selby, Anestis, Bender, Joiner, 2009).

22
The role of rumination in the ECM is vital; it alludes to who is capable of selfinjury and why they may do so. Rumination amplifies and prolongs negative affect
(Moberly and Watkins, 2008; Thomsen, 2006), whether it is sadness, anger, or fear, and
thus predicts why individuals engage in NSSI (Selby et al., 2010). Essentially,
rumination may account for low distress tolerance; explaining why minute negative
emotional stimuli result in an extreme affective response, heightened emotional intensity
and slow return to baseline in self-injurers. As a result, events that appear insignificant to
others may trigger an intense self-perpetuating cycle that is resistant to mild distractions
(e.g., talking to a friend, taking a shower) or other cognitive strategies (e.g., cognitive
reappraisal). Thus, a self-injurer uses a dysregulated behavior (i.e., cutting arm) strong
enough to shift the focus of their attention to the sensations (i.e., pain or sight of blood)
associated with it, breaking the cascade and allowing negative affect to subside. Due to
the intense physical sensations of NSSI behaviours they may be particularly salient
distractions from rumination (Selby et al., 2009).
Additionally, opponent processes may work so that an individual will habituate to
the pain of NSSI and alternatively experience feelings of relief (Joiner, 2005); an
individual will recognize that NSSI regulates their affect. These effects may be
temporary, however, and any resulting feelings of shame or embarrassment may trigger
another cascade. The ECM also clarifies why self-injurers do not use NSSI every time
they feel negative affect (Selby & Joiner, 2009); if an individual does not ruminate, the
negative feelings are likely to fade without requiring self-injury. For example, if a youth
who regularly engages in self-injury feels anger after a hurtful social interaction, but is
prevented from ruminating due to a strong distraction (e.g., taking part in a sporting event

23
or demands of an academic project at school), the youth may not feel compelled to
engage in NSSI to feel relief if his/her anger has already diminished due to inattention.
While evidence supporting the ECM is relatively nascent (see Selby et al., 2009
and Selby & Joiner, 2009), NSSI is well-established as having an affect regulation
function and has also been tied to rumination in adolescents without BPD (Hilt, Cha et
al., 2008) and in adults with (Brown et al., 2002; Selby et al., 2009) and without BPD
(Armey & Crowther, 2008; Borrill, Fox, Flynn, & Roger, 2009; Selby et al., 2010). A
few of these recent studies have examined the role of rumination in maintaining NSSI
directly. Borrill et al. (2009) examined coping style, rumination, and alexithymia, with
617 undergraduate students in the UK and found that those who engaged in each type of
self-injury had higher levels of self-reported rumination, and rumination significantly
predicted self-injury status. It should be noted though that this study included overdose
as a form of self-injury which does not fit with the current study’s definition of NSSI.
Prior to this, Armey and Crowther (2008) gathered self-report data on aversive selfawareness (which included rumination), dissociation and NSSI from 225 undergraduate
students in the US. Upon evaluating the results of their study, they proposed that
rumination intensifies negative affect in self-injurers through contributing to aversive
self-awareness. This suggests that the self-critical focus of rumination, rather than a
constructive reflection on a problem, is what contributes to increasing negative affect.
Most recently, Selby et al. (2010) examined the interaction between rumination and
painful life events in predicting NSSI in 94 undergraduate students. Self-report data
indicated that there was an interaction effect of painful events and rumination on the

24
frequency of NSSI. Higher levels of rumination combined with a greater number of
painful events predicted a higher frequency of NSSI.
Lastly, the sole study with adolescents as participants (Hilt, Cha et al., 2008)
utilized the FFM to examine self-report data to determine whether rumination moderated
the relationship between depressive symptoms and the use of NSSI for affect regulation.
It was determined that while rumination moderated the relationship between depression
and engaging in NSSI for APR (i.e., to feel something rather than dissociating) it did not
moderate the relationship between depression and engaging in NSSI for ANR (i.e., to
stop bad feelings). This finding challenges the hypothesized function of NSSI in the
ECM (e.g., to diminish negative affect), but there is a possibility that rumination is
directly related to using NSSI to stop affective distress as rumination was found to be
significantly correlated with engaging in NSSI for ANR. Also, this finding highlights
how the ECM does not account for dissociation, a complex phenomenon which has been
repeatedly tied to NSSI (e.g., Osuch et al., 1999). It may be that dissociation results from
such “an extreme emotional cascade that the individual shuts his or her mind down”
(Selby & Joiner, 2009, p.227) and NSSI serves to disrupt episodes of dissociation (i.e.,
through the associated sight of blood or pain) and bring the individual out of this
unpleasant state.
Complementing these findings, there may be neurobiological foundations to
support that dysregulated behaviors like NSSI distract from rumination. According to
Ray et al. (2005) when non-BPD participants underwent an induced rumination
procedure (i.e., ruminated on negative affect) this correlated with increased activation in
neural structures (i.e., the left ventrolateral prefrontal cortex and left amygdale) which

25
activate during the experience of negative affect (Phan et al., 2003). Additionally,
through a self-injury proxy in patients with BPD, Schmahl et al. (2006) found that
increases in pain decreased activity in the amygdala. Based on the findings of these
studies, Selby and Joiner (2009) propose that emotional cascades may increase activity in
the amygdala, while dysregulated behaviors such as NSSI may then decrease activity in
this same area.
The ECM is a promising theoretical framework that clarifies why individuals may
engage in NSSI rather than other behaviours to cope with intense negative affect and why
individuals do not always use NSSI to regulate their affect. Also, it goes further than
previous models in proposing a pathway for how NSSI works to regulate affect.
Importantly, although the ECM focuses on the dissipation of rumination as the key to the
affect regulating property of a dysregulated behaviour, in the case of NSSI other potential
mechanisms have been proposed (e.g., opioid; Chapman et al., 2006). Future research on
the ECM is needed to clarify how it relates to these other potential affect regulating
mechanisms. Further evaluation of the ECM in adolescents and how other correlates
(e.g., dissociation) of NSSI relate to it is also needed.
Co-Rumination
Having reviewed literature pertaining to the prevalence, correlates, functions, and
models of NSSI, it is apparent that while literature on this subject is burgeoning, much
remains to be discovered regarding NSSI behaviour in adolescence. Adolescence is a
period with distinct developmental and environmental differences that offer a unique
context within which to study the onset, maintenance, and potential transmission of NSSI
behaviour (Whitlock & Knox, 2009). In adolescence, there are considerable

26
interpersonal transitions (Cyranowski, Frank, Young, & Shear, 2000; Hankin &
Abramson, 2001; Rudolph & Hammen, 1999) and adolescent friendships are high in
intimacy and emotional disclosure, particularly among girls (Buhrmester & Furman,
1987; Furman & Buhrmester, 1992). When faced with stressful experiences adolescents
are also more likely to rely on peers for social support (Harter, Stocker, & Robinson,
1996), and thus discussions of problems and associated negative feelings are frequent
(Rose, 2002). Traditionally, these supportive friendships have been viewed as protective
(Bukowski et al., 1996); however, Rose (2002) has proposed that certain facets of these
friendships, specifically the tendency to co-ruminate, may be maladaptive and increase
risk for the development of affective distress.
Following is a review of co-rumination and the research that supports its role in
increasing affective distress and its possible connection to NSSI behaviour in adolescents.
Specifically, upon reviewing the research which supports the role of co-rumination in
increasing affective distress in adolescents, this review will explore the possibilities that
co-rumination is either directly linked to the frequency of NSSI or moderates the
association between distress (i.e., depression) and NSSI. Additionally, the role of
stressful life events as a moderator of the proposed direct relationship between NSSI and
co-rumination will be explored.
What is co-rumination? Co-rumination is defined as “excessively discussing
personal problems within a dyadic relationship” (Rose, 2002). Like self-disclosure, corumination involves sharing personal thoughts and feelings. However, whereas selfdisclosure can involve any personal topic and can be brief, co-rumination involves an
excessive focus on problems and concerns and involves mutual encouragement of

27
problem talk. Co-rumination is similar to rumination in that they both involve a negative
focus on the details of problems or dwelling on negative affect. However, whereas
rumination is a cognitive, solitary process, co-rumination is a social, conversational
process. While co-rumination and depressive rumination are distinct constructs (Rose,
2002; Calmes & Roberts, 2008),“co-rumination’s negative, repetitive, non-solutionfocused nature, as opposed to its overlap with intimate sharing or self-disclosure,
accounts for the relationship between friend-based co-rumination and depressive
outcomes. In other words, it is the manner in which friendship pairs are discussing
problems, as opposed to the fact that they are discussing problems that makes corumination depressogenic” (Calmes & Roberts, p.587).
Observational research (Rose, Schwartz, & Carlson, 2005) has shown that friends
in relationships characterized by high co-rumination responded to problems with more
support and acknowledgement than those in relationships low in co-rumination. This
finding suggests that “to the casual observer co-rumination might appear to be a pleasant
supportive process, which would make it a process that could be easily overlooked as a
contributor to negative outcomes like depression” (Bukowski, Adams, & Santo, 2006,
p.27). Yet, in co-rumination, friends focus on negative affect and excessively discuss,
revisit, and speculate on problems, mentioning unanswerable questions and concerns
about a problem and its potential implications. For example, consider an adolescent who
has just experienced criticism from a peer and then repeatedly talks about what happened
with a friend, focusing on details of the experience, their negative feelings, and
speculating about possible causes and consequences of this experience. These friends
converse throughout their day at school and then continue the conversation on the phone

28
after school. While such an intense emotional conversation may initially increase
feelings of closeness within the friendship, and may appear like normal self-disclosure to
adults, “peer relations based on coruminative strategies may not only fail to buffer
individuals from more internalized distress but actually provide a venue for developing
greater risk” (Stone, Uhrlass, & Gibb, 2010, p.597).
Co-Rumination, friendship quality, and affective distress. Rose (2002)
initially found support for the maladaptive role of co-rumination using a sample of 608
students in third, fifth, seventh, and ninth grade. Co-rumination was found to be more
common within female than male relationships in childhood and adolescence and was
positively correlated with internalizing symptoms (i.e., depression and anxiety). The
differing levels of co-rumination between genders also became more pronounced in
adolescence, coinciding with the emergence of gender differences in depression (NolenHoeksema & Girgus, 1994). Additionally, higher levels of co-rumination predicted
greater quality, close friendships. In other words, co-rumination acted as a mediator for
the relationships between gender and emotional distress, and gender and friendship
satisfaction. In particular, higher levels of co-rumination in females’ friendships
contributed to females’ having higher levels of depression and anxiety, as well as greater
friendship satisfaction compared to males, suggesting that an individual’s gender may
determine whether friendship is protective in nature.
Rose et al.’s (2007) study sought to extend upon Rose’s (2002) research using a
longitudinal design in order to determine the temporal relationships between corumination and friendship and emotional adjustment. On two separate occasions, six
months apart, 813 adolescent participants in third, fifth, seventh, and ninth grade, filled

29
out a series of questionnaires. Again, females reported greater levels of co-rumination
than did males. Also, coinciding with the appearance of gender differences in level of
depressive symptoms in adolescence (Clark & Ayers, 1993) there was an interaction
effect where level of co-rumination was predicted by grade level and gender. The
researchers also described a transactional relationship between co-rumination and
adjustment. In females, co-rumination was found to predict both an increase in friendship
quality and depressive and anxiety symptoms, which in turn predicted an increase in corumination. In males, though, co-rumination did not predict an increase in depression
and anxiety; it only predicted an increase in friendship quality. While neither the
inclusion of only two time points, nor a time frame of only six months, makes for an ideal
longitudinal study, this research provided an important first indication of the possible
impact of co-rumination over time. Overall, this study concluded that co-rumination is
likely more problematic for females than males, and while females who co-ruminate
likely experience friendships of greater self-reported quality and appear to have strong
support systems, their risk for depression and anxiety is greater and needs to be assessed.
The link between co-rumination and affective distress was expanded upon in a
recent study by Stone et al. (2010). While previous research (Rose, 2002; Rose et al.,
2007) correlated co-rumination with depressive symptoms, Stone et al. found that this
relation generalizes to diagnosable episodes of depressive disorders. Specifically, in a
retrospective, behavioral high-risk design, where participants were 81 mother-child pairs,
current levels of co-rumination were found to predict children’s history of depressive
episodes. Children who reported currently engaging in high levels of co-rumination were
significantly more likely to have a history of at least one depressive episode, when

30
compared with children reporting lower current levels of co-rumination. Contrary to
previous studies (Rose, 2002; Rose et al., 2007), no significant gender differences in corumination were found. Also, gender did not significantly moderate the link between corumination and history of depressive disorders.
Starr and Davila (2009) recently completed a study which further elucidates corumination’s relation to both affective distress and friendship adjustment. While
attempting to replicate, and expand upon, previous findings made by Rose and colleagues
(Rose, 2002; Rose et al., 2007), Starr and Davila followed a sample of 83 early
adolescent girls, grades 7 and 8, over a one-year period. The self-report data replicated
previous findings made by Rose and colleagues; a positive cross-sectional association
between co-rumination and both depressive symptoms and positive friendship qualities
was found. Contrary to Rose et al.’s (2007) findings, co-rumination was not found to
predict increases in depressive symptoms over time. The researchers do note, however,
that while their effect sizes were statistically insignificant they were very similar to those
of Rose et al. (2007).
Stone et al. (2011) further investigated the unique role of co-rumination in
predicting the development and course of depression in adolescents. In a two year
prospective follow-up study, 106 early adolescent – parent pairs participated and
completed baseline measures of co-rumination, rumination, depressive symptoms, and
current and past history of clinically significant depressive episodes (including episode
duration and severity). Follow-ups at 6-, 12-, 18-, and 24-months assessed for onset of
new depressive episodes. As predicted, co-rumination was found to predict time to
depression onset over the 2-year follow-up and depressive episode duration and severity;

31
higher levels of co-rumination were associated with significantly shorter time to onset
and episodes of greater severity and duration. Furthermore, co-rumination was also
found to mediate the relationship between gender and depression onset, with girls
reporting significantly higher levels of co-rumination and exhibiting a significantly
shorter time to onset of depression than boys. These relationships were “maintained even
after baseline depressive symptoms and rumination were covaried, suggesting that the
influence of co-rumination is not simply due to its relation with these other variables”
(p.4). Co-rumination was found to be a stronger predictor of depression risk than
rumination in this study, highlighting the idea that, while co-rumination is associated with
higher friendship quality and closeness (Calmes & Roberts, 2008; Rose, 2002; Rose et
al., 2007; Starr & Davila, 2009) it appears to increase vulnerability to depression in
adolescents.
In endeavoring to expand upon co-rumination research Starr and Davila (2009)
found evidence that co-rumination may be depressogenic when it corresponds with
stressful events. Basically, when examining the association between co-rumination and
romantic experiences in adolescent girls, romantic involvement was found to be
positively correlated with co-rumination and moderated the effect of co-rumination on
depressive symptoms. Essentially, “co-rumination predicted increases in depressive
symptoms for girls with greater romantic experiences and decreases for girls with fewer”
(p.31) demonstrating that the maladaptive nature of co-rumination may not occur for all
girls, but those with greater levels of romantic activities. Starr and Davila suggest that
early adolescent girls are unprepared for and become stressed when they attempt to
manage the challenges of romantic experiences, and hypothesize that co-rumination may

32
be predictive of depressive symptoms only when it corresponds with a stressful
experience. Starr and Davila support their idea citing literature in which rumination was
found to be associated with prolonged and greater levels of depressed mood in response
to severe (e.g., earthquake) and mild (e.g., every day) stressors across a variety of
populations (Nolen-Hoeksema & Morrow, 1991; Nolen-Hoeksema, Parker, Larson,1994;
Nolen-Hoeksema, Morrow, & Fredrickson, 1993).
While Starr and Davila suggest that co-rumination may be predictive of
depressive symptoms only when it corresponds with a stressor, Byrd-Craven, Geary,
Rose, and Ponzi (2008) found evidence that co-rumination about a problem elicits a
biological stress response. Specifically, Byrd-Craven et al. examined whether a possible
biological correlate of co-rumination would help explain its association with affective
distress and friendship adjustment. Their study also addressed the methodological
weakness of relying solely upon self-report questionnaires for findings, used by the
majority of the above mentioned research. Participants were 48 undergraduate females
(24 friendship dyads) either assigned to a “problem talk” condition, where they were to
discuss a problem experienced by one of the participants, or to a control condition where
they were told to design a recreation center. Prior to engaging in either condition
participants completed questionnaires and provided saliva samples to measure their level
of the stress hormone cortisol. Following a 17 min discussion period, the friends in both
conditions were separated and given irrelevant magazines (e.g., home, garden, furniture
magazines) to read. After 15 min of reading, the participants’ saliva was collected again
to measure for peak post-stressor cortisol levels.

