Peer influence and nonsuicidal self injury: longitudinal results in community and clinically-referred adolescent samples

Adolescent Suicide as a Failure of Acute Stress-Response Systems

Suicide is the second leading cause of death worldwide for adolescents. Despite decades of research on correlates and risk factors for adolescent suicide, we know little about why suicidal ideation and behavior frequently emerge in adolescence and how to predict, and ultimately prevent, suicidal behavior among youths. In this review, we first discuss knowledge regarding correlates, risk factors, and theories of suicide. We then review why adolescence is a period of unique vulnerability, given changing biology and social network reorganization. Next, we present a conceptual model through which to interpret emerging findings in adolescent suicide research. We suggest that a promising area for future research is to examine adolescent suicide as a failure of biological responses to acute stress in the proximal moments of a suicidal crisis. After reviewing initial evidence for this conceptualization, we review future directions for studies on adolescent suicide.

Non-Suicidal self-injury and suicide in depressed Adolescents: Impact of peer victimization and bullying

BACKGROUND

While prior research has demonstrated that peer victimization and bully perpetration contribute to non-suicidal self-injury (NSSI) and suicidal thoughts and behaviors (STBs), it remains unclear whether these interpersonal processes differentiate self-injuring adolescent suicide ideators and attempters.

METHODS

The study included adolescents aged 13-18 years (n = 223; M = 15.31, SD = 1.34) recruited from an acute inpatient program. Participants were divided into two groups: (1) NSSI_SI (n = 106): endorsed past year NSSI, current suicide ideation, and no lifetime suicide attempts and (2) NSSI_SI+SA (n = 117): endorsed past year NSSI, current suicide ideation, and lifetime suicide attempts. Adolescents completed clinical interviews (i.e., mental disorders, NSSI, and STBs) and self-report measures assessing peer victimization, bully perpetration, and depression severity.

RESULTS

NSSI_SI+SA youth reported higher levels of peer victimization and bully perpetration than NSSI_SI youth (ps < 0.01, ds = 0.36-0.37). Among the NSSI_SI+SA youth, bully perpetration was associated with a greater number of past month suicide attempts (p = 0.02, RR = 1.07). Only peer victimization was associated with greater NSSI behaviors in the past month (p = 0.04, RR = 1.01).

LIMITATIONS

The study is cross-sectional, and reports of peer victimization and bully perpetration rely on self-report assessment.

CONCLUSIONS

Peer victimization and bully perpetration differentiated adolescent suicide ideators and attempters, highlighting the need to address bully perpetration in addition to peer victimization in suicide interventions and research.

Understanding experiences of the self-harm of others: A qualitative exploration of the views of young people with complex mental health needs

As adolescent self-harm is a growing public health concern, more research is needed to identify potential risk factors. Studies have highlighted that exposure to the self-harm of others may be a risk factor associated with engagement in self-harm. However, research investigating young people's experiences of the self-harm of others has been limited. This qualitative study aimed to explore young people's experiences of the self-harm of others and interviewed a total of eight young people (five females and three males; aged between 13 and 18 years) resident at one of two adolescent mental health inpatient units in the North of England. The interviews were analysed using Interpretative Phenomenological Analysis and four themes were identified: 'Pre-admission exposure to self-harm', 'Exposure on the inside: An unpleasant environment', 'Helper vs helped' and 'Separation from the attention seekers: competing for authenticity'. Prevention efforts to reduce the social transmission and stigma surrounding self-harm among young people are discussed.

Using Exploratory Data Mining to Identify Important Correlates of Nonsuicidal Self-Injury Frequency

OBJECTIVE

Non-suicidal self-injury (NSSI) has been linked to many adverse outcomes, with more frequent NSSI increasing the likelihood of impairment, severity, and more serious self-harming behavior (e.g., suicidality; Andover & Gibb, 2010; Darke et al., 2010). Despite the determined importance of NSSI frequency in understanding the severity of one's behavior, there is still a need to identify which constructs may be influential in predicting frequency. The current study aimed to fill this gap by identifying which correlates are most important in relation to NSSI frequency through two exploratory data mining methods.