33
Byrd-Craven and colleagues (2008) found that even after controlling for selfreported levels of co-rumination and pre-stressor cortisol levels, individuals in the
problem talk condition experienced significant increases in cortisol levels. Interestingly,
while both conditions involved dwelling on problems it was solely the Problem Talk
condition that elicited an increase in cortisol levels. It appears that co-rumination “may
need to be about personal problems to be meaningful enough to elicit a biological stress
response” (p.491). In addition, while this lab experiment does not mirror what would
occur naturally, it does provide initial experimental evidence that co-rumination
intensifies women’s stress response. It is unknown though whether it was solely the
dwelling on negative affect, rather than engaging in the more analytical aspects of corumination (e.g., wondering about the possible causes and consequences of problems;
Byrd-Craven et al., 2008), that resulted in increased cortisol, or whether cortisol increases
were also amplified by the social nature of co-rumination. Apparently, the mere
discussion of a problem without actively problem solving within a friendship dyad can be
problematic.
Byrd-Craven et al.’s (2008) study provides a possible explanation for the
connection between co-rumination and emotional adjustment. Byrd-Craven et al. point
out how research has shown that a more accurate memory of problem details results from
a mild to moderate release of cortisol (Abercrombie, Kalin, Thurow, Rosenkranz, &
Davidson, 2003). A more accurate memory of problem details could have either a
positive or negative influence. Positively, a more accurate memory of problem details
could aid in problem solving efforts. Negatively, a more accurate memory of problem
details and subsequent distress could contribute to the higher levels of depressive and

34
anxious symptoms that often occur with co-rumination (Rose, 2002; Rose et al., 2007).
Overall, Byrd-Craven et al.’s study contributes to the growing literature on co-rumination
which states that co-rumination is linked with increased vulnerability to affective distress.
Co-rumination and NSSI in Adolescents
Upon reviewing literature pertaining to both NSSI and co-rumination it is
apparent that both are positively associated with affective distress. Given the role of corumination in increasing affective distress in adolescents, the following section argues
that co-rumination either moderates the association between depression and NSSI or is
directly linked to the frequency of NSSI. Additionally, the role of stressful life events as
a potential moderator of the proposed direct relationship between co-rumination and
NSSI will be presented.
Does co-rumination moderate the relationship between NSSI and
depression? Research on co-rumination, NSSI, and the ECM suggest that co-rumination
may act as a moderator between NSSI and depression. First, both co-rumination and
NSSI have been linked to depression. Studies have shown current levels of corumination to be positively correlated with depression (Rose, 2002; Rose et al., 2007;
Starr & Davila, 2009), predictive of children’s history of depressive episodes (Stone et
al., 2010), and predictive of increases in depressive symptoms over a 6 month period
(Rose, Carlson, & Waller, 2007). Furthermore, co-rumination was found to be a stronger
predictor of depression risk than rumination in a recent study with early adolescents
(Stone et al., 2011). Also, NSSI has been found to be associated with symptoms of
depression (Andover, Pepper, Ryabchenko, Orrico, & Gibb, 2005; Hawton et al., 2002;
Nixon et al., 2002; Nock et al., 2006; Klonsky et al., 2003; Ross & Heath, 2002) and is

35
most frequently carried out in order to diminish affective distress. For example, Nixon,
Cloutier, and Aggarwal (2002) found that affect regulation (e.g., “to cope with feelings of
depression”) was the most frequently endorsed reason for NSSI among hospitalized
adolescent self-injurers.
Second, as discussed by Starr and Davila (2009), co-rumination may function
similarly to rumination in exacerbating depressive symptoms in dysphoric individuals,
yet not exerting any affect on mood in non-dysphoric individuals (Nolen-Hoeksema,
1991). Therefore, adolescents who are not vulnerable to emotion dysregulation would
not experience any significant change in mood when co-ruminating, while emotionally
dysregulated adolescents like those who engage in NSSI, would experience heightened
depressive symptoms. It may be that co-rumination exacerbates depressive symptoms
and this drives adolescents to engage in NSSI for relief.
Third, further research on rumination and co-rumination suggest that corumination may moderate the relationship between depression and NSSI. Rumination
has been found to predict the onset and exacerbation of depression in children and
adolescents (Abela, Brozina, et al., 2002; Abela & Hankin, 2007; Nolen-Hoeksema,
Stice,Wade, & Bohon, 2007) and is proposed to do this by intensifying the impact of
negative affect on cognitive processing and by hindering the use of effective, problemsolving behaviors that could alleviate depressive symptoms (Nolen-Hoeksema 1987,
1991). Recently, Armey and Crowther’s (2008) findings indicate that the self-critical
focus of rumination, rather than a constructive reflection on a problem, is what
contributes to increasing negative affect. Co-rumination, with its focus on the negative
event and associated negative affect, is also linked to elevated depressive symptoms and

36
is not associated with constructive problem solving. These similarities suggest that corumination may similarly lead to NSSI behaviour in adolescents as described in the ECM
(e.g., Selby & Joiner, 2009). Examining the impact of co-rumination on adolescent NSSI
separately from rumination is justified since co-rumination has been found to mediate the
gender difference in depression during adolescence and to be a strong predictor of
depression risk, even after covarying for rumination, suggesting that it uniquely predicts
an increase in vulnerability for depression in adolescents (Stone et al., 2011).
In summary, research indicates that co-rumination is predictive of depression,
depression is predictive of NSSI behaviour in adolescents, and suggests co-rumination
may function similarly to rumination in the ECM. Accordingly, this study examined
whether co-rumination moderated the relationship between depression and NSSI in
adolescents.
Is co-rumination directly linked with NSSI? This study also explored whether
co-rumination is directly related to NSSI behaviour. With self-injurers’ lower distress
tolerance (Najmi et al., 2007; Nock & Mendes, 2008; Nock et al., 2008), the spike in
cortisol levels recorded by Byrd-Craven et al. (2008) following co-rumination may be
enough to activate an emotional cascade as described in the ECM (Selby et al., 2008;
Selby & Joiner, 2009). Alternatively, in a hyperaroused state due to an increase in
cortisol, a self-injurer may be incapable of utilizing more adaptive problem solving and
coping strategies. Recent research (Nock & Mendes, 2008) has supported the hypothesis
that since self-injurers are more prone to emotional reactivity and emotion dysregulation
they would have greater difficulty using social problem-solving skills when distressed.
Adolescent self-injurers were found to be less able to generate solutions to hypothetical

37
dilemmas after a stress-inducing task. Furthermore, while they were able to create the
same number of solutions relative to non-self injurers they gave more maladaptive
solutions and reported lower self-efficacy for utilizing adaptive solutions. While the
repetitive focus on problems in co-rumination may lead to the generation of solutions in
non-self-injurers, it may hinder effective problem solving in self-injurers. As a result,
self-injurers may be more likely to engage in NSSI after co-rumination due to an increase
in negative affect (as previously discussed) or due to the inability to generate, or follow
through on, any adaptive alternative solutions to difficulties.
Also, as described during the section on the ECM, research suggests that
rumination is directly linked with NSSI. Borrill et al., (2009) found that undergraduate
students who engaged in self-injury had higher levels of self-reported rumination, and
rumination significantly predicted self-injury status. Another study by Hilt, Cha et al.,
(2008) found that rumination did not moderate the relationship between depression and
engaging in NSSI to stop affective distress, but may be directly related since rumination
was found to be significantly correlated with engaging in NSSI to stop affective distress.
Considering these findings, this study explored whether co-rumination between friends
acts similarly to rumination and determined whether co-rumination is directly linked with
NSSI behaviour in adolescents.
In addition, this study looked at how the number of stressful events experienced
impacted the proposed direct association between co-rumination and NSSI. Specifically,
this study examined whether stressful life events moderated the association between corumination and NSSI behaviour in adolescents. First, research states that individuals who
self-injure report greater subjective levels of experienced emotional distress when faced

38
with stressful events (Najmi et al., 2007; Nock et al., 2008) and have been found to be
less able to tolerate distress than non-injurers (Nock & Mendes, 2008). It is possible that
even a small stressful event would be sufficient to trigger emotional dysregulation (i.e.,
emotional cascade according to the ECM; Selby et al., 2008; Selby & Joiner, 2009) in a
self-injurer, and drive an adolescent to engage in NSSI. Second, a recent study by
Hankin and Abela (2011) also found more stressful life events significantly differentiated
youth who engaged in NSSI from those who did not. Following, it is likely that the more
stressful events an individual experiences, the more likely an individual will engage in
co-rumination and trigger an emotional cascade and thus engage in NSSI. Third, again
turning to research involving rumination, Selby et al. (2010) found that higher levels of
rumination combined with a greater number of painful events predicted a higher
frequency of NSSI in undergraduate students.
In addition, the type of stressor experienced by an adolescent may be relevant to
the relationship between co-rumination and adolescent NSSI. Research suggests that
stressful interpersonal events are linked to episodes of NSSI in adolescents (Hilt, Cha et
al., 2008). Interpersonal stressors, particularly those that are dependent interpersonal
stressors have also been found to contribute to increased co-rumination (Hankin, Stone,
& Wright, 2010). Dependent interpersonal stressors are those that the individual may
have contributed to through their own characteristics or behaviors (e.g., fight with friend).
The effects of gender, age, and peer NSSI. Past research indicated that gender,
age, and peer NSSI would influence the outcome of this study. While the majority of
studies have found co-rumination to be more common within female than male
relationships in childhood and adolescence (Rose, 2002; Rose et al., 2007), one study

39
found no gender differences in level of co-rumination (Stone et al., 2010). The
prevalence of co-rumination also increases from childhood through adolescence (e.g.,
Rose, 2002; Rose et al., 2007). Depression, similarly, is more common in females than
males (e.g., Hankin et al., 1998; Hankin, Wetter, & Cheeley, 2008; Wichstrom, 1999),
and becomes more prevalent in adolescence (Nolen- Hoeksema & Girgus, 1994). In
regards to NSSI, research suggests that NSSI is more prevalent among females, in both
clinical and community settings (Nock, 2009), though this gender difference may not be
clinically significant.
Lastly, this study also attempted to control for peer NSSI. Youth may imitate
NSSI behaviours that they observe in their peers. Indeed, the contagion of NSSI has been
observed in psychiatric (Rosen & Walsh, 1989; Walsh & Rosen, 1985) and community
based samples (Prinstein et al., 2007) of adolescents and there is growing evidence that
the contagion of NSSI is more common than previously believed (Fennig et al., 1995).
NSSI has been reported to have a contagion effect among adolescents who believe it to be
a helpful coping strategy (Derouin & Bravender, 2004; Hodgson, 2004) and recent
research suggests that “adolescents also may be socialized into engaging in NSSI
behaviour within their close friendships” (Heilbron & Prinstein, 2008, p.170). Among
102 adolescent psychiatric inpatients it was found that an adolescents’ increasing NSSI
behaviour was longitudinally associated over 18 months with their perception of friends’
NSSI behaviour. Results from a community-based sample of adolescents revealed
similar results. Increases in adolescents’ own NSSI behaviour was longitudinally
associated with their best friends’ reports of NSSI over a two year period (Prinstein et al.,
2007). This study attempted to control for the NSSI behaviour of adolescents’ best

40
friends to help ensure that the findings of this study were due to the relationship between
co-rumination and NSSI, not due to peer NSSI behaviour.
The Current Study
This study further expanded upon the burgeoning research on NSSI in
adolescents. Specifically this study delineated the relationship between NSSI and a
relatively new construct in the literature, co-rumination. The association between these
two constructs had not yet been investigated and offers promising insight into the
significance of peer influence effects in adolescent NSSI. First, this study investigated
whether co-rumination was directly related to NSSI behaviour in adolescents. Second,
this study investigated whether co-rumination moderated the association between
affective distress (i.e., depression) and NSSI. Third, this study investigated whether the
number of stressful events experienced influenced the proposed direct association
between NSSI and co-rumination. The following hypotheses were proposed:
Hypothesis 1: Adolescent co-rumination will be positively correlated with the frequency
of adolescent NSSI behaviour.
Hypothesis 2: Co-rumination will moderate the association between depression and the
frequency of NSSI behaviour in adolescents. Specifically, co-rumination was
hypothesized to enhance the positive correlation between adolescent depression and the
frequency of adolescent NSSI behaviour.
Hypothesis 3: Stressful life events will moderate the association between co-rumination
and the frequency of NSSI behaviour in adolescents. Specifically, stressful life events was
hypothesized to enhance the positive correlation between adolescent co-rumination and
the frequency of adolescent NSSI behaviour.

41
CHAPTER III: METHODOLOGY
Research Design
Single Time Point Survey Design. This study was conducted using a single time
point survey design. In this manner, differences between groups at a single point in time
were examined with this descriptive, cross-sectional approach (Mertens, 2005); it was
only necessary for the participants to complete one set of questionnaires. Being a
correlational design, this study is only able to convey the relationships between variables,
but is unable to declare any causal effects. The correlational approach allows for the
exploration of co-rumination in the proposed population. Additionally, in establishing
the relationships between co-rumination and NSSI, and depression, this study provides a
basis from which to ascertain any possible causal relationships through future study.
Participants
Sample Size. In order to establish generalizability, a power analysis determined
that a sample size of 89 (N = 89) would be required. This sample size was established by
recognizing the two predictors in this study and using the conventional alpha level of
significance (α = .05), a high degree of power (β = 0.95) and a medium effect size (f2 =
0.15). A medium effect size was chosen based on research reporting significant
correlations between NSSI and depression and co-rumination and depression that are of
low-moderate to large strength. NSSI has been found to have a significant positive
correlation with depression (i.e., r = .215 at baseline and r = .199 at 6 months, p < .001;
O’Connor et al., 2010, r = .52, p < .05 at baseline and r = .44, p < .01 at 9 months; Guerry
& Prinstein, 2010). Co-rumination has been found to have a significant positive

42
concurrent association with depression (i.e., r = .33 at baseline and r = .20 at 6 months, p
< .0001; Rose et al., 2007).
Inclusion and exclusion criteria. Criterion sampling was utilized for this study.
Eligible participants for this study consisted of adolescents, grades 7 through 12, from the
participating secondary schools. Furthermore, the sample was inclusive of both
adolescents who engage in NSSI and those who do not. It was the researcher’s desire that
this open inclusion would increase the representativeness of the sample and help avoid
selection bias. Essentially, by going into classrooms rather than advertising for
participants, it was hoped that there would be less systematic error due to differences
among the true population and study population. Ethically, in order for an adolescent to
be eligible, they must have been (a) able to read and comprehend English, (b) 13 through
18 years old and, (c) have the consent of a parent/guardian and (d) personally assent to
participate in the study. Once the data was collected, and the prevalence of NSSI in the
community sample calculated, only data pertaining to individuals who engaged in NSSI
was retained for further analyses.
Characteristics. Participants in this study were students from the middle and
high schools in Fort St. John, British Columbia. Adolescents were recruited from
mainstream and alternate programs in order to more broadly reflect the population within
the community. Of the 770 students (544 in middle school, grades 7 to 9, and 226 in high
school, grades 10 to 12) who were given a parent consent form, 35.6% (186 from the
middle schools and 88 from the high school) returned a signed parent consent form and
85.4% of these (149 from the middle schools and 85 from the high school; 55.6 %
female) completed the survey.