METHOD

Seven hundred twelve undergraduate students with a history of NSSI completed self-report measures of NSSI behavior, suicidality, cognitive-affective deficits, and psychopathology symptomology.

RESULTS

Both exploratory data mining methods, lasso regression and random forests, demonstrated number of NSSI methods to be the factor with the most importance in relation to lifetime NSSI frequency. Once this variable was removed, suicide plan and depressive symptomology were significant correlates across methods.

CONCLUSIONS

The current findings support the literature between NSSI frequency and NSSI methods, but also implicate suicide plans, an often-overlooked factor, and depression in NSSI severity.

Understanding the social context of adolescent nonsuicidal self-injury

OBJECTIVE

Research investigating the social context of adolescent nonsuicidal self-injury (NSSI) has been limited. We therefore examined social characteristics of NSSI, such as knowledge of friends' NSSI and the role friends play in continuing NSSI, and their relationships to other known NSSI correlates, such as suicidality.

METHOD

We assessed NSSI characteristics, including social features, in a community sample of 89 self-injuring adolescents. We also assessed psychosocial correlates of NSSI, including impulsivity, self-concept, and psychiatric symptoms.

RESULTS

Knowledge of friends' NSSI was relatively common among self-injurers. In addition, knowledge of friends' NSSI was associated with use of more NSSI methods, cutting behaviors, and suicidal ideation, but not with other NSSI correlates. However, teaching or encouragement of NSSI by friends was rare.

CONCLUSIONS

Knowledge of friends' NSSI may serve as marker of increased severity among adolescent self-injurers. These findings have implications for identifying and intervening with high-risk self-injuring youth.

Assessing Non-Suicidal Self-Injury in the Laboratory

The majority of non-suicidal self-injury (NSSI) research has used self- or clinician-rated measures of behavior which (a) are subject to reporting biases, or (b) have limited use in experimental designs that could illuminate causal relationships. Laboratory-based behavioral tasks have therefore been developed to assess NSSI-related behaviors more directly. We reviewed the behavioral methods that have been developed to assess NSSI tendencies or behaviors over the past 30 years. Several categories of laboratory analogues were identified: NSSI-related stimuli (e.g., NSSI pictures, implicit association tasks, guided imagery), experimenter administered pain stimuli (e.g., cold, heat, pressure, shock, and blade), and self-selected pain stimuli (e.g., cold and shock). These behavioral methods assess various aspects of NSSI and all have distinct advantages and shortcomings. Overall, these approaches have made significant contributions to the field complementing self- and clinician-ratings.

A Systematic Literature Review of Experiences of Professional Care and Support Among People Who Self-Harm

Self-harm is an increasing phenomenon among young people, with potentially fatal outcomes. Patient's perceptions of treatment and support are poorly documented. The aim was to synthesise the experiences of those who self-harm, with special reference to professional care and support by family, friends, and the school system. A systematic review of the literature was conducted. Following retrieval of 1,623 abstracts, 14 studies were included in the final analysis, 11 of which are reported here. Two quantitative studies as well as 1 mixed method study on self-care could not be reported on here due to word limitations. Adult people who self-harm described the importance of quality in the caring relationship and a tailored care designed for each individual. There is a need for more studies into adolescents who self-harm but of importance is the adolescents' need for support from the adult world. A positive relationship between patient and healthcare professional can be crucial in motivating continued treatment of people who self-harm. A major priority is radical improvement in the attitudes of healthcare personnel.

Nonsuicidal self-injury in community adolescents: A systematic review of prospective predictors, mediators and moderators

Nonsuicidal self-injury (NSSI) usually starts during adolescence and is associated with an array of psychological and psychiatric symptoms and future suicide attempts. The aim of this study is to determine prospective predictors, mediators and moderators of NSSI in adolescent community samples in order to target prevention and treatment strategies. Two team members searched online databases independently. Thirty-nine studies were included in the review. Several variables were seen to prospectively predict NSSI: female gender, family-related variables, peer victimisation, depression, previous NSSI and self-concept. Few studies analysed mediators and moderators. Low self-concept was highlighted as a relevant moderator in the relationship between intra/interpersonal variables and NSSI. Implications of these findings are discussed. The considerable heterogeneity between studies posed a limitation to determine robust predictors of NSSI. Further prospective studies using standardised measures of predictors and outcomes are needed to ascertain the most at risk individuals and develop prevention strategies.

Effect of guided, structured, writing program on self-harm ideations and emotion regulation

AIMS

This study investigated the efficacy of structured writing on reducing self-harm ideations and enhancing emotion regulation.

METHODS

Japanese university students (N=22) participated in the study. Participants were randomly assigned to the structured writing group (n=10; 70% female), or an assessment only control group (n=12; 67% female). For three consecutive days, participants in the intervention group performed structured writing that included psycho-education and self-reflection about emotions. The Self-Harm Ideation Scale, the Generalized Expectancy for Negative Mood Regulation Scale, and the Acceptance and Action Questionnaire-II were used to assess outcomes.

RESULTS

Structured writing had a short-term effect on expectancies for self-regulation of negative moods and acceptance of negative emotions, but had a limited effect on self-harm ideations.

CONCLUSION

This study presents preliminary evidence that increasing awareness, learning, and reflection about emotions resulting from using a structured writing program is particularly useful for regulating emotions. J. Med. Invest. 64: 74-78, February, 2017.

Examining the scope and patterns of deliberate self-injurious cutting content in popular social media

BACKGROUND

Social networking services (SNS) have rapidly become a central platform for adolescents' social interactions and media consumption patterns. The present study examined a representative sample of publicly accessible content related to deliberate self-injurious cutting across three SNS platforms: Twitter, Tumblr, and Instagram.

METHODS

Data collection simulated searches for publicly available deliberate self-injury content on Twitter, Tumblr, and Instagram. Over a six-month period at randomly generated time points, data were obtained by searching "#cutting" on each SNS platform and collecting the first 10 posts generated. Independent evaluators coded posts for presence of the following: (a) graphic content, (b) negative self-evaluations, (c) references to mental health terms, (d) discouragement of deliberate self-injury, and (e) recovery-oriented resources. Differences across platforms were examined.

RESULTS

Data collection yielded a sample of 1,155 public posts (770 of which were related to mental health). Roughly 60% of sampled posts depicted graphic content, almost half included negative self-evaluations, only 9.5% discouraged self-injury, and <1% included formal recovery resources. Instagram posts displayed the greatest proportion of graphic content and negative self-evaluations, whereas Twitter exhibited the smallest proportion of each.

CONCLUSIONS

Findings characterize the graphic nature of online SNS deliberate self-injury content and the relative absence of SNS-posted resources for populations seeking out deliberate self-injurious cutting content. Mental health professionals must recognize the rapidly changing landscape of adolescent media consumption, influences, and social interaction as they may pertain to self-harm patterns.

Development of self-inflicted injury: Comorbidities and continuities with borderline and antisocial personality traits

Self-inflicted injury (SII) is a continuum of intentionally self-destructive behaviors, including nonsuicidal self-injuries, suicide attempts, and death by suicide. These behaviors are among the most pressing yet perplexing clinical problems, affecting males and females of every race, ethnicity, culture, socioeconomic status, and nearly every age. The complexity of these behaviors has spurred an immense literature documenting risk and vulnerability factors ranging from individual to societal levels of analysis. However, there have been relatively few attempts to articulate a life span developmental model that integrates ontogenenic processes across these diverse systems. The objective of this review is to outline such a model with a focus on how observed patterns of comorbidity and continuity can inform developmental theories, early prevention efforts, and intervention across traditional diagnostic boundaries. Specifically, when SII is viewed through the developmental psychopathology lens, it becomes apparent that early temperamental risk factors are associated with risk for SII and a range of highly comorbid conditions, such as borderline and antisocial personality disorders. Prevention efforts focused on early-emerging biological and temperamental contributors to psychopathology have great potential to reduce risk for many presumably distinct clinical problems. Such work requires identification of early biological vulnerabilities, behaviorally conditioned social mechanisms, as well as societal inequities that contribute to self-injury and underlie intergenerational transmission of risk.