43
It was expected that between 7 and 16 percent of community-based adolescent
participants would endorse that they had engaged in NSSI in the past 12 months (Hilt,
Nock, Lloyd-Richardson, & Prinstein, 2008; Muehlenkamp & Gutierrez, 2004), while
lifetime prevalence was expected to center around 15-20% (Heath et al., 2009). Within
the overall sample of adolescent students in this study who completed the survey, 136
(58.1%) of the 234, reported that they had physically hurt themselves on purpose in the
past year, and an additional 10 (4.3%) reported they had engaged in NSSI prior to the
past year. Overall, a lifetime frequency of 62.4% was found in the overall sample. This
percentage is high, though other studies have reported similarly high percentages (e.g.,
56% lifetime rate and 36% in previous year Hilt, Cha et al., 2008; 46.5% in previous year
Lloyd-Richardson et al., 2007). In addition, two adolescent participants reported NSSI
behaviour, but reported that this behaviour was done with suicidal intent and they were
not included in the 136. Of the 136 participants who reported they had engaged in NSSI
in the past year, 92 fully completed the survey.
Procedure
Permission to conduct this survey was obtained from relevant school district #60
personnel. With the collaboration of school administrators and teachers, participating
classes were determined based on grade and teacher interest.
Student recruitment, class presentations, and questionnaire administration.
The researcher contacted teachers at the middle and high schools and asked to visit their
classrooms for 5-10 min at a pre-determined date to give a brief overview of the study
(Appendix A) and to distribute the parental consent form (Appendix B). Rather than
being introduced as a study on NSSI, students were informed that the purpose of the

44
study was to investigate the different ways they cope with stress and how stress impacts
how they feel. It was described in this manner in order to avoid acquiring a self-selected
sample, to prevent any stigmatization about NSSI, and to address the potential ethical
concerns that may arise regarding the social influence and contagion effects of NSSI
(Gratz, 2006; Hodgson, 2004). Students were informed that all their answers on the
questionnaires would be confidential and that participating in the study was completely
voluntary. They were encouraged to participate, but were notified that they could
withdrawal from participating at any time. Students were instructed to return a signed
parental consent form by a pre-determined date.
On the pre-determined date, a brief presentation (Appendix C) was made to each
class including: a review of the objectives of study, parent and participant consent,
questionnaire administration procedures, incentives, confidentiality/ anonymity, and
question answering. Afterwards, survey packages were distributed to the participants
during their class. It was expected that the six questionnaires would take approximately
30-40 min. Students were offered the opportunity to fill out a prize draw form if they had
agreed to participate in the survey. Students were made aware that they were entering a
draw to win one of three 50-dollar gift cards for iTunes. If students withdrew from the
study their prize draw form would remain eligible. Students who did not return parent
consent forms or who chose not to participate were directed to quietly work on a class
assignment. All participating students were asked to first read the Adolescent Assent
Form (Appendix D) attached to the front of the survey package which reiterates all
information presented orally. Following this, students were asked to give personal assent
by signing the assent form. Students were informed that the researcher would be

45
available to answer questions related to comprehension during the class period given to
complete the survey. A follow up option was included on the last page of the survey
(Appendix E) so students could indicate if they would like to be contacted at a later date
to learn the results of the study.
Upon completion of the survey, consent forms and follow up requests were
removed from the survey package and paired with parent consent forms to ensure
anonymity. Following the completion of the survey package a short debriefing
conversation (Appendix F) with students was facilitated by the researcher to determine
student reactions. Questionnaires were stored according to the university’s ethics
committee regulations. All item responses from the questionnaires were entered into and
stored within the Statistical Package for Social Sciences (SPSS). The SPSS data files
only included the participant’s assigned ID number and no identifiable information.
Offers to school administration. To compensate school personnel for the time
and effort invested in the research project they were offered a variety of services
dependent on individual needs and interests of the school. The researcher was prepared
to provide a review of the literature in the areas of peer influence and non-suicidal selfinjury (NSSI) and a lecture to staff on the topic of NSSI.
Measures
Students were given a questionnaire package that included the following:
demographic questions, Center for Epidemiological Studies-Depression Scale (CES-D),
Co-Rumination Questionnaire (CRQ), Functional Assessment of Self-Mutilation
(FASM), Peer NSSI questionnaire, and Adolescent Life Events Questionnaire (ALEQ).

46
Demographic information. Initial items of the questionnaire package relate to
the collection of demographic information (see Appendix G). Questions answered by all
participants focused on categorical responses to gender, age, grade level, ethnicity, and
socio-economic status.
Depression. The Center for Epidemiological Studies-Depression Scale (CES-D;
Radloff, 1978) is a widely used 20-item self-report measure for the assessment of
depression symptoms (see Appendix H). It has been used in both normative and clinical
samples of adolescents (Hogue & Steinberg, 1995; Roberts, Andrews, Lewinsohn, &
Hops, 1990). The CES-D asks respondents to indicate the number of days during the past
week that they had experienced a range of feelings or behaviours (0 = less than 1
day/rarely or none of the time to 3 = 5-7 days/most or all of the time). All items are
summed; positive emotion items are reverse coded. Scores range from 0 to 60, with
higher scores indicating higher levels of depressive symptoms. The suggested cutoff
score is 15 (Weissman, Orvaschel, & Padian, 1980); that is, scores over 15 can be
indicative of significant levels of depressive symptoms in children and adolescents. The
CES-D has been reported as a four factor model in both adults and adolescents (Chabrol,
Montovany, Chouicha, & DuConge, 2002; Hales et al., 2006; Radloff, 1978) and (the
factor structure) has been shown to be stable when re-administered 1 month later (Roberts
et al., 1990). The four factors are depressed affect (DA), positive affect (PA), somatic
and retarded activity (SR), and interpersonal (IP; Hales et al., 2006). The factor structure
and reliability of the CES-D has been validated in screening for depression in adult and
adolescent populations in clinical, community, and Internet settings, as well as across
African-Americans and Caucasian-Americans (Carpenter et al., 1998; Chabrol et al.,

47
2002; Cuijpers, Boluijt, & van Straten, 2008; Hales et al., 2006; Radloff, 1991). Good
psychometric data exist for the use of the CES-D with adolescents, including high
internal consistency (e.g., Cronbach’s alpha .85 – .92; Chabrol et al., 2002 and Prinstein,
Boergers, & Spirito, 2000, respectively).
Co-rumination. The 27-item Co-Rumination Questionnaire (CRQ; Rose, 2002)
was used to assess the extent to which youths typically co-ruminate with close same-sex
friends (see Appendix I). There are three items for each of nine content areas assessed:
(a) frequency of discussing problems, (b) discussing problems instead of engaging in
other activities, (c) encouragement by the focal child of the friends’ discussing problems,
(d) encouragement by friend of the focal child discussing problems, (e) discussing the
same problem repeatedly, (f) speculation about causes of problems, (g) speculation about
consequences of problems, (h) speculation about parts of the problem that are not
understood, and (i) focusing on negative feelings. Participants rate each item on a 5-point
Likert scale. Co-rumination scores are the mean ratings of the 27 items. Examples are
“When we talk about a problem that one of us has, we usually talk about that problem
every day even if nothing new has happened” and “when we talk about a problem that
one of us has, we try to figure out everything about the problem, even if there are parts
that we may never understand.” The CRQ was initially developed by Rose (2002) to
assess the extent that children, grades 3 to 9, co-ruminate with close same sex friends.
The CRQ has been used with children grades 3 through 11, with mother-daughter dyads
and in undergraduate populations (e.g., Byrd-Craven et al., 2008; Calmes & Roberts,
2008; Rose et al., 2007; Starr & Davila, 2009; Stone et al., 2011; Waller & Rose, 2009).
Preliminary findings indicated support for the convergent validity of the construct of co-

48
rumination; it has been found to be positively correlated to measures of both rumination
and self-disclosure (rs = .46 and .61, respectively; Rose, 2002). The CRQ has
demonstrated moderate retest reliability (6 months, r = .54; Rose et al., 2007), and
excellent internal consistency in nonclinical samples (αs = .96-.97; Byrd-Craven et al.,
2008; Rose, 2002; Rose et al., 2007).
Non-suicidal self-injury. Participants’ engagement in NSSI over the last 12
months was evaluated using the Functional Assessment of Self-Mutilation (FASM;
Lloyd, 1998). The FASM (see Appendix J) is a self-report measure that assesses the
frequency, methods and function of NSSI and includes information about the age of
onset, suicidal intent, degree of physical pain experienced, how long they thought about it
before doing it, whether or not they were taking drugs or alcohol during NSSI, and
whether or not medical treatment was received. As in other studies (e.g., Hankin &
Abela, 2011), the 23 questions on the FASM used to ascertain the function of NSSI were
not included for this study. The measure was developed using psychiatric and normative
samples of self-injuring adolescents thereby justifying its use in a community sample.
The FASM has demonstrated adequate psychometric properties in adolescent
populations (Guertin, Lloyd-Richardson, Spirito, Donaldson, & Boergers, 2001; LloydRichardson, Perrine, Dierker, & Kelley, 2007). It has been used in normative and
psychiatric samples, and has adequate internal consistency of α = .65 (Guertin et al.,
2001; Nock & Prinstein, 2004). The FASM has demonstrated concurrent validity as
evidenced by significant associations with measures of suicide ideation, past suicide
attempt (Guertin et al., 2001), recent suicide attempt, hopelessness and depressive
symptoms (Nock & Prinstein, 2005).

49
Peer NSSI. Questions to tap social influence, specifically peer engagement in
NSSI were developed and added to the end of the FASM (see Appendix K). These
questions stated, “Think of your best or closest friends. Have your friends deliberately
harmed themselves in any of the above ways (without intending to kill themselves)?” If
yes, how many times would you estimate they have hurt themselves in the past year?
Similar questions have been developed in previous research to tap social influence (e.g.,
Heath et al., 2009).
Stressful life events. The Adolescent Life Events Questionnaire (ALEQ; Hankin
& Abramson, 2002; see Appendix L) was designed to assess the occurrence of a broad
range of negative events/stressors typically reported by adolescents, including school
problems (i.e., “You got into trouble with the teacher or principal”), relationship
difficulties (i.e., “You found out your boyfriend/girlfriend was cheating on you”), and
family problems (i.e., “you fought with your parents over your personal goals, desires, or
choice of friends”). Each of the 57 events is rated for frequency over a period of time
predetermined by the researcher (e.g., 5 weeks; Hankin et al., 2010, one month; Skitch &
Abela, 2008, 3 months; Hankin & Abela, 2011) on a Likert type scale ranging from 0
(never) to 4 (always), with higher scores reflecting a greater number of negative life
events. A time frame of 12 months was chosen for the present study to correspond with
the time frame over which NSSI was also assessed. These 57 events can be categorized
into interpersonal (e.g., family) and noninterpersonal domains (e.g., academics, see
Hankin & Abramson, 2002) and independent (i.e., not related to the individuals
characteristics) versus dependent (i.e., individual’s characteristics or behavior may have
contributed) types of events. In Hankin and Abramson’s original (2002) study, with a

50
sample of adolescents aged 13 to 18, the ALEQ had an internal consistency of .94 and
test re-test over 2 weeks was .65. More recent research has further established the
reliability and validity of the ALEQ in adolescent populations (e.g., Hankin, Wetter,
Cheely, & Oppenheimer 2008; Hankin et al., 2010) and shown that is has high internal
consistency (α = .92-.93; e.g., Auerbach, Abela, Ho, McWhinnie, & Czaikowska, 2010;
Skitch & Abela, 2008).
Screening of the Data
Prior to analyzing the hypotheses of this study, the research data was checked for
errors in coding, missing data, outliers, and violations of the applicable statistical
assumptions involved in the planned analyses: bivariate correlation and hierarchical
multiple regression. All statistical analyses were performed using data from those
adolescents who had engaged in NSSI in the past year and had fully completed the survey
(N = 92).
Of the 92 adolescents who had engaged in NSSI in the past year, no data was
missing for the Center for Epidemiological Studies-Depression Scale (CES-D), CoRumination Questionnaire (CRQ), Functional Assessment of Self-Mutilation (FASM), or
the Adolescent Life Events Questionnaire (ALEQ). The Peer Nonsuicidal Self-Injury
(NSSI) Questionnaire contained missing data for 12 participants. While all 92
participants completed the question of whether a peer had engaged in NSSI or not
(yielding a complete dichotomous categorical variable), 12 did not report a frequency of
NSSI for their peers. These 12 missing values were replaced with the mean value.
Variables were examined for potential univariate outliers using boxplots.
Scatterplots, histograms, and box plots were visually examined to look for skewed

51
distributions and non linear relationships. These examinations revealed that the CESD,
FASM and Peer NSSI scales were positively skewed, with both frequency scores from
the FASM and Peer NSSI scales showing extreme positive skews, with skewness values
of 4.04 (SE = .25) and 5.05 (SE = .25), respectively.
The CESD, FASM, and Peer NSSI were positively skewed and violated the
assumption of normal distribution of scores. The positive direction of the skew appeared
reasonable considering a non clinical sample of adolescents was used. The FASM and
Peer NSSI box plots also showed numerous extreme outliers (i.e., more than three
interquartile ranges from the box in the boxplot). A logarithmic transformation of the
FASM and Peer NSSI total scores was performed, which removed all extreme outliers.
Since 29 participants indicated that their peers did not engage in self-injury, a logarithmic
transformation of these variables was not possible, removing 29 participants from the
data set. Of the remaining 63 values, there were no longer any extreme outliers present,
though the Peer NSSI box plot continued to show 4 outliers (at the high upper limit). The
10 high scores subsequent to these outliers were examined to see what intervals they were
increasing at; on average Peer NSSI scores were increasing in increments of 11. Peer
NSSI outliers were changed to the next highest score plus 11 in order to more accurately
reflect the distribution shape. Changing the value of the outliers, rather than removing
the data, was the preferred method because the data may have been an accurate
representation of the construct being assessed and there was no other explanation for the
elevated scores (Field, 2005). After changing the values of the outliers, two outliers
remained at the high upper limit. Upon examination, the 5% Trimmed Mean (i.e., 1.19)
and the Mean (i.e., 1.19) values were determined to be the same; given this, these two

52
remaining outliers were retained in the data file. The mean value of the CESD underwent
square root transformation, resulting in an approximately normal distribution of the data.
The box plot of the transformed data for the CESD showed 3 outliers (at the lower limit).
These outliers were changed to the next lowest score minus the average interval found
when examining the bottom 10 intervals of the CESD. It was determined that the
transformed data for the CESD was decreasing in increments of 0.05, and the outliers
were changed accordingly. Once the CESD, FASM, and Peer NSSI underwent these
transformations, a visual examination of the normality plots and histograms indicated that
the distributions were more normal. The transformed variables were used for all
statistical analyses.
Reliability of Research Measures
To obtain an estimate of internal consistency and therefore evaluate the reliability
of the research measures, Cronbach’s Alpha coefficients were calculated for each
measure (see Table 1). The Cronbach’s Alpha for the use of different forms of NSSI was
α = .63 for self-injurers; this reliability is consistent with past research (Lloyd-Richardson
et al., 2007) and while low, it is consistent with previous research findings which has
shown that just because an individual engages in one form of NSSI, does not necessarily
mean he or she will engage in another (Selby et al., 2010). All the remaining measures
exhibited acceptable to very good (ranging from .74 to .96) internal consistency scores.

53
Table 1
Cronbach’s Alpha for Research Measures for the all Participants and Separately for
Self-Injuring Participants
________________________________________________________________________
Scale
Cronbach’s Alpha (NSSI only)
Items
________________________________________________________________________

1. CES-D

.91 (.89)

20

2. CRQ

.96 (.96)

27

3. FASM

.77 (.63)

12

4. Peer NSSI

.84 (.81)

12

5. ALEQ

.94 (.93)

57

________________________________________________________________________
Note. CES-D = Center for Epidemiological Studies-Depression Scale (square root transformation); CRQ =
Co-Rumination Questionnaire; FASM = Functional Assessment of Self-Mutilation (log transformation);
Peer NSSI = Peer Non-Suicidal Self-Injury Questionnaire (log transformation); ALEQ = Adolescent Life
Events Questionnaire (ALEQ).

54
CHAPTER IV: RESULTS
Results presented from this study include the demographic statistics regarding the
prevalence, frequency, and characteristics of nonsuicidal self-injury (NSSI) behaviours
used and the level of depressive symptoms, co-rumination, and stressful life events
experienced in the sample of adolescent students. In regards to the main purpose of this
study, a Pearson correlation was conducted to determine whether there was a relationship
between co-rumination and NSSI frequency in adolescents. Additionally, two
hierarchical multiple regression analyses were conducted to determine whether corumination moderated the relationship between depression and NSSI frequency, and
whether stressful life events moderated the relationship between co-rumination and NSSI
frequency. Further post-hoc analyses were also included.
Descriptive Statistics
Description of NSSI participants. Table 2 presents the descriptive data (means
and standard deviations) associated with the demographic variables. Self-injuring
participants were 55.4% female; 80.4% White, 8.7% Mixed Ethnicity, 4.3% Aboriginal,
3.3% Asian, 2.2% Black, and 1.1% other. Self-injuring participants had a mean age of
14.7 (SD = 1.9) years and 56.5% attended middle school (i.e. grades 7 to 9) while the
remaining 43.5% attended the local high school (i.e. grades 10 to 12). The majority of
these self-injuring participants resided with two parents (78.3%), who were married
(71.7%), lived in a house owned by their family (75.0%), and had mothers (48.9%) and
fathers (87.0%) who were employed full time.

55
Table 2
Demographic Variables of Participants who Engaged in NSSI in the Past Year
________________________________________________________________________
Variable
Percentage
Mean
SD
________________________________________________________________________
Age
14.70
1.88
Gender (% female)
55.4
Grade (% Middle School; grades 7 to 9)
56.6
9.33
1.91
Ethnicity
Aboriginal Person
4.3
Asian
3.3
Black
2.2
White
80.4
Mixed Ethnicity
8.7
Other
1.1
Housing
Rented House/Duplex
14.1
Rented Apartment
3.3
Own House/Duplex
75.0
Foster Home
2.2
Other
4.3
Who Live With
Live with single parent
15.2
Live with two parents
78.3
Live with non relatives
3.3
Live with relatives
2.2
Other
1.1
Parent’s Marital Status
Married
71.7
Separated
2.2
Divorced
10.9
Never married
12.0
Not Known
3.3
Employment (Mother / Father)
Working full time
48.9 / 87.0
Working part time
26.1 / 1.1
Home duties
13.0 / 0.0
Not working
6.5 / 2.2
Student
1.1 / 1.1
Retired
1.1 / 1.1
Other
0.0 / 1.1
Not Known
3.3 / 6.5
________________________________________________________________________

56
Table 3 summarizes the scores (i.e., ranges, means, standard deviations) on the
measures for the sample of adolescents who engaged in NSSI in the past year, as well as
separately by gender. To determine whether the mean scores on the variables were
significantly different between males and females an independent samples t test was used.
Overall, mean depression and co-rumination scores were significantly different between
genders. Females (M = 22.96, SD = 10.36) scored significantly higher than males (M =
16.68, SD = 11.38) on depressive symptoms (CES-D), t(90) = -2.78, p < .01 (two-tailed).
Females (M = 2.75, SD = .78) also had significantly higher levels of co-rumination
(CRQ) than males (M = 2.17, SD = .84), t(90) = -3.42, p = .001 (two-tailed). These
gender differences are consistent with past research (e.g., Rose, 2002; Rose et al., 2007;
Hankin et al., 1998; Hankin, Mermelstein, & Roesch, 2007; Hankin et al., 2008). The
intercorrelations among the study variables are presented in Table 4. Linearity was
established between the variables by examining scatterplots.
A chi square analysis showed a significant gender difference in the prevalence of
NSSI (as endorsed on the FASM) in the overall sample of adolescent students, with 53%
of males and 68% of females indicating an engagement in NSSI behaviours in the past
year; χ2 (1, n = 222) = 4.62, p = .03, phi = .15. The most frequently cited methods of
NSSI on the FASM were picking at a wound (63.0%), biting self (58.7%), hitting self on
purpose (40.2%), scraping skin (27.2%), cutting or carving skin (23.9%), picking at areas
of body until drawing blood (20.7%), pulling hair out (17.4%), and burning skin (17.4%).
Other methods that were reported include inserting objects under skin (12.0%) other
methods (8.7%; e.g., snapped wrist with elastic band), erasing skin (7.6%), and giving

57
Table 3
Range, Means and Standard Deviations for Measures by Gender in Self-Injuring
Participants (N = 92)
________________________________________________________________________
Scale
Range
Mean
SD
________________________________________________________________________
1. CES-D
Males (n = 41)
Females (n = 51)

0.10-2.40
0.10-2.40
0.15-2.20

1.01
0.84
1.15

0.56
0.56
0.52

2. CRQ
Males
Females

1.04-4.37
1.04-4.30
1.19-4.37

2.50
2.17
2.75

0.85
0.84
0.78

3. FASM
Males
Females

1.00-1300.00
1.00-200.00
2.00-1300.00

88.25
28.71
136.12

198.24
43.63
254.47

4. Peer NSSI
Males (n = 38)
Females (n = 42)

0.00-174.00
0.00-174.00
0.00-174.00

20.08
13.02
25.75

35.52
28.89
39.44

5. ALEQ
0.07-2.39
1.23
0.55
Males
0.07-2.39
1.11
0.57
Females
0.25-2.30
1.32
0.52
________________________________________________________________________
Note. CES-D = Center for Epidemiological Studies-Depression Scale (square root transformation); CRQ =
Co-Rumination Questionnaire; FASM = Functional Assessment of Self-Mutilation (log transformation);
Peer NSSI = peer non-suicidal self-injury questionnaire (log transformation); ALEQ = Adolescent Life
Events Questionnaire (ALEQ).

self a tattoo (4.3%). More than one method of NSSI was used by 80.4% of females and
63.4% of males. A Mann-Whitney U test revealed that there was also a significant
gender difference in adolescents’ frequency of NSSI in the past year. Females (Md =
54.93, n = 51) indicated they had engaged in a significantly greater number of NSSI
behaviours than males (Md = 36.01, n = 41) on the FASM, U = 615.50, z = -3.38, p =
.001, r = -0.35.

58
Table 4
Correlations Between the Study Variables (N = 92)
________________________________________________________________________
Scale
1
2
3
4
5
________________________________________________________________________
1. CES-D
2. CRQ

--

.283

.263

.089

.663

--

.291

.001

.298

--

.290

.209

--

.067

3. FASM
4. Peer NSSI
5. ALEQ

--

________________________________________________________________________
Note. CES-D = Center for Epidemiological Studies-Depression Scale (square root transformation); CRQ =
Co-Rumination Questionnaire; FASM = Functional Assessment of Self-Mutilation (log transformation);
Peer NSSI = peer non-suicidal self-injury questionnaire (log transformation); ALEQ = Adolescent Life
Events Questionnaire (ALEQ). NSSI is the total frequency count from section A of the FASM; Peer NSSI
is the total frequency count from the Peer NSSI questionnaire.

The mean age of participants at their first NSSI experience was 11.2 years (SD =
2.8), the youngest being 5 years old. Results showed that of participants who engaged in
NSSI, 29.3% reported their first NSSI experience at age 10 or younger, 32.6% started
between the ages of 11 and 13 years, 18.5% started between 14 and 16 years of age, and
19.6% did not report when they first engaged in NSSI. The majority of self-injurers
stated that they did not think about NSSI before engaging in it (59.8%), they did not
engage in NSSI while taking alcohol or drugs (92.4%), experienced no (23.9%) to little
pain (60.9%%), and did not receive any medical attention for their NSSI (89.1%). No
gender differences were found in age of first NSSI experience or whether these acts
resulted in participants requiring medical attention.

59
Additionally, 68.5% (n = 63) of NSSI participants reported that they had a close peer or
peers who also engaged in NSSI, and of those, 51 reported an approximate frequency for
how many times their peer engaged in different NSSI behaviours. These behaviours,
starting with the most frequent were: picking at wounds (69.8%), self-cutting (50.8%),
biting themselves (39.7%), burning themselves (33.3%), hitting self on purpose (31.7%),
scraping their skin (30.2%), and picking at areas of the body until they bleed (28.6%).
Other methods reported included pulling out hair (15.9%), erasing their skin (19.0%),
inserting objects under their skin or nails (12.7%), giving themselves a tattoo (9.5%), and
other (3.2%).
Analysis Results
Correlation.
Hypothesis 1: Co-Rumination positively correlated with the frequency of NSSI
in adolescents. The relationship between adolescents’ logarithmically transformed selfinjury scores (i.e. log of frequency count from FASM questionnaire) and their corumination scores was examined with a one-tailed Pearson correlation. As hypothesized,
results indicated that there was a significant, positive correlation of small effect size
between adolescents’ level of co-rumination and their frequency of self-injury in the past
year, r = .291, n = 92, p < .01. Co-rumination explained 8.47% of the variance in selfinjury. Adolescents who displayed higher levels of co-rumination reported on the FASM
that they had engaged in self-injury to a greater extent over the past year than those who
displayed lower levels of co-rumination. This relationship did not remain significant for
females r = .122, n = 51, p >.05, and the effect size was small. There was a significant,
positive correlation of small effect size for males r = .283, n = 41, p <.05.

60
Hierarchical multiple regression. Two hierarchical multiple regressions were
completed to examine the final two hypotheses. No violation of the statistical
assumptions of normality, linearity, multicollinearity, homoscedasticity, and independent
errors was detected. Specifically, tolerance and variance inflation factor (VIF) statistics
were examined; tolerance was well above 0.1 and VIF was well below 10 indicating that
the assumption of multicollinerarity was not violated (Field, 2005). The Normal
Probability Plot (P-P) of the Regression Standardized Residual was relatively linear and
normal and the scatterplot was roughly rectangular in distribution; no violations of
linearity, normality, or homoscedasticity were detected. The Durbin-Watson tests had
values around 2, indicating that the residuals were uncorrelated and errors were
independent (Field).
The data was examined for multivariate outliers. There were no multivariate
outliers; the standardized residual was less than positive or negative 3 and Cook’s
distance was less that 1 (Field, 2005). In order to determine whether there was an overly
influential case that would reduce the generalizability of the results, Cook’s distance and
Leverage values were assessed. While the Leverage value for case number 4 was over .2
indicating that it may be an overly influential case that would reduce the generalizability
of the results, the Cook’s distance was less than 1, indicating that this case did not need to
be removed (Field, 2005).
Hypothesis 2: Co-rumination moderates the relationship between depression
and the frequency of NSSI in adolescents. A hierarchical regression analysis was
performed to determine whether co-rumination moderated the relationship between
depression and the frequency of NSSI in adolescents. The criterion variable came from

61
the FASM; it was the frequency of NSSI a participant had engaged in, within the past
year. The predictors included gender and the means of the CESD and CRQ total scores.
Gender was entered as a covariate in block 1 in order to determine the unique variance
that depression and co-rumination account for in adolescent NSSI, above and beyond that
already accounted for by gender. The substantial theoretical and empirical support for
the relationship between depression and self-injury (Andover et al., 2005; Hawton,
Rodham, Evans, & Weatherall, 2002; Nixon, Cloutier, & Aggarawal, 2002; Nock, Joiner,
Gordon, Lloyd-Richardson, & Prinstein, 2006; Klonsky et al., 2003; Ross & Heath, 2002)
suggested that depression would be a more powerful predictor of NSSI than corumination. Additionally, given the exploratory nature of the role of co-rumination with
regard to NSSI, the unique contribution of this variable was sought above and beyond
that of depression. Considering this, depression was entered in block 2 and corumination was entered in block 3. This order of variable entry ensured that elements of
co-rumination were not actually tapping those more appropriately understood as
depression, and resulting in an inflated predictive relationship. The interaction term was
entered in the final block in order to determine the moderating effect of co-rumination on
the frequency of NSSI. Specifically, this allowed the researcher to determine whether the
addition of co-rumination explained additional variance in an individual’s level of NSSI
beyond the main effects of depression.
Gender was entered in block 1, explaining 13.8% of the variance in the frequency
of NSSI. After entry of depression in block 2, the model explained 16.2% of the variance
and after entry of co-rumination in block 3, the model explained 18.3% of the variance.
In block 4, the depression and co-rumination interaction term was entered and results

62
indicated that the overall model significantly predicted frequency of NSSI engagement F
(4, 87) = 5.66, p < .001. However, the second, third, and fourth steps did not contribute
any significant unique variance. In the final model, only gender (β= .30, p <.01) made a
statistically significant unique contributions to the variance of NSSI frequency. Neither
co-rumination (β= .13, p = .21) or depression (β= .17, p = .11) uniquely accounted for
any variance in NSSI frequency once gender was included as a covariate. The analysis
did not provide support for co-rumination as a moderator of depression and NSSI (β= .16,
p = .12); the interaction term did not significantly account for any unique variance in
NSSI. The regression coefficients for all variables, along with bivariate and partial
correlation coefficients are presented in Table 5 and 6, respectively.
Hypothesis 3: Stressful life events moderates the relationship between corumination and the frequency of NSSI in adolescents. A hierarchical regression
analysis was performed to determine whether stressful life events, as measured by the
ALEQ, acted as a moderator of the relationship between co-rumination and the frequency
of NSSI in adolescents. The criterion variable, taken from the FASM, was the frequency
of self-injury in the past year. The predictors included gender and the means of the
ALEQ and CRQ total scores. Gender was entered as a covariate in block 1 in order to
determine the unique variance that stressful life events and co-rumination account for in
adolescent NSSI, above and beyond that already accounted for by gender. Given the
empirical support for the relationship between stressful life events and self-injury (e.g.,
Hankin & Abela, 2011) and the exploratory nature of the role of co-rumination with
regard to NSSI, the unique contribution of co-rumination was sought above and beyond
that of stressful life events. Considering this, stressful life events was entered in block 2

63
Table 5
Hierarchical Regression Analysis for Gender, Depression, Co-Rumination, and
Depression X Co-Rumination Predicting Adolescent NSSI (N = 92)
________________________________________________________________________
Step
R
R2
R2adj
ΔR2
Fchg
p
df1
df2
________________________________________________________________________
Step 1:
Gender

.371

.138

.128

.138

14.356

.000

1

90

Step 2:
Gender
Depression

.402

.162

.143

.024

2.569

.000

2

89

Step 3:
Gender
Depression
Co-Rumination

.428

.206

2.336

.000

3

88

.170

.022

Step 4:
Gender
Depression
Co-Rumination
.454
.206
.170
.023
2.525
.000 4
87
Depression X Co-Rumination
________________________________________________________________________
Note. Depression measured by the Center for Epidemiological Studies-Depression Scale (square root
transformation); Co-Rumination measured by the Co-Rumination Questionnaire; NSSI = non-suicidal selfinjury and was measured by the Functional Assessment of Self-Mutilation (log transformation).

64
Table 6
Coefficients for Final Model in Hierarchical Multiple Regression Analysis for Gender,
Depression, Co-Rumination, and Depression X Co-Rumination Predicting Adolescent
NSSI (N = 92)
________________________________________________________________________
B
β
t
Bivariate r Partial r
Part r
________________________________________________________________________
Gender

.425

.297

2.818*

.371

.289

.269

Depression

.407

.172

1.629

.263

.172

.156

Co-Rumination

.111

.132

1.260

.291

.134

.120

Depression X Co-Rumination .431

.159

1.589

.080

.168

.152

________________________________________________________________________
*p < .05
Note. Depression measured by the Center for Epidemiological Studies-Depression Scale (square root
transformation); Co-Rumination measured by the Co-Rumination Questionnaire; NSSI = non-suicidal selfinjury and was measured by the Functional Assessment of Self-Mutilation (log transformation).

and co-rumination was entered in block 3. This order of variable entry ensured that
elements of co-rumination were not actually tapping those more appropriately understood
as stressful life events, and resulting in an inflated predictive relationship. The
interaction term was entered in the final block in order to determine the moderating effect
of stressful life events on the frequency of NSSI. Specifically, this allowed the researcher
to determine whether the addition of stressful life events explained additional variance in
an individual’s level of NSSI beyond the main effects of co-rumination.
Gender was entered in block 1, explaining 13.8% of the variance in the frequency
of NSSI. After entry of stressful life events scores in block 2, the model explained
15.7% of the variance in the frequency of NSSI. After entry of co-rumination scores (i.e.
centered CRQ total) in block 3, the model explained 17.8% of the variance. In block 4,

65
the co-rumination and stressful life events interaction term was entered and results
indicated that the overall model significantly predicted frequency of NSSI engagement F
(4,87) = 4.82, p = .001. However, the second and third steps did not contribute any
significant unique variance. In the final model, only gender (β = .31, p < .01) made a
statistically significant unique contribution to the variance of NSSI frequency. Corumination (β= .17, p = .13), no longer uniquely accounted for any variance in NSSI
frequency once gender was included as a covariate. The analysis did not provide support
for stressful life events as a moderator of the relationship between co-rumination and
NSSI; the interaction term did not account for a statistically significant amount of unique
variance (β = .06, p = .55). The regression coefficients for all variables, along with
bivariate and partial correlation coefficients are presented in Table 7 and 8, respectively.
Post-Hoc Analyses
Gender, age, and peer NSSI. Past research indicated that gender, age, and peer
NSSI might influence the outcome of this study. These variables were to be included as
predictors in the post hoc analyses of the hierarchical regressions, ultimately only gender
was included due to the following findings. First, this study did not replicate the findings
that depression and co-rumination increased with age (e.g., Nolen- Hoeksema & Girgus,
1994, Rose, 2002; Rose et al., 2007); while this study focused solely on adolescent
subjects, other studies have found an increase in depression and co-rumination over an
age range which included children (i.e., younger than 12). For example, this study looked
at grades 7 through 12, while previous studies looked at grades 3, 5, 7, and 9. When
entered in the first block as a predictor in the hierarchical regressions, it did not
significantly account for any variance in adolescent NSSI.