Youth self-harm in low- and middle-income countries: Systematic review of the risk and protective factors

BACKGROUND

Self-harm (defined here as an act of intentionally causing harm to own self, irrespective of the type, motive or suicidal intent) is one of the strongest antecedents of suicide in youth. While there have been a number of studies of youth self-harm in low- and middle-income countries (LMICs), there is currently no systematic review of studies of prevalence rates and risk and protective factors.

AIM

To systematically review the evidence relating to the prevalence rates and forms of self-harm in youth in LMICs and its relationship to family economic status, family functioning, relationship with the peer group, social relationships and academic performance.

METHODS

Electronic searches of three databases, MEDLINE, PsycINFO and Scopus, were performed. In total, 27 school-, community- and hospital-based studies evaluating self-harm in LMICs with youth focus (with participants between 12 and 25 years) were included.

RESULTS

The self-harm was divided into suicidal and non-suicidal depending on the nature of self-harm. The 12-month prevalence rates of non-suicidal self-harm varied from 15.5% to 31.3%, and the range of suicidal behaviour rates was from 3.2% to 4.7%. Banging and hitting were the most common in the community-based studies, followed by cutting, scratching and wound picking. Self-poisoning with pesticides was most commonly reported in hospital-based studies. Risk factors for self-harm were family conflict, peer groups with members indulging in self-harm, truancy and school absenteeism. Protective factors were having an understanding family, having friends and higher school competence. Risk factors for suicidal thoughts and attempts were lack of close friends and history of suicide by a friend.

CONCLUSION

The 12-month prevalence rates of youth self-harm in LMICs are comparable to high-income countries (HICs). The profile of risk and protective factors suggests that family-based interventions could be useful in treatment and prevention. Future studies should aim for greater consistency in assessment methods and the constructs under evaluation.

The Associations Between Children's and Adolescents' Suicidal and Self-Harming Behaviors, and Related Behaviors Within Their Social Networks: A Systematic Review

Social influences-including the suicidal and self-harming behaviors of others-have been highlighted as a risk factor for suicidal and self-harming behavior in young people, but synthesis of the evidence is lacking. A systematic review of 86 relevant papers was conducted. Considerable published evidence was obtained for positive associations between young people's suicidal and self-harming behavior and that of people they know, with those reporting knowing people who had engaged in suicidal or self-harming behaviors more likely to report engaging in similar behaviors themselves. Findings are discussed in relation to a number of methodological and measurement issues-including the role of normative perceptions-and implications for the prevention of suicidal and self-harming behavior are considered.

The Social Norms of Suicidal and Self-Harming Behaviours in Scottish Adolescents

Although the suicidal and self-harming behaviour of individuals is often associated with similar behaviours in people they know, little is known about the impact of perceived social norms on those behaviours. In a range of other behavioural domains (e.g., alcohol consumption, smoking, eating behaviours) perceived social norms have been found to strongly predict individuals' engagement in those behaviours, although discrepancies often exist between perceived and reported norms. Interventions which align perceived norms more closely with reported norms have been effective in reducing damaging behaviours. The current study aimed to explore whether the Social Norms Approach is applicable to suicidal and self-harming behaviours in adolescents. Participants were 456 pupils from five Scottish high-schools (53% female, mean age = 14.98 years), who completed anonymous, cross-sectional surveys examining reported and perceived norms around suicidal and self-harming behaviour. Friedman's ANOVA with post-hoc Wilcoxen signed-ranks tests indicated that proximal groups were perceived as less likely to engage in or be permissive of suicidal and self-harming behaviours than participants' reported themselves, whilst distal groups tended towards being perceived as more likely to do so. Binary logistic regression analyses identified a number of perceived norms associated with reported norms, with close friends' norms positively associated with all outcome variables. The Social Norms Approach may be applicable to suicidal and self-harming behaviour, but associations between perceived and reported norms and predictors of reported norms differ to those found in other behavioural domains. Theoretical and practical implications of the findings are considered.