66
Table 7
Hierarchical Regression Analysis for Gender, Co-Rumination, Stressful Life Events and
Co-Rumination X Stressful Life Events Predicting Adolescent NSSI (N = 92)
________________________________________________________________________
Step
R
R2 R2adj
ΔR2 Fchg
p
df1
df2
________________________________________________________________________
Step 1:
Gender
Step 2:
Gender
Stressful Life Events
Step 3:
Gender
Stressful Life Events
Co-Rumination

.371

.138

.128

.138

14.356

.000

1

90

.397

.157

.138

.020

2.075

.000

2

89

.422

.178

.150

.021

2.239

.001

3

88

Step 4:
Gender
Co-Rumination
Stressful Life Events .426 .182 .144
.003
.358
.001 4
87
Co-rumination X Stressful Life Events
________________________________________________________________________
Note. Co-Rumination measured by the Co-Rumination Questionnaire; Stressful Life Events measured by
the Adolescent Life Events Questionnaire; NSSI = non-suicidal self-injury and was measured by the
Functional Assessment of Self-Mutilation (log transformation).

67
Table 8
Coefficients for Final Model in Hierarchical Multiple Regression Analysis of Gender,
Co-Rumination, Stressful Life Events and Co-Rumination X Stressful Life Events
Predicting Adolescent NSSI (N = 92)
________________________________________________________________________
B
β
t
Bivariate r Partial r
Part r
________________________________________________________________________
Gender

.438

.306

2.920

.371

.299

.283

Stressful Life Events (SLE) .132

.102

.995

.209

.106

.097

Co-Rumination

.139

.165

1.540

.291

.163

.149

SLE X Co-Rumination

.097

.059

.598

-.091

.064

.058

________________________________________________________________________
*p < .05
Note. Co-Rumination measured by the Co-Rumination Questionnaire; Stressful Life Events (SLE)
measured by the Adolescent Life Events Questionnaire; NSSI = non-suicidal self-injury and was measured
by the Functional Assessment of Self-Mutilation (log transformation).

Second, recent research suggested that increases in adolescents’ own selfinjurious behaviour is associated over time with their best friends’ reports of NSSI
(Prinstein et al., 2007). Since only 63 participants had peer NSSI data that could be
included in the analyses, there was not enough power to complete a hierarchical
regression with the original frequency variable. Instead, to control for peer self-injury in
the hierarchical regressions, this continuous variable was changed into a dichotomous
variable. T-tests revealed that there were no differences between the participants who
fully completed the Peer NSSI questionnaire and those who did not on any of the other
variables in this study. As a covariate in the hierarchical regression analyses, the
dichotomous Peer NSSI variable was not found to account for any variance in adolescent
NSSI and so was removed. In making the Peer NSSI variable dichotomous, data
regarding the frequency of peer self-injury was lost and its potential impact greatly

68
minimized. This is highlighted in post-hoc analyses with self-injuring participants who
had fully completed the questionnaire regarding peer NSSI frequency (N = 63); peer
NSSI frequency was significantly correlated with adolescent NSSI frequency, r = .29, p <
.05. This finding suggests that peer NSSI frequency may have significantly accounted for
variance in adolescence NSSI in the hierarchical regressions if all participants had
completed the questionnaire and there was no reason to convert it to a dichotomous
variable.
Gender differences. Due to the gender differences on the majority of the
variables in this study and the different outcomes for each gender for the relationship
between co-rumination and self-injury, further analyses were completed. Correlations
between co-rumination and the other study variables were examined for each gender
separately and exploratory moderation analyses were also completed.
First, upon examining the correlations between co-rumination and other variables
in this study, it became apparent that the effect sizes were larger and significant for males
who self-injured, and small and non-significant for females that self-injured.
Specifically, the correlation between co-rumination and depression had a medium effect
size for males, r = .31, n = 41, p <.05. On the other hand, the correlation for females was
of a very small effect size, r = .08, n = 51, p >.05. While the overall effect size for the
genders together, r = .28, n = 92, p > .01, was of a larger effect size than in previous
research (i.e., .13 and .20; Rose et al., 2007), the difference between genders is
particularly contrary to previous research which has found co-rumination to be predictive
of increases or greater levels of depressive symptoms in females, not males (Rose et al.,
2007).

69
Second, hierarchical regression analyses were used to determine if gender acted as
a moderator of the relationships between the variables in this study. Analyses revealed
that gender only acted as a moderator of the relationship between co-rumination and the
interpersonal independent stressful life events subscale of the ALEQ. Previous studies
have shown that co-rumination is longitudinally associated with an increase in
interpersonal dependent stressors (Hawkin et al 2010). While gender did not moderate
the association between co-rumination and ALEQ total or the interpersonal dependent
subscale, analyses revealed that gender acted as a moderator of the relationship between
co-rumination and the interpersonal independent stressful life events subscale of the
ALEQ. Gender was entered in block 1, explaining 4.1% of the variance in interpersonal
independent stressful life events. After entry of co-rumination scores in block 2, the
model explained 13.9% of the variance. In block 3, the gender and co-rumination
interaction term was entered; the interaction term (β= -.793, p <.05) accounted for an
additional 5.6% of the variance, p < .05. The overall model significantly predicted
interpersonal independent stressful life events F(3, 88) = 7.10, p < .001. A graph of
gender as a moderator of the relationship between co-rumination and stressful life events
is presented in Figure 1. The regression coefficients for all variables, along with bivariate
and partial correlation coefficients are presented in Table 9 and 10, respectively.
The relationship between the interpersonal independent events subscale and corumination for each gender was further examined with one-tailed Pearson correlations.
The correlation between co-rumination and the interpersonal independent events subscale
of the ALEQ was positive and had a large effect size for males, r = .52, n = 41, p <.001.

70

Figure 1. Simple slopes of co-rumination predicting interpersonal independent stressful
life events for males and females.

71
Table 9
Hierarchical Regression Analysis for Co-Rumination, Gender and Co-Rumination X
Gender Predicting Interpersonal Independent Stressful Life Events (N = 92)
________________________________________________________________________
Step
R
R2
R2adj
ΔR2 Fchg
p
df1
df2
________________________________________________________________________
Step 1:
Gender

.202

.041

.030

.041

3.848

.053

1

90

Step 2:
Gender
Co-Rumination

.373

.139

.120

.098

10.142

.002

1

89

Step 3:
Gender
Co-Rumination
.441
.195
.167
.056
6.083
.016
1
88
Gender X Co-Rumination
________________________________________________________________________
Note. Co-Rumination measured by the Co-Rumination Questionnaire; Interpersonal Independent Stressful
Life events was measured by a subscale of the Adolescent Life Events Questionnaire (square root
transformation).

72
Table 10
Coefficients for Final Model in Hierarchical Multiple Regression Analysis of CoRumination, Gender and Co-Rumination X Gender Predicting Interpersonal Independent
Stressful Life Events (N = 92)
________________________________________________________________________
B
β
t
Bivariate r
Partial r
Part r
________________________________________________________________________
Gender

.052

.077

.761

.202

.081

.073

Co-Rumination

.430

1.094

3.368*

.363

.338

.322

-.793 -2.466*

.275

-.254

-.236

Gender X Co-Rumination

-.197

________________________________________________________________________
*p < .05
Note. Co-Rumination measured by the Co-Rumination Questionnaire; Interpersonal Independent Stressful
Life events was measured by a subscale of the Adolescent Life Events Questionnaire (square root
transformation).

73
On the other hand, the correlation for females was of a very small effect size, r = .01, n =
51, p >.05. As well, the mean scores on the interpersonal independent events subscale
(square root transformation) were not significantly different between genders; females (M
= .83, SD = .29) scored similarly to males (M = .69, SD = .37), t(90) = -1.96, p >.05
(two-tailed).
The impact of whether peers engage in self-injury on the relationship
between co-rumination and self-injury. Further post hoc analyses were completed to
determine whether the relationship between co-rumination and self-injury in adolescents
differed depending on whether they had peers who also engaged in self-injury. Increases
in adolescents’ own self-injurious behaviour has been shown to be longitudinally
associated with their best friends’ reports of self-injury over a two year period (Prinstein
et al., 2007). Specifically, if an adolescent has peers who engage in self-injury and also
engages in co-rumination with these peers, they may be socialized to engage in selfinjury as well (Giletta, Burk, Scholte, Engels, & Prinstein, 2013; Heilbron & Prinstein,
2008). Knowing this, it was expected that the correlation between co-rumination and
self-injury would be stronger among those who had peers who self-injured. Since not all
participants completed the peer NSSI questionnaire regarding the frequency of their
peers’ self-injury, there was not enough power to complete a hierarchical regression to
determine whether the frequency of peer NSSI moderated the relationship between corumination and adolescent NSSI. Rather, using the dichotomous variable of Peer NSSI,
participants were divided into those who had peers who engaged in self-injury and those
who did not.

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The relationship between adolescent self-injury and co-rumination scores was reexamined for each group with a one-tailed Pearson correlation. There was a small, nonsignificant correlation between co-rumination and self-injury in those adolescents that
reported they did not have peers who self-injured, r = .06, n = 29, p >.05. For those who
had peers who self-injured, there was a significant, positive correlation of moderate effect
size between the level of co-rumination and the frequency of self-injury in the past year r
= .41, n = 63, p < .001. Co-rumination explained 16.8% of the variance in self-injury in
those who had peers who self-injured. This relationship did not remain significant for
females, r = .24, n = 40, p >.05, and the effect size was small. There was a significant,
positive correlation of large effect size for males r = .55, n = 23, p <.005. A post-hoc
power analysis was conducted using G*Power. Results indicated that a power of .96 was
achieved for the Pearson correlation involving all 63 participants who had peers who
engaged in self-injury, and .45 was achieved for females and of .88 was achieved for
males. Following Cohen’s (1992) recommendations that a power of .8 is ideal to detect
any effects that might exist, the analysis with female participants would require more
participants and further replication to determine whether the effect size remains small and
non-significant.
The next chapter will examine the results of this study within the context of
existing literature on adolescent co-rumination and NSSI. The strengths and limitations
of this study, as well as its implications for NSSI theory and counselling practice will be
discussed.

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CHAPTER V: DISCUSSION
Nonsuicidal self-injury (NSSI) is a pervasive challenge for today’s youth; it is
becoming a part of our communities’ social landscape, with a high lifetime prevalence
rate of 15-20% reported in community samples of adolescents (Favazza, 2009; Heath et
al., 2009). For the purposes of the present study, NSSI was defined as “the deliberate
direct destruction or alteration of body tissue without conscious suicidal intent” (Favazza,
1998, p.260) and is not for religious or cultural purposes (Heilbron & Prinstein, 2008).
This complex phenomenon is undeniably concerning to researchers and clinicians
alike and can be significantly distressing to youth who utilize these behaviours as a
coping strategy. Identifying variables that may contribute to the onset or maintenance of
this behaviour should prove useful in case conceptualization and in developing effective
intervention and prevention approaches. While numerous factors may influence why an
adolescent first engages in and the frequency of their NSSI, this study seeks to provide
empirical evidence to further support and expand research on the impact of peer
relationships on these behaviours. Specifically, this study sought to examine the unique
impact of co-rumination on NSSI in adolescents for the first time. The results for each of
the three hypotheses of the present study, as well as post hoc analyses, are interpreted
below and discussed with respect to relevant research findings in the NSSI literature, as
well as related fields. The clinical implication of the findings for prevention, assessment,
and intervention, as well as the limitations of the study and possible future research are
also discussed.

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Prevalence of NSSI
Based on similar studies, it was expected that between 7 and 16 percent of
community-based adolescent participants would have engaged in NSSI in the past 12
months (Hilt, Nock et al., 2008; Muehlenkamp & Gutierrez, 2004), requiring between
550 and 1300 students to be recruited in order to obtain the required 89 self-injurers for
this study. In the end, of the 770 students who were approached, 234 completed the
survey and 136 of these indicated they had engaged in NSSI in the past year; a very high
overall frequency of 58.1%. Of the 136 who engaged in NSSI in the past year, 92
correctly and fully completed the self-injury questionnaire; 39.3% of the total sample.
An additional 10 (4.3%) reported they had engaged in NSSI prior to the past year;
overall, a lifetime frequency of 62.4% was found in the total sample of participants.
The frequency rates of NSSI in this sample are higher than some studies in
adolescent populations with similar survey techniques (Hilt, Nock et al., 2008;
Muehlenkamp & Gutierrez, 2004), but comparable to others (Hilt, Cha et al,, 2008;
Lloyd-Richardson et al., 2007). Specifically, these comparable studies reported a lifetime
rate of 56% (Hilt, Cha et al., 2008; all female participants), and rates of NSSI engagement
in the past year of 36% (Hilt, Cha, Nolen-Hoeksema, 2008; all female participants) and
46.5% (Lloyd-Richardson et al., 2007). Certain aspects of the methodology used in the
current study may explain why such a high frequency was found. For instance, this study
had a fairly large age range for participation, compared to other adolescent studies.
While Hilt, Nock, et al. (2008) looked at students in grades 6 through 8 and
Muehlenkamp and Gutierrez (2004) at students grades 9 through 12, this study looked at

77
students in grades 7 through 12. This study had 3 and 2 years greater age range,
respectively, than these two similar studies.
In addition to a larger age range, community based studies show that NSSI may
be more common overall in Caucasian, than in African-American and African-Canadian,
adolescents (Lloyd-Richardson et al., 2007; Muehlenkamp & Gutierrez, 2004, 2007; Ross
& Heath, 2002; Whitlock, Eckenrode, et al., 2006). The current study consisted of 80.4%
Caucasian participants which may have contributed to the higher percentage of selfinjurers in this study.
In addition to the broad age range and ethnicity of this sample, the high rates of
self-injury may reflect a self-selected sample due to how the study was presented to
students. While this study did not recruit students by advertising it as one examining
self-injury, which has been the cause of high rates in other studies (Gratz, 2006, Gratz et
al., 2002; Hasking et al., 2008), it did advertise as one examining how adolescents cope
with stress. Similarly, studies which advertised as investigating mental health still had
relatively high rates of NSSI (~20%; Whitlock, Eckenrode, et al., 2006). It is plausible
that some self-selection occurred in the current study, though it was hoped that
advertising as a study on coping with stress would allow for a more anonymous
recruitment of self-injurers and limit any stigmatization about NSSI. Similar to an
individual with mental health concerns becoming interested in a study on mental health or
self-injurers in a study on self-injury; it is possible that an individual who engages in selfinjury would be interested in a study on stress, coping, and peer relationships.
Indeed, self-injurers report a greater number of stressful experiences (Hankin &
Abela, 2011) and difficulty with coping with stress (Chapman, et al., 2006; Favazza,

78
1996; Klonsky, 2007; Nock & Mendes, 2008) and social problem solving (Nock &
Mendes, 2008). In addition to having a greater awareness of or experience with stress
and attempting to cope with stress, they likely have a greater interest in topics related to
stress and wellbeing. Self-injurers also have a greater likelihood of having certain mental
health disorders (e.g., depression, anxiety, BPD; Andover et al., 2005; Hawton al., 2002;
Nixon et al., 2002; Nock et al., 2006; Klonsky et al., 2003; Ross & Heath, 2002) and
possibly due to these concerns would have interest in a study being conducted in the field
of counselling psychology. It is also possible that those teachers who agreed to have the
researcher enter their class may have noticed a greater degree of stress or mental health
concerns in their students and agreed to have their classes participate because of this.
Inflated rates of self-injury may have occurred due to the environment where
participants were recruited. While a lower rate of self-injury is expected from
participants recruited from schools in the community compared to those recruited from
clinical samples (Nixon & Heath, 2009), teachers, other school personnel, and
community counsellors (P. Lorenz, personal communication, May 29, 2012) indicate that
within the last 7 years the frequency of self-injury has increased and remained high
within the community. It may be that this northern BC community has an inflated
number of students who self-injure compared to other communities and further
emphasizes the importance of studying self-injury in community settings, perhaps even
more so in smaller communities, where self-injury may quickly become part of the social
landscape.
Lastly, the operational definition of NSSI in this study was broader than in others
that found a lower rate of NSSI (Hilt, Nock, et al., 2008; Ross & Heath, 2002). The

79
FASM includes a wide range of NSSI behaviours in checklist format and allows for
participants to include an additional “other” behaviour, which would lead to students
reporting a greater frequency of NSSI. The frequency rate of NSSI in this study is similar
to studies which have used the same assessment measure (i.e. FASM; e.g., Hilt, Cha et
al., 2008; Lloyd-Richardson et al., 2007). A greater number of NSSI behaviours on
survey measures have been consistently related to higher rates of reporting (Heath, et al.,
2009); it is likely that participants are primed to report a greater number of methods. In
this study 72.8% utilized more than one method of NSSI which is similar to that found by
Gratz et al., (2012) at 78%. Additionally, researchers have to rely on participants’
understanding of the construct of NSSI, and participants may endorse all behaviours they
have engaged in whether for NSSI purposes or not. In this study a few participants’
reports of NSSI were removed from the data set when written notes on the questionnaires
by participants indicated the behaviour was not NSSI (i.e., accidentally cut hand). These
findings indicate that the questionnaire may not have been understood by some
participants, resulting in false positives in the NSSI data set and thus inflating the
frequency.
In summary, while the present study results of 58.1% are higher than rates
obtained in other recent studies with adolescents in the community (Hilt et al., 2008;
Muehlenkamp & Gutierrez, 2004), it can at least partly be explained by methodological
aspects of the study. Clarifying why the rates are higher in this study is important when
interpreting rates of NSSI among adolescents amongst different studies. Overall, the
lifetime prevalence rate of NSSI in adolescents in the community is considered to be
around 15-20% (Favazza, 2009; Heath et al., 2009); with the current community

80
reporting a much higher rate this is particularly concerning and particularly widespread.
It may be that this sample does not accurately represent the population of self-injuring
adolescents in the community but personal communication with school administration
and counsellors indicate that self-injury is a common form of coping amongst adolescents
in the community. Indeed, consistently higher rates of NSSI are reported in high school
populations (Claes et al., 2009; Laye-Gindhu & Schonert-Reichl, 2005; Ross & Heath,
2002; Zoroglu et al., 2003) and the results of this study further confirm that resources and
attention are best targeted towards this age group and the importance of continuing to
examine the factors associated with NSSI among nonclinical populations in general.
Characteristics of Self-Injuring Participants
While the prevalence of NSSI within the total participant sample was high, certain
characteristics of self-injuring participants were similar to that of other studies which
improves the comparability of the findings in this study. Similar to other community
based studies (Evans et al., 2005; Hawton et al., 2002; Muehlenkamp & Gutierrez, 2007;
Ross & Heath, 2002) this study found a significant gender difference in NSSI prevalence;
females were significantly more likely to engage in NSSI than male participants. While
in clinical samples, females have been found to engage in higher rates of NSSI than
males, this finding is likely due to a difference in help-seeking behaviour and the
inclusion of predominately female behaviours as NSSI (i.e., overdose and medication
abuse without suicidal intent; Briere & Gil, 1998; Rodham et al., 2004). It remains
unclear overall whether there is a significant gender difference in NSSI prevalence in
community samples, as other studies have found no significant gender differences (e.g.,
Jacobsen et al., 2008; Nixon et al., 2002). While this study lends support to those studies

81
which have found a gender difference in community settings, it is possible the gender
differences in this study may be reflective of help-seeking behaviour, rather than a true
difference in NSSI engagement.
The majority of adolescents in this study first engaged in self-injury before the
age of 13. This finding is similar to other studies which have shown that the majority of
individuals who report that they self-injurers often first engaged in the behaviour before
age 15, with a considerable number reporting they had done so before age 12 (e.g.,
Muehlenkamp & Gutierrez, 2007; Ross & Heath, 2002; Sourander et al., 2006).
Research suggests it is difficult to treat NSSI behaviour when it had an early age of onset
and was also overdetermined (i.e. a variety of NSSI methods were used for multiple
functions; Klonsky & Olino, 2008). These findings emphasize the importance of
studying young adolescent NSSI behaviour in the hope of developing effective
prevention and early intervention measures.
In addition, the majority of participants (72.8%) utilized more than one method of
NSSI (similar to Gratz et al., 2012 at 78%). The majority of NSSI participants in the
study (68.5%) also reported that they had a close peer or peers who also engaged in
NSSI, a finding consistent with research on peer socialization effects and contagion of
self-injury in adolescents (Heilbron & Prinstein, 2008; Prinstein et al., 2007) which has
shown that within their close friendships adolescents may be socialized into engaging in
NSSI.
With the majority of recent research focusing on older adolescents (e.g., LloydRichardson et al., 2007; Muehlenkamp & Gutierrez, 2004; Ross & Heath, 2002), and
only recently looking at younger adolescents (e.g., Hilt, Cha et al., 2008; Hilt, Nock, et

82
al., 2008), this study expands upon existing research data by examining both age groups
simultaneously. While this study did not find any age related differences, contrary to
recent findings by Gratz and colleagues (2012) in a comparable age group, this may
partially be due to the difference in ethnicities involved (i.e., this study was 80%
Caucasian, while 67% were Caucasian in Gratz et al., 2012). Specifically, Gratz found
that racial/ethnic background moderated the gender differences in rates of NSSI.
Self-injurers in this study had similar characteristics to those found in other
studies. This is encouraging as this indicates that the results of this study may be
comparable to other populations of a similar ethnic composition. These findings further
support research in adolescent community populations and emphasize the need to further
elucidate what characteristics of adolescents’ social environment contribute to their
learning, and continued use, of NSSI behaviours.
Co-Rumination and NSSI
Co-rumination positively correlated with NSSI in adolescents. This is the first
study to provide preliminary evidence that co-rumination is positively correlated with
nonsuicidal self-injury in adolescents and it also further supports the mounting research
evidence of the impact of social relationships on nonsuicidal self-injury in adolescents
(e.g., Muehlenkamp, Brausch, Quigley, & Whitlock, 2012). In accordance with the
hypotheses, adolescents who displayed higher levels of co-rumination reported that they
had engaged in self-injury to a greater extent over the past year than those who displayed
lower levels of co-rumination. Overall, co-rumination explained 8.47% of the variance in
the frequency of self-injury in the overall sample of self-injurers in this study.

83
The concept of distress tolerance clarifies how co-rumination may exert its
influence on the frequency of nonsuicidal self-injury in adolescents. Studies have shown
that individuals who self-injure report greater subjective levels of experienced affective
distress when faced with stressful events (Najmi et al., 2007; Nock et al., 2008). This
inability to tolerate distress is believed to be an essential facet in the development and
maintenance of self-injury (Chapman et al., 2006; Favazza, 1996; Klonsky, 2007). In
accordance with the Experiential Avoidance Model (EAM; Chapman et al., 2006) and the
automatic negative reinforcement (ANR) function of the Four Function Model (FFM;
Nock & Prinstein, 2004, 2005), it may be that co-rumination exacerbates depressive
symptoms and this drives adolescents to engage in NSSI for relief (Starr and Davila,
2009). It is possible that the spike in cortisol levels recorded by Byrd-Craven and
colleagues (2008; in female participants) following co-rumination may be strong enough
to activate an emotional cascade (e.g., Selby et al., 2008; Selby et al., 2010). According
to the Emotional Cascade Model (ECM), the individual will seek to escape their
increasingly negative affect by engaging in NSSI (e.g., Selby et al., 2008). Alternatively,
findings by Nock and Mendes (2008) suggest that the increase in cortisol following corumination may render a self-injurer incapable of utilizing more adaptive problem solving
and coping strategies when distressed; adolescent self-injurers have been found to be less
able to generate solutions to hypothetical dilemmas after a stress-inducing task and gave
more maladaptive solutions and reported lower self-efficacy for utilizing adaptive
solutions. The repetitive focus on problems in co-rumination may hinder effective
problem solving in self-injurers. As a result, self-injurers may be more likely to engage
in NSSI after co-rumination due to an increase in negative affect or due to the inability to

84
generate, or follow through on, any adaptive alternative solutions to difficulties. Further
research is clearly needed though, as the research on co-rumination and cortisol was
completed with female participants and cannot be generalized to male participants.
Additionally, the ECM model has only started to be evaluated in research, and only
recently among self-injurers (Selby et al., 2010).
Research on the related construct rumination, also suggests why co-rumination is
positively correlated with self-injury. It may be that co-rumination, characterized by its
lack of constructive problem solving, focus on the negative event and associated negative
affect, and its link to elevated depressive symptoms (e.g., Calmes & Roberts, 2008; Rose,
2002), acts similarly to rumination. Co-rumination may intensify the impact of negative
affect on adolescents’ cognitive processing and hinder the use of effective, problem
solving behaviours that could alleviate depressive symptoms; much like rumination has
been proposed to do (Nolen-Hoeksema 1987, 1991). Doing so, co-rumination would
exacerbate depressive symptoms in adolescents who have a tendency to co-ruminate
about their problems with their peers and increase the likelihood that they would engage
in unhealthy, dysregulated behaviours like NSSI to cope with these distressing feelings.
While co-rumination is hypothesized to act similarly to rumination (Calmes & Roberts,
2008; Rose, 2002; Rose et al., 2007), it would be important in future research to include
rumination in analyses in order to ensure a more stringent test for the role of corumination; future research should examine whether co-rumination uniquely predicts
NSSI behaviour even after controlling for rumination.
Additionally, research on peer socialization also suggests how co-rumination may
influence adolescent NSSI. Co-rumination may be an indirect form of peer socialization;

85
it may be that an adolescent’s engagement in NSSI is influenced indirectly through
another characteristic of their friends (Brechwalk & Prinstein, 2011). When adolescents
are exposed to certain characteristics of their friends, this creates an environment that
puts the adolescents’ own development at risk. As research has shown, co-rumination
increases stress in the relational partners (Byrd-Craven et al., 2008), which increases the
likelihood that they will experience greater depressive symptoms (i.e. direct form of peer
influence related to depression; Van Zalk et al., 2010) and will engage in dysregulated
behaviours such as NSSI (Giletta, Burk, Scholte, Engels, & Prinstein, 2013). This
indirect form of NSSI socialization was supported in recent research (Giletta et al., 2013),
which found that “friends’ depressive symptoms had an additive effect on adolescents’
NSSI above adolescents’ depressive symptoms. Thus, having friends with depressive
symptoms may be particularly harmful for those adolescents with underlying
predispositions to endorse NSSI, for instance adolescents having difficulties in regulating
their emotions (Nock & Prinstein, 2004)” (p.21).
The relationship between co-rumination and self-injury in male participants.
Contrary to research which has shown that co-rumination has a greater negative impact
on females than males in regards to emotional adjustment (i.e., symptoms of anxiety and
depression, Rose et al., 2007), this study indicates that co-rumination may influence selfinjurious behaviours in males to a greater degree than in females. When genders were
examined separately, the positive correlation between co-rumination and NSSI frequency
did not remain significant for females and the effect size was small, with co-rumination
explaining 1.49% of the variance in frequency of self-injury in females. The effect size
for males was also small (approaching medium), with co-rumination explaining 8.00% of

86
the variance in self-injury frequency in males. It may be that the effect size would
increase with a larger sample size.
Beyond the possible explanations previously mentioned for how co-rumination
may influence self-injury, this result suggests that there may be another factor influencing
this relationship, specific to males. Further expanding on indirect peer socialization, it
may be that adolescent male NSSI behaviour is influenced by other related psychological
characteristics of their friends, such as impulsivity. Recent research has shown that
impulsivity among male adolescents’ friends is associated with increases in male
adolescents’ own NSSI (Giletta, Burk, Scholte, Engels, & Prinstein, 2013). While corumination has been tied to greater friendship quality (Rose et al., 2007) in males, it may
be that co-rumination in male friendships creates an environment which encourages them
to act impulsively (i.e. engage in NSSI) in response to distress, rather than focusing on
effective problem solving (Nock & Mendes, 2008).
Co-rumination and stressful life events in male self-injurers. Another result
from post-hoc analyses provides a different hypothesis for the stronger effect size of the
relationship between co-rumination and self-injury among male participants. Among
male self-injurers there was a large effect size for the relationship between co-rumination
and interpersonal independent stressful life events. In fact, gender acted as a moderator
variable of the relationship between co-rumination and the interpersonal independent
stressful life events subscale of the ALEQ. While previous studies have shown that corumination is longitudinally associated with an increase in interpersonal dependent
stressors (Hawkin et al., 2010), it is unlikely that co-rumination would actually increase
the number of interpersonal independent stressors that occur. Perhaps, among male self-

87
injurers, the more they engage in co-rumination, the more stressors become a salient part
of their experience (Rose et al., 2007). It is possible that when co-rumination increases
the salience of any stressors they experience this will increase their depressive symptoms;
stressors have been tied to higher depressive symptoms (e.g., Hankin et al., 2007). It is
possible that in amplifying the stressors experienced this would chip away at individuals’
ability to effectively cope with and problem-solve the stressors that are accumulating in
their lives (Hankin et al., 2010). Due to self-injurers’ difficulty tolerating distress (e.g.,
Klonsky, 2007), they would likely engage in self-injury to alleviate their increased
feelings of depression (Klonsky, 2007). This correlates with past research which has
found that more stressful life events significantly differentiated adolescents who engaged
in NSSI from those who did not (Hankin & Abela, 2011) and NSSI is most frequently
carried out in order to diminish affective distress (Nock et al., 2006).
Co-rumination, peer self-injury, and adolescent self-injury. Evaluation in
post-hoc analyses further highlights the role of socialization processes in explaining the
relationship between co-rumination and the frequency of self-injury in adolescents,
specifically among male participants in this study. The relationship between adolescent
self-injury and co-rumination scores was re-examined for those who had peers who
engaged in self-injury and those who did not. While there was a small, non-significant
correlation between co-rumination and self-injury in those adolescents that reported they
did not have peers who self-injured, there was a significant, positive correlation of
moderate effect size between adolescents’ level of co-rumination and their frequency of
self-injury in the past year for those who had peers who self-injured. Further, when
genders were examined separately this relationship did not remain significant for females,

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and the effect size was small, but there was a significant, positive correlation of large
effect size for males. While results must be interpreted with caution as there was not
enough power to detect effects among female participants, they further suggest that peer
socialization may also be impacting adolescent engagement in self-injury, particularly
among males. That is, increases in adolescents’ own NSSI behaviour has been shown to
be longitudinally associated with their best friends’ reports of NSSI over a two year
period (Prinstein et al., 2007). Specifically, if an adolescent has peers who engage in
self-injury and also engages in co-rumination with these peers, they may be socialized to
engage in self-injury as well (Giletta, Burk, Scholte, Engels, & Prinstein, 2013; Heilbron
& Prinstein, 2008). It could be direct socialization, whereby an adolescent’s engagement
in self-injury is directly influenced by their peers’ engagement in NSSI (Prinstein et al.,
2010), though this finding was solely for adolescent females self-injurers. On the other
hand, as previously discussed, it could be indirect socialization, with an adolescent
engaging in NSSI like his/her peers due to “related psychological characteristics,
dispositions, attitudes, or values of his/her friends” (p.8; Giletta et al., 2013).
Longitudinal research is needed to determine which processes may be influencing this
relationship and the mechanisms involved.
Co-rumination as moderator variable. Hypotheses two and three were not
supported; co-rumination failed to moderate the relationship between depression and
NSSI frequency, and stressful life events failed to moderate the relationship between corumination and NSSI frequency. Although contrary to the study’s hypotheses, other
results from this study suggest a possible explanation. There were significant gender
differences in the previously reviewed results; results were significant and had greater

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effect sizes for male self-injurers. With only 41 male self-injurers and 51 female selfinjurers the moderation analyses could not be completed separately for each gender due
to a lack of statistical power. From the results of hypothesis 1, it is possible that with
enough male participants the moderation analyses would be significant. Further research
is obviously needed to determine whether this would be the case. Additionally, this study
solely utilized the frequency of self-injury and did not take into account the function of
the self-injury for each individual. While primarily used for affect regulation (e.g.,
Klonsky, 2007) the reasons an individual engages in NSSI may vary over time and
context (Suyemoto, 1998) making it difficult to discern the factors that contribute to the
initiation and maintenance of this behaviour. It would be important to replicate this
study, and further elucidate the relationship between co-rumination and NSSI in
adolescents for different functions of self-injury. The impact of co-rumination may differ
depending on the function of self-injury primarily endorsed. It may be that co-rumination
has a higher correlation with the social functions of NSSI. Co-rumination is a social
process and other researchers have correlated social concerns with the endorsement of
social functions of NSSI (Nock & Prinstein, 2005); peer communication and rumination
have been identified as moderators between social functions (i.e., social negative
reinforcement; SNR and social positive reinforcement; SPR) and interpersonal distress
and between automatic positive reinforcement (APR) and internal distress, respectively
(Hilt, Cha, et al., 2008). These results were only found in female participants though, and
need to be further studied in male self-injurers. It is possible however that co-rumination,
which has features of peer communication and rumination, would also act as a moderator
between social functions and interpersonal distress and between APR and internal