Concurrent adversities and deliberate self-harm among indigenous Sami and majority Norwegian adolescents: the Norwegian Arctic Adolescent Health Study

Background:

Few studies have investigated proximal relationships between deliberate self-harm (DSH) and concurrent adversities.

Objective:

We aimed to investigate these relationships in a community population of 4881 indigenous Sami and majority Norwegian adolescents, 15 to 16 years old, and related to ethnicity and gender.

Methods:

Youth with and without self-reports of DSH last year were compared on 12 concurrent adversities, on scales measuring family and peer functioning, and on sociodemographic conditions.

Results:

DSH last year was reported by 22.3% of the adolescents, and by more girls (28.8%) than boys (15.9%). All 12 concurrent adversities were related strongly to DSH last year. Deliberate self-harmers reported twice as many concurrent adversities as non-DSHs, and a large effect size (Cohen’s d = 0.80) indicated a strong multiple additive relationship, but among DSHs no ethnic or gender differences were found. Multivariately, among Sami youth sexual abuse [odds ratio (OR), 8.4] was strongly related to DSH, whereas among majority Norwegians sexual abuse (OR, 3.9) and violence (OR, 4.5) were identified as the strongest predictors. Similarly, among boys violence from adults (OR, 8.8) was associated most strongly with DSH, whereas among girls sexual abuse (OR, 4.3) was the most robust predictor. DSHs reported more conflicts with parents, less family support and involvement, and more peer problems than non-DSHs, and DHS girls had more difficulties in these relationships than DHS boys. Only small ethnic differences were found.

Conclusion:

Adolescent DSHs reported twice as many concurrent adversities as non-DSHs, sexual abuse and violence were strongly related to DSH. Ethnic and gender differences in risk factors were found. Clinicians should inquire about traumatic experiences such as sexual and physical abuses, and should have a family, peer, and gender perspective in their work.

Response Inhibition, Peer Preference and Victimization, and Self-Harm: Longitudinal Associations in Young Adult Women with and without ADHD

Self-harm (suicidal ideation and attempts; non-suicidal self-injuries behavior) peaks in adolescence and early-adulthood, with rates higher for women than men. Young women with childhood psychiatric diagnoses appear to be at particular risk, yet more remains to be learned about the key predictors or mediators of self-harm outcomes. Our aims were to examine, with respect to self-harm-related outcomes in early adulthood, the predictive validity of childhood response inhibition, a cardinal trait of attention-deficit hyperactivity disorder (ADHD), as well as the potential mediating effects of social preference and peer victimization, ascertained in early adolescence. Participants were an ethnically and socioeconomically diverse sample of 228 girls with and without ADHD, an enriched sample for deficits in response inhibition. Childhood response inhibition (RI) predicted young-adult suicide ideation (SI), suicide attempts (SA), and non-suicidal self-injury (NSSI), over and above full-scale IQ, mother's education, household income, and age. Importantly, teacher-rated social preference in adolescence was a partial mediator of the RI-SI/SA linkages; self-reported peer victimization in adolescence emerged as a significant partial mediator of the RI-NSSI linkage. We discuss implications for conceptual models of self-harm and for needed clinical services designed to detect and reduce self-harm.