90
distress. It would be interesting if the strength of the effect size increased among females
for the social function of self-injury, as females have been shown to experience more
stressors in interpersonal contexts and react more strongly to these stressors in the form
of depression (Hankin et al., 2007). The impact of co-rumination on self-injury in female
adolescents may be more specific to these factors.
Another avenue of research would involve looking at the distinct self-injurer
subgroups that can be “identified on the basis of NSSI method, function, and contextual
features” (Klonsky & Olino, 2008, p.22). While evaluating the differing levels of corumination within these four distinct subgroups is beyond the scope of this study, corumination may have a differing effect on different subgroups of self-injurers. For
instance, two of the four groups identified by Klonsky and Olino exhibited increased
clinical symptomology, earlier onset, and deliberate (rather than experimental)
engagement in self-injury for multiple functions (i.e., not solely for affect regulation).
Other studies distinguish between single versus repetitive (e.g., Muehlenkamp, Brausch,
Quigley, & Whitlock, 2012) self-injurers or those who engage in Low NSSI versus High
NSSI (e.g., MacLaren & Best, 2010). Dividing self-injurers in this manner has revealed
that those in the repetitive or High NSSI groups exhibit elevated clinical concerns (e.g.,
alcohol and drug abuse, disordered eating, lower perceived social support, heightened
psychiatric concerns; Klonsky & Oliono, 2008; MacLaren & Best, 2010; Muehlenkamp
et al., 2012). These findings suggest that co-rumination, which has been found to be
positively correlated with an increase in affective distress (Rose, 2002; Rose et al., 2007;
Starr & Davila, 2009) and may exacerbate depressive symptoms in dysphoric individuals
(i.e. those individuals who engage in a higher frequency of self-injury; Starr and Davila,

91
2009), may be present at a greater level in those who engage in repetitive, or a higher
frequency of self-injury.
Alternatively, the finding that co-rumination did not moderate the relationships as
hypothesized suggests that co-rumination may be involved in a more distal manner to
self-injury. For example, it is possible that co-rumination would moderate the
relationship between stressors and depression and in this fashion, akin to indirect
socialization effects, worsen depression and in turn contribute to an increased likelihood
that an individual would engage in self-injury for symptom relief. Co-rumination has
been found to precede depression; in fact this relationship appears to be transactional in
nature with the effect of co-rumination building and accumulating over time (Hankin et
al., 2010). Co-rumination has been found to have a similar interaction with stressors; corumination predicts interpersonal stressors and these stressors in turn predict an increase
in co-rumination (Hankin et al., 2010). This transactional relationship “likely amplifies
the stressors experienced and chips away at individuals’ ability to effectively cope with
and problem solve the stressors that are accumulating in their lives” (p.230, Hankin et al.,
2010). These findings confirm the importance of longitudinal research examining factors
that may increase adolescent vulnerability to engaging in self-injurious behaviour.
Limitations
While the findings of the present study represent a valuable addition to the
literature on adolescent NSSI, they need to be interpreted with certain limitations in mind.
This investigation was cross-sectional in nature limiting the ability to make causal
inferences. While the correlational results of this study are appropriate for the initial
exploration of the relationship between co-rumination and NSSI in adolescents, future

92
research using longitudinal designs would help determine causality. Furthermore, a
quasi-experimental design would help researchers determine causal relationships
providing further understanding regarding the effects of co-rumination on NSSI.
The use of self-report measures presents some potential problems such as social
desirability. Although most researchers investigating NSSI behavior use self-report
measures (e.g., Armey & Crowther, 2008; Gratz et al., 2011; Hankin & Abela, 2011;
Nock & Prinstein, 2004; Ross & Heath, 2002; Selby et al., 2010), social desirability
could lead to underreporting of this behaviour. It is unlikely that underreporting occurred
in this study, considering the high rate of NSSI obtained. With NSSI becoming part of
our social landscape (Favazza, 2009) it may be that adolescents are comfortable in
reporting their self-injurious behaviour. It is possible that participants may have
responded carelessly; the validity of the data depends upon the honesty of the respondent
even though statistical analyses can be of some help (Mertens, 2005). In addition, the
self-report measures of co-rumination used in the present research might not have
adequately distinguished between co-rumination and more positive forms of selfdisclosure and relationship satisfaction. Observational data in future research may prove
useful in separating co-rumination, self-disclosure, and relationship satisfaction.
Using a self-report measure for NSSI also means that the research has to rely on
participants’ understanding of the construct of NSSI as described in the FASM;
participants may endorse every behaviour they have engaged in whether for NSSI
purposes or not and this will affect the validity of our findings as everyone who selfreports as a self-injurer may in fact not be. While not feasible for this study, it has been
recommended that follow-up interviews be used to assist in clarifying participants’

93
understanding of whether the tissue damage was indeed NSSI or due to other behaviours
(e.g., drug use; Heath et al., 2009). While a self-report measure is insufficient to properly
explore the nature and meaning of NSSI behaviours, in order to preserve anonymity and
obtain an unbiased sample, the self-report method was nevertheless used. Knowing that
questionnaires without follow-up interviews inflate NSSI reporting (Ross & Heath,
2002), results will be interpreted with this caveat in mind.
In addition, it was noted in this study that participants had difficulty estimating
the number of times they had engaged in a particular NSSI behaviour; some participants
instead wrote comments like “a lot” or “many” or “all the time” for frequency rather than
a number resulting in their data being unusable in this study. This was particularly noted
in younger grades, though it may be that other participants who left the frequency blank,
and also had their data removed from the study, also decided not to provide an answer
due to the difficulty in estimating their frequency of self-injurious behaviour in the past
year. It is possible, that the participants who did not complete the questionnaires properly
and had their data removed from the study were in some way different from those who
completed the study; this limits the generalizability of the results of this study. A recent
study using the FASM (Guan, Fox, & Prinstein, 2012) provided anchors (i.e., 1 = Never,
2 = 1-2 times, 3 = 3-5 times, 4 = 6-9 times, 5 = 10 or more times) for this scale to aid in
more accurate reporting. This would likely have made the questionnaire more easily
answered by participants.
In addition, as outlined by Heilbron and Prinstein (2008) the source of our data
needs to be considered. This study asks participants to report on their peers’ NSSI
behaviour, essentially assuming that participants’ assumption of what their friends are

94
doing is as important as what their friends are actually doing. In response, it has been
argued that adolescents are more influenced by their own perceptions than by their
friends’ actual behaviour (Bauman & Fisher, 1986) and adolescents’ own behaviour is
more strongly correlated to their perception of their friends’ behaviour than their friends’
actual behaviour (see Kandel, 1996, for a review).
This study is also limited in focusing solely on one individual’s perception and
report of co-rumination. Given that the interpersonal and emotional impact of this
process may vary between individuals within the same dyad, it would be important to
examine co-rumination from the perspective of both members of the relationship dyad in
future research. Even further, future research may want to examine co-rumination
behaviour among groups involving more than two individuals.
The cross-sectional design limits the conclusions that can be drawn about the role
of co-rumination in the development and maintenance of NSSI. Findings were not based
on longitudinal data, and as such do not merit statements regarding causality. Also,
findings with regard to gender related differences should be interpreted with caution.
Specifically, it is not clear whether the difference in the relationship between corumination and self-injury between genders is due to actual gender differences and can be
generalized to other populations. Further study to confirm these findings is required.
Characteristics of this sample of participants also limit the generalizability of
these results. The overall participant sample comprised of 234 volunteers, of the possible
770 given consent forms. It may be that there are differences between those which
decided to complete the study and those who did not. In addition, participants were

95
predominately middle class and Caucasian, further limiting the generalizability of the
results.
Strengths and Contribution
Despite these limitations, this study also has strengths and makes a valuable
contribution to the existing literature on nonsuicidal self-injury in adolescents in the
community. While research has started to show the importance of adolescents’
interpersonal experiences as relevant for understanding and treating NSSI (e.g.,
Muehlenkamp et al., 2012, Prinstein et al., 2009), this study contributes to the literature in
important, novel ways, specifically regarding the unique role of co-rumination. The
association between these two constructs had not been investigated previously and this is
the first study to provide preliminary evidence that co-rumination is positively correlated
with nonsuicidal self-injury in adolescents.
In addition to uniting research on self-injury and co-rumination in adolescents, a
valuable contribution of this study was the inclusion of male adolescent participants.
Research on both NSSI and co-rumination has been completed primarily with female
participants because research has shown that they are at greater risk for internalizing
emotional problems starting in adolescence (e.g., Hankin & Abramson, 1999; Hankin &
Abramson, 2001; Rose et al., 2007) and suggests that they have higher rates of self-injury
(Nock, 2009). As a result, researchers may be overlooking the distress experienced by
adolescent males, particularly those who engage in self-injury. In fact, this study
suggests that certain processes, specifically co-rumination, may in fact lead to greater
vulnerability in males who self-injure, than in females who self-injure. This study
indicates that co-rumination is also involved in male affective distress (i.e., depressive

96
symptoms) and NSSI. Specifically, it appears that adolescent male self-injurers are more
likely to have elevated symptoms of depression, higher levels of stressors, and a
heightened frequency of self-injury, the more they engage in co-rumination. If the
findings of this study hold in replication, it would further support the need to study selfinjury and co-rumination in males, not solely in females. In addition, despite the
significant gender differences in this study, it is important to remember that there was a
large degree of variability within gender; therefore, identifying other individual
difference characteristics related to co-rumination and self-injury will also be important.
While this study does not elucidate how co-rumination impacts self-injurious
behaviour, other results from this study and past research suggest that co-rumination may
intensify the negative affect and the salience of stressors that adolescents experience.
This, combined with self-injurers’ difficulty tolerating distress (e.g., Klonsky, 2007) and
inability to generate or follow through on adaptive coping strategies (Nock & Mendes,
2008) would likely lead them to engage in self-injury to alleviate their increased feelings
of depression (Klonsky, 2007).
It is also possible that co-rumination impacts self-injury frequency through direct
or indirect socialization. Through direct socialization, whereby co-rumination with peers
provides an opportunity for an adolescent to learn about NSSI and have their use of NSSI
as a coping strategy reinforced by their peers’ mutual engagement in NSSI (Prinstein et
al., 2010). Indirectly, co-rumination may create an environment which increases stress in
the relational partners (Byrd-Craven et al, 2008; Giletta et al., 2013) thus increasing
feelings of depression, or promotes male self-injurers to act impulsively in response to
distress, rather than focusing on effective problem solving (Nock & Mendes, 2008). In

97
turn, these changes would increase the likelihood of engaging in other emotionally
dysregulated behaviours, such as NSSI (Giletta et al., 2013).
Longitudinal research is needed to determine which processes may be influencing
the relationship between co-rumination and self-injury and the mechanisms involved.
Research is also needed to replicate these results and elucidate why male self-injurers
appear to be more vulnerable to the influence of co-rumination than female self-injurers,
especially with past research showing co-rumination to be more deleterious for females
(i.e., greater risk of depression and anxiety; Rose et al., 2007).
Clinical Implications
In addition to advancing knowledge in the field, the results of this study have the
potential to improve clinical practice. While it is not known how co-rumination impacts
the frequency of NSSI, results suggest that adolescents, especially males, who self-injure
may engage in NSSI to a greater degree the more they engage in co-rumination within
their friendships. These results suggest several factors that might lead to more
comprehensive and effective intervention, prevention, and treatment plans for counsellors
working with adolescents who engage in nonsuicidal self-injury.
Co-rumination is a socially rewarding process, associated with greater feelings of
satisfaction in friendships (Calmes & Roberts, 2008; Rose 2002; Rose et al., 2007; Starr
& Davila, 2009). Nevertheless, as this study and others (e.g., Calmes & Roberts, 2008;
Rose, 2002) have shown, co-rumination not only fails to defend against distress but may
actually be involved in increasing risk for affective distress and using dysregulated
behaviours like NSSI. Knowing this, assessment of co-rumination among dysphoric
individuals such as self-injurers is recommended as it may lead to increased distress and a

98
greater likelihood they will engage in self-injury. It would be particularly important to
assess male self-injurers as they may be particularly vulnerable to the detrimental effect
of this style of communication.
Certainly, adolescents should not be discouraged from talking with their friends.
Rather, peers are an important social support in adolescence (Muehlenkamp et al., 2012)
and this research suggests that counsellors should increase adolescents’ awareness of the
potential risk of negative and ruminative talk about problems with their peers. It should
be noted too that youth at risk for problems associated with co-rumination may be
overlooked precisely because they do have seemingly positive, open communication with
peers. It would be important for counsellors to evaluate the interaction styles of their
clients’ friendships to determine whether they may be high in co-rumination. Possible
interventions in such cases might include re-directing adolescents to more constructive
communication through problem-solving training and practicing more effective and
adaptive ways of communicating and self-disclosure with peers.
Results also suggest that co-rumination may have a possible influence through
direct socialization. For instance, co-rumination may provide an opportunity for
adolescents to learn about self-injury from their peers, or have it reinforced by peers’
mutual engagement in NSSI (Prinstein et al., 2010). The influence of peer self-injury and
possible contagion should be carefully considered in treatment, as those adolescents who
have peers who engage in self-injury are particularly at risk to engage in these behaviours
as well (Prinstein et al., 2010). This study suggests that male self-injurers who engage in
higher levels of co-rumination and also have peers who self-injure are at particular risk
for higher levels of self-injury.

99
In addition, findings in this study and others suggest that co-rumination may be
involved in increasing the salience of stressors, increasing the number of stressors
encountered over time, and in increasing the intensity of negative affect (Hankin et al.,
2010). Knowing this, and that self-injurers’ have difficulty tolerating distress (e.g.,
Klonsky, 2007) and effectively generating or following through on adaptive coping
strategies (Nock & Mendes, 2008) in response to stressors, suggests further interventions.
The use of interventions that address how adolescents respond to stress, cope with
distress and regulate their affect (i.e., whether they ruminate with others) may be
particularly helpful. Certain treatment modalities such as Dialectical Behaviour Therapy
(DBT; Linehan, 1993) have particular utility. DBT has been adapted for work with
adolescents (e.g., Miller, Rathus, & Linehan, 2007); it focuses on strategies and tools that
aid self-injurers in tolerating distress and regulating their emotions and teaches effective
problem solving skills. Given the prevalence of self-injury in the community, these skill
deficits may also be addressed by school wide programs that teach healthy and adaptive
ways of coping and emotion regulation and would allow for intervention without
stigmatization.
Prevention and intervention efforts may be particularly challenging given the
subtle nature of co-rumination and that its association with positive relationship quality
may be reinforcing. Results from this study suggest that co-rumination is linked to the
frequency of self-injury in adolescent self-injurers and highlight the need to adopt a more
careful evaluation of the role of friendships and social support in the lives of adolescents
who self-injure. While further research is needed to elucidate how this relationship
functions and to determine causality, it emphasizes the importance of peer relationships

100
on adolescents’ emotional development and choice of coping strategies. This study also
highlights areas that clinicians and school personnel alike can target in hopes of
facilitating healthy interactions with peers and maximizing the emotional health of
adolescents who self-injure.

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124
Appendix A
Introduction and Overview of Study
Hello. My name is Sarah Lloyd and I’m a student in the Counselling Psychology
program at Trinity Western University in Langley. I am conducting a study with my
supervisors, Dr. Joan Kimball and Dr. Derrick Klaassen, on how friendships influence
how teens cope with stress. I would very much appreciate your participation.
Specifically, this study will investigate the relationship between how you talk about your
problems and feelings with your friends and how you cope with stress. It will also look
at the link between how you cope with stress and your feelings of depression.
For this study, it is required that your parents sign a consent form for you to participate.
This consent form needs to be returned by___. Your participation is optional and it will
have no impact on your grade in this class. If you participate in this study you will be
entered in a draw for 1 of 3 $50.00 gift certificates for iTunes.
In __ weeks, once your parental consent forms have been received, I will return to hand
out the questionnaires which you will complete during class. The questionnaires will
take approximately 40 minutes to complete and are completely confidential. The
questionnaires used in this study have been used in other studies. The questionnaires ask
about stress, the different ways that you cope with stress and about feelings of depression.
They also ask about the way you discuss your problems with your friends and how often
you do this.
Any questions will be answered at this time.