Position paper for guiding response to non-suicidal self-injury in schools

Around the world, school staff are increasingly expressing concern about nonsuicidal self-injury (NSSI) and how best to address this behavior in the school setting. However, there is a notable lack of informed guidance for schools, and clear inconsistencies in the practices school staff adopt. In this position paper we draw on our collective research and clinical expertise to provide best-practice guidelines for addressing NSSI in school settings. We outline the importance of a school protocol, and the key features all school protocols should contain. We also focus on how schools can minimize contagion of NSSI within their school environment. We believe these guidelines will be an important starting point for schools interested in developing an evidence-based approach to addressing NSSI.

The Association of Genetic Predisposition to Depressive Symptoms with Non-suicidal and Suicidal Self-Injuries

Non-suicidal and suicidal self-injury are very destructive, yet surprisingly common behaviours. Depressed mood is a major risk factor for non-suicidal self-injury (NSSI), suicidal ideation and suicide attempts. We conducted a genetic risk prediction study to examine the polygenic overlap of depressive symptoms with lifetime NSSI, suicidal ideation, and suicide attempts in a sample of 6237 Australian adult twins and their family members (3740 females, mean age = 42.4 years). Polygenic risk scores for depressive symptoms significantly predicted suicidal ideation, and some predictive ability was found for suicide attempts; the polygenic risk scores explained a significant amount of variance in suicidal ideation (lowest p = 0.008, explained variance ranging from 0.10 to 0.16 %) and, less consistently, in suicide attempts (lowest p = 0.04, explained variance ranging from 0.12 to 0.23 %). Polygenic risk scores did not significantly predict NSSI. Results highlight that individuals genetically predisposed to depression are also more likely to experience suicidal ideation/behaviour, whereas we found no evidence that this is also the case for NSSI.

The neurobiology of self-knowledge in depressed and self-injurious youth

There is limited information regarding the neurobiology underlying non-suicidal self-injury (NSSI) in clinically-referred youth. However, the salience of disturbed interpersonal relationships and disrupted self-processing associated with NSSI suggests the neural basis of social processes as a key area for additional study. Adolescent participants (N=123; M=14.75 years, SD=1.64) were divided into three groups: NSSI plus depression diagnosis (NSSI), depression only (DEP), healthy controls (HC). In the scanner, participants completed an Interpersonal Self-Processing task by taking direct (own) and indirect (mothers', best friends', or classmates') perspectives regarding self-characteristics. Across all perspectives, NSSI showed higher BOLD activation in limbic areas, and anterior and posterior cortical midline structures versus DEP and HC, while HC showed greater activity in rostrolateral, frontal pole and occipital cortex than NSSI and DEP youth. Moreover, NSSI youth showed heightened responses in amygdala, hippocampus, parahippocampus, and fusiform when taking their mothers' perspective, which were negatively correlated with self-reports of the mother's support of adolescents' emotional distress in the NSSI group. NSSI youth also yielded greater precuneus and posterior cingulate cortex activity during indirect self-processing from their classmates' perspective. Findings suggest a role for disruptions in self- and emotion-processing, and conflicted social relationships in the neurobiology of NSSI among depressed adolescents.

The Interactive Effects of Impulsivity and Negative Emotions on Adolescent Nonsuicidal Self-injury: A Latent Growth Curve Analysis

This study employed latent growth curve analysis to evaluate the interactive effects of two specific facets of impulsivity (i.e., negative urgency [NU] and premeditation [PRE]) and negative emotions (NE) on the developmental trajectory of nonsuicidal self-injury (NSSI) among 3,453 (57% females) Chinese community adolescents. Participants completed questionnaires assessing NSSI, NU, PRE, and NE (i.e., depression, anxiety, and stress) at three waves of time. The initial levels of NE and NU significantly predicted the initial level of NSSI. Changes in NE and NU significantly predicted change in NSSI. Moreover, the initial levels of NU and PRE significantly moderated the relationship between the initial levels of NE and NSSI, such that among individuals with higher NU or less PRE, the three NE were associated with a higher level of NSSI. Additionally, among individuals with a faster increase in NU, depression and anxiety were associated with a faster increase in NSSI. These findings suggest that adolescents with trait impulsivity, especially in the form of NU, are more vulnerable to the engagement in NSSI.