125
Appendix B

126

127

128
Appendix C
Review of Study, Consent, Confidentiality, Risk and Benefits
Assent forms and questionnaire packages will be passed out while delivering speech.
Questionnaires will be completed during class time.
This study will look at how friendships influence how teens cope with stress. Friendships
are very important in our lives and when stressed we may use a number of different
behaviours to cope (e.g., listen to music, play videogames, talk to someone, eat,
physically hurt themselves on purpose, or smoke). Specifically, this study will
investigate the relationship between how you talk about your problems and feelings with
your friends and how you cope with stress. It will also look at the link between how you
cope with stress and your feelings of depression.
The questionnaires will take approximately 30-40 minutes to complete and are
completely confidential. The questionnaires used in this study have been used in other
studies. The questionnaires ask about stress, the different ways that you cope with stress
and about feelings of depression. They also ask about the way you discuss your problems
with your friends and how often you do this.
The risks in participating in this study are minimal. There is a possibility that you may
find answering some of the questions uncomfortable or upsetting due to their personal
nature. Taking part in the study is completely voluntary. You may choose not to answer
a question if it makes you uncomfortable and you are also free to withdraw from the
study at any time. The school counsellors are aware of this research study and are
available to talk to you should you feel distressed after participating in this study. A list
of counselling agencies will also be provided.
In order to participate, your parent/guardian must have signed the consent form. The first
page is an assent form. Please read it carefully and sign it if you agree to participate. At
the end of the study you will be given another copy of the assent form to keep. Your
names and consent forms will be stored separately from your responses and only the
researchers will have access to this confidential information. Once you have signed the
assent form, please fill out the questionnaire package silently and turn it over when you
have finished. It is very important that there be no talking and that the questions be filled
out individually. If you have questions raise your hand and I will come to you.
Your participation is optional and it will have no impact on your grade in this class. If
you choose not to participate, just hold on to it until everyone is done and then hand it in
blank. There are activity pages at the end of the questionnaire package that you can do
while waiting or you can quietly read or work on a class assignment. If you participate in
this study you will be entered in a draw for 1 of 3 $50.00 gift certificates for iTunes. If
you decide to withdrawal you will still be entered in the prize draw.
Thank you very much for you time.

129
Appendix D

130
Appendix E
Follow-Up
Thank you for participating in this survey! If you would like to receive a summary of the
research findings once this study is complete please fill out the form below. Your
signature below indicates that you agree to have the researcher retain your name and
contact information until a copy of the research findings has been sent to you and that
you understand that this information will be kept separate from your survey answers.
Name (please print):_______________________________________________________

E-mail or Mailing Address (please print):
________________________________________________________________________

131
Appendix F
Peer Relationships and Coping with Stress in Teens: Debriefing Information Sheet
Dear Participant,
Thank you for taking part in our survey. The information you provided will help us to
understand the relationship between how you talk about your problems and feelings with
your friends and how you cope with stress. If you wish to withdrawal from the study
now that you have completed the questions, let the researcher know and your survey
package will be removed from the study.
As a thank you for your time and cooperation, you will be entered in our draw for 1 of 3
$50.00 gift certificates for iTunes and your school principal will contact you if you win.
Some of the questions that you were asked to fill out deal with very personal and
sensitive issues. For this reason, the school counsellors are aware of this research study
and are available to talk to you should you feel distressed. A list of counselling agencies
is also provided below. Please talk to your school counsellor or make use of the
resources below should you require any additional support. Do not hesitate to call
our research team if you have any questions or concerns.
Thank you,
Sarah Lloyd, Dr. Derrick Klaassen, and Dr. Joan Kimball
Counselling Resources
Below is a list of different counselling agencies in Fort St. John, if you or your parents
would like to make your own arrangements.



Ministry of Children and Family Development - Child and Youth Mental Health:
(250) 787-3344
North Peace Community Resources Society: (250) 785-6021

This list is not complete and you are welcome to search for your own counsellor instead,
if you prefer. Good places to begin such a search include:
 BC Association of Clinical Counselors (http://www.bc-counsellors.org/memgate.htm)
 BC Association for Marriage and Family Therapy
(http://www.bcamft.bc.ca/consumer-info/choose-therapist.htm)
 Canadian Counselling Association (http://www.ccacc.ca/cccdir/php)

132
Appendix G
Demographic Information
1. How old are you?______________________________
2. Gender (please circle): male

female

3. Grade level at school:___________________________
4. Ethnicity (please circle):

5. Where I live (please circle):

Aboriginal Person
Asian
Black
Latino
White
Mixed Ethnicity
Other

Rented House/Duplex
Rented Apartment
Own House/Duplex
Group Home
Foster Home
Other

6. Who I live with (please circle):

7. Parent’s marital status (please circle):

Live alone
Live with single parent
Live with two parents
Live with non relatives
Live with relatives
Other

Married
Separated
Divorced
Never married
Widowed
Not known

8. Mother’s current work (please circle): 9. Father’s current work (please circle):
Working full time
Working part time
Home duties
Not working
Student
Retired
Other
Not Known

Working full time
Working part time
Home duties
Not working
Student
Retired
Other
Not known

133
Appendix H
Center for Epidemiologic Studies Depression Scale (CES-D)
Below is a list of the ways you might have felt or behaved. Please tell me how often you
have felt this way during the past week. (please √ or X in the appropriate box)
During the Past Week
Rarely or
none of the
time
(less than 1
day )

1. I was bothered by things that
usually don’t bother me.
2. I did not feel like eating; my
appetite was poor.
3. I felt that I could not shake
off the blues even with help
from my family or friends.
4. I felt I was just as good as
other
people.
5. I had trouble keeping my
mind on what I was doing.
6. I felt depressed.
7. I felt that everything I did
was an effort.
8. I felt hopeful about the
future.
9. I thought my life had been a
failure.
10. I felt fearful.
11. My sleep was restless.
12. I was happy.
13. I talked less than usual.
14. I felt lonely.

Some or a
little of the
time
(1-2 days)

Occasionally
or
a moderate
amount of
time
(3-4 days)

Most or all
of the time
(5-7 days)

134
15. People were unfriendly.
16. I enjoyed life.
17. I had crying spells.
18. I felt sad.
19. I felt that people disliked
me.
20. I could not get “going.”

CESD Scoring: zero for answers in the first column, 1 for answers in the second column,
2 for answers in the third column, 3 for answers in the fourth column. The scoring of
positive items (i.e. 4, 8, 12, and 16) is reversed. Possible range of scores is zero to 60,
with the higher scores indicating the presence of more depressive symptoms. Weissman et
al. (1980), the developers of the CESD, have used the cutoff score of 15 as being suggestive
of depressive symptoms in children and adolescents. That is, scores over 15 can be indicative
of significant levels of depressive symptoms.

135
Appendix I
Co-Rumination Questionnaire

When We Talk About Our Problems
Think about the way you usually are with your best or closest friends
who are girls if you are a girl or who are boys if you are a boy and circle
the number for each of the following statements that best describes you.
1. We spend most of our time together talking about problems that my friend or I
have.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

2. If one of us has a problem, we will talk about the problem rather than talking
about something else or doing something else.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

3. After my friend tells me about a problem, I always try to get my friend to talk
more about it later.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

4. When I have a problem, my friend always tries really hard to keep me talking
about it.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

5. When one of us has a problem, we talk to each other about it for a long time.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

6. When we see each other, if one of us has a problem, we will talk about the
problem even if we had planned to do something else together.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

7. When my friend has a problem, I always try to get my friend to tell me every
detail about what happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

8. After I've told my friend about a problem, my friend always tries to get me to talk
more about it later.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

136

9. We talk about problems that my friend or I are having almost every time we see
each other.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

10. If one of us has a problem, we will spend our time together talking about it, no
matter what else we could do instead.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

11. When my friend has a problem, I always try really hard to keep my friend
talking about it.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

12. When I have a problem, my friend always tries to get me to tell every detail
about what happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

******************************************************
******************************************************
When we talk about a problem that one of us has....
1. ... we will keep talking even after we both know all of the details about what
happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

2. ... we talk for a long time trying to figure out all of the different reasons why the
problem might have happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

3. ... we try to figure out every one of the bad things that might happen because of
the
problem.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

4. ... we spend a lot of time trying to figure out parts of the problem that we can't
understand.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

5. ... we talk a lot about how bad the person with the problem feels.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

137

6. ... we'll talk about every part of the problem over and over.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

7. ... we talk a lot about the problem in order to understand why it happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

8. ... we talk a lot about all of the different bad things that might happen because of
the problem.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

9. ... we talk a lot about parts of the problem that don't make sense to us.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

10. ... we talk for a long time about how upset is has made one of us with the
problem.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

11. ... we usually talk about that problem every day even if nothing new has
happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

12. ... we talk about all of the reasons why the problem might have happened.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

13. ... we spend a lot of time talking about what bad things are going to happen
because of the problem.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

14. ... we try to figure out everything about the problem, even if there are parts that
we may never understand.
1
Not At All True

2
A Little True

3
Somewhat True

4
Mostly True

5
Really True

15. ... we spend a long time talking about how sad or mad the person with the
problem feels.
1
Not At All True

2
A Little True

3
Somewhat True

CRQ Scoring: Mean rating of the 27 items

4
Mostly True

5
Really True

138
Appendix J

FASM
A. In the past year, have you engaged in the following behaviors to
deliberately harm yourself (check all that apply):
No

Yes

How many
times?

Have you
gotten
medical
treatment?

1. cut or carved on your skin
2. hit yourself on purpose
3. pulled your hair out
4. gave yourself a tattoo
5. picked at a wound
6. burned your skin (i.e., with a
cigarette, match or other hot
object)
7. inserted objects under your
nails or skin
8. bit yourself (e.g., your mouth or
lip)
9. picked areas of your body to
the point of drawing blood
10. scraped your skin
11. "erased" your skin
12. other: _______________

B. If not in the past year, have you EVER done any of the above acts?
_____ Yes
_____ No

If yes to any of the above behaviors in the past year, please complete the
questions (C-H) below:

139

C. While doing any of the above acts, were you trying to kill yourself?
_____ Yes
_____ No
D. How long did you think about doing the above act(s) before actually doing
it?
_____ none
_____ “a few minutes”
_____ < 60 minutes
_____ > 1 hour but < 24 hours
_____ more than 1 day but less than a week
_____ greater than a week
E. Did you perform any of the above behaviors while you were taking drugs
or alcohol?
_____ Yes
_____ No
F. Did you experience pain during this self-harm? _____ severe pain
_____ moderate pain
_____ little pain
_____ no pain
G. How old were you when you first harmed yourself in this way?
__________

140
FASM Scoring
Part A:
-Whether engaged in self-injury (1) or not (0) – if indicated “yes” for any self-injurious
behaviours A1 through A12; given a 1, if not, given a 0.
-Total Frequency: Add total # of times given for items A1 through A12.
-Whether received medical treatment (1) or not (0) – if indicated “yes” then rated (1) and if
“no” rated (0), then numbers summed for total.
Part B:
Yes = 1
No = 0
Part C:
Yes = 1
No = 0
Part D:
1 = None
2 = “A few mintues”
3 = < 60 minutes
4 = > 1 hour but < 24 hours
5 = More than one day but less than a week
6 = Greater than a week
Part E:
Yes = 1
No = 0
Part F:
4 = severe pain
3 = moderate pain
2 = little pain
1 = no pain
Part G:
Participant puts age in blank.

141
Appendix K
Peer Self-Injury
Think of your best or closest friends. Have your friends deliberately harmed
themselves in any of the ways listed below (without intending to kill
themselves)? Check Yes or No in the chart below.
If Yes, how many times (give a number) would you estimate they
have hurt themselves in the past year? (Answer in chart below)
No

1. cut or carved on their skin
2. hit themselves on purpose
3. pulled their hair out
4. gave themselves a tattoo
5. picked at a wound
6. burned their skin (i.e., with a
cigarette, match or other hot
object)
7. inserted objects under their
nails or skin
8. bit themselves (e.g., your
mouth or lip)
9. picked areas of their body to
the point of drawing blood
10. scraped their skin
11. "erased" their skin
12. other: _______________

Yes

How many
times in the
past year?

142
Peer Self-Injury Scoring
-Whether peer engaged in self-injury (1) or not (0) – if indicated “yes” for any selfinjurious behaviours A1 through A12; given a 1, if not, given a 0.
-Total Frequency: Add total # of times given for items A1 through A12.

143
Appendix L
ALEQ
INSTRUCTIONS: In this questionnaire we are interested in whether certain events have
happened to you in the past 3 months. Please answer how often the following events
have happened to you in the past 3 months using this scale:
0
1
2
3
4
Never
Rarely
Sometimes
Frequently
Always
_________________________________________________________________________
FAMILY AND PARENTS
1. Your parents divorced.
2. A close family member (parent, brother, sister) hospitalized for serious injury/illness.
3. A close family member (parent, brother, sister) died.
4. A close family member (parent, brother, sister) was arrested.
5. You and your family moved to a new town, but you didn’t want to move.
6. You had an argument with a close family member (parent, brother, sister).
7. A close family member (parent, brother, sister) lost their job.
8. A close family member (parent, brother, sister) can’t work due to injury/illness.
9. Have to do chores/ work you don’t want to do.
10. Have to take care of brothers/ sisters when you don’t want to.
11. Don’t spend as much time with close family members as you want to.
12. You can’t seem to please your parents.
13. Did something you didn’t want to do to please a close family member.
14. Parents put you down.
15. Seems like your parent are disappointed with you.
16. Close family member has significant medical or emotional problems (examples:
heart disease, cancer, depression, etc.).
17. Don’t receive the love, respect, or interest from parents that you wanted (example:
parents didn’t notice or compliment you on a good job).
18. Fight with parents over personal goals, desires, or choice of friends.
19. Your parents force you to achieve things you don’t want to do.
20. Close family members withdraws love or affection from you.
21. Parents criticized you or yelled at you for not doing well in school.
22. Your parents grounded you.
23. Your parents won’t let you go out with your friends.
24. You get in a fight with your parents over friends/ boyfriend/ girlfriend.
RELATIONSHIPS
25. A boyfriend/girlfriend breaks up with you, but you still want to go out with them.
26. Don’t have a boyfriend/ girlfriend when you want one.
27. Got in a fight/ argument with a boyfriend/ girlfriend.
28. Can’t seem to please girlfriend/ boyfriend when you want to.
29. Girlfriend/ boyfriend criticizes you.
30. Found out that boyfriend/ girlfriend has been cheating on you.
31. Did something to please you boyfriend/ girlfriend that you didn’t want to do.
SCHOOL AND CLASSES
32. Did poorly on, or failed, a test or class project.
33. Do not have time to do well in school (example, working too many hours at work).
34. Got a bad report card.
35. Didn’t get to take a class you wanted to take.

______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
_____
______
______
______
______
______
______
______
______
______
______

144
36. Didn’t make the honor roll when you wanted to.
37. Had a bad teacher.
38. Didn’t understand the material the teacher was teaching you.
39. Have to attend a class that you don’t like.
40. Didn’t complete required homework assignment for class.
41. Got in trouble with the teacher or principal.
42. Didn’t get accepted for an extracurricular activity you wanted to be a part of.
FRIENDS AND SOCIAL ACTIVITIES
43. Don’t have as many friends as you would like to.
44. Aren’t friends with the people you want to be friends with.
45. Don’t get invited to parties or dances.
46. Didn’t have anyone to go out with on the weekends when you wanted to go out.
47. You had an argument with a close friend.
48. Your friends don’t seem to understand you.
49. Don’t have time to spend with your friends when you want to be with them.
50. Don’t talk or share feelings with your friends.
51. Got in a fight/ argument with your friends.
52. Friends pressure you to do things you don’t want to do.
53. A close friend was arrested.
54. A close friend was hospitalized for a serious injury/illness.
55. A close friend died.
56. A close friend moved away.
57. Close friends withdraw their affection from you.

______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______
______

145
ALEQ SPSS Syntax for Scoring
Overall independent events, regardless of dependence
COMPUTE interp1 =
(calq01_1+calq02_1+calq03_1+calq04_1+calq06_1+calq08_1+calq10_1+calq11_1+calq
12_1
+calq13_1+calq14_1+calq16_1+calq17_1+calq18_1+calq20_1+calq22_1+calq23_1+cal
q24_1
+calq25_1+calq26_1+calq27_1+calq28_1+calq29_1+calq30_1+calq31_1+calq43_1+cal
q44_1
+calq47_1+calq48_1+calq49_1+calq50_1+calq51_1+calq52_1+calq53_1+calq54_1+cal
q55_1
+calq56_1+calq57_1).
EXECUTE.
Overall achievement events. These cannot be separated into dependence vs independence
COMPUTE achieve1 =
(calq09_1+calq15_1+calq19_1+calq21_1+calq32_1+calq33_1+calq34_1+calq35_1
+calq36_1+calq38_1+calq42_1).
EXECUTE.
Interpersonal dependent events
COMPUTE interdep1 = (calq06_1+calq10_1+calq11_1+calq12_1
+calq13_1+calq14_1+calq18_1+calq20_1+calq22_1+calq23_1+calq24_1
+calq25_1+calq26_1+calq27_1+calq28_1+calq29_1+calq31_1+calq41_1+calq43_1+cal
q44_1
+calq47_1+calq48_1+calq49_1+calq50_1+calq51_1+calq52_1).
EXECUTE.
Interpersonal independent events
COMPUTE interind1 = (calq01_1+calq02_1+calq03_1+calq04_1+calq08_1+
calq16_1+calq17_1+calq30_1+calq53_1+calq54_1+calq55_1+calq56_1+calq57_1).
EXECUTE.