Peer group impulsivity moderated the individual-level relationship between depressive symptoms and adolescent nonsuicidal self-injury

This study examined the influence of impulsive friendship group contexts on nonsuicidal self-injury (NSSI) and how peer group impulsivity (i.e. negative urgency and premeditation) moderated the individual level relationship between depression and NSSI among 1701 Chinese secondary school students (1147 females). Participants were assessed twice over a 6-month interval. After controlling for direct socialization effects for NSSI, multilevel analysis indicated that friendship group negative urgency exerted a significant influence on NSSI. Additionally, friendship group premeditation weakened the relation between individual depression and NSSI, while friendship group negative urgency strengthened the relation between depression and NSSI. The results suggest the contribution of indirect peer influence effects to NSSI.

Using Implicit and Explicit Measures to Predict Nonsuicidal Self-Injury Among Adolescent Inpatients

OBJECTIVE

To examine the use of implicit and explicit measures to predict adolescent nonsuicidal self-injury (NSSI) before, during, and after inpatient hospitalization.

METHOD

Participants were 123 adolescent psychiatric inpatients who completed measures at hospital admission and discharge. The implicit measure (Self-Injury Implicit Association Test [SI-IAT]) and one of the explicit measures pertained to the NSSI method of cutting. Patients were interviewed at multiple time points at which they reported whether they had engaged in NSSI before their hospital stay, during their hospital stay, and within 3 months after discharge.

RESULTS

At baseline, SI-IAT scores differentiated past-year self-injurers and noninjurers (t121 = 4.02, p < .001, d = 0.73). These SI-IAT effects were stronger among patients who engaged in cutting (versus noncutting NSSI methods). Controlling for NSSI history and prospective risk factors, SI-IAT scores predicted patients' subsequent cutting behavior during their hospital stay (odds ratio (OR) = 8.19, CI = 1.56-42.98, p < .05). Patients' explicit self-report uniquely predicted hospital-based and postdischarge cutting, even after controlling for SI-IAT scores (ORs = 1.82-2.34, CIs = 1.25-3.87, p values <.01). Exploratory analyses revealed that in specific cases in which patients explicitly reported low likelihood of NSSI, SI-IAT scores still predicted hospital-based cutting.

CONCLUSION

The SI-IAT is an implicit measure that is outcome-specific, a short-term predictor above and beyond NSSI history, and potentially helpful in cases in which patients at risk for NSSI explicitly report that they would not do so in the future. Ultimately, both implicit and explicit measures can help to predict future incidents of cutting among adolescent inpatients.

Meta-analysis of risk factors for nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) is a prevalent and dangerous phenomenon associated with many negative outcomes, including future suicidal behaviors. Research on these behaviors has primarily focused on correlates; however, an emerging body of research has focused on NSSI risk factors. To provide a summary of current knowledge about NSSI risk factors, we conducted a meta-analysis of published, prospective studies longitudinally predicting NSSI. This included 20 published reports across 5078 unique participants. Results from a random-effects model demonstrated significant, albeit weak, overall prediction of NSSI (OR=1.59; 95% CI: 1.50 to 1.69). Among specific NSSI risk factors, prior history of NSSI, cluster b, and hopelessness yielded the strongest effects (ORs>3.0); all remaining risk factor categories produced ORs near or below 2.0. NSSI measurement, sample type, sample age, and prediction case measurement type (i.e., binary versus continuous) moderated these effects. Additionally, results highlighted several limitations of the existing literature, including idiosyncratic NSSI measurement and few studies among samples with NSSI histories. These findings indicate that few strong NSSI risk factors have been identified, and suggest a need for examination of novel risk factors, standardized NSSI measurement, and study samples with a history of NSSI.

Self-harm in young people: Prevalence, associated factors, and help-seeking in school-going adolescents

Adolescent self-harm is recognized as a serious public health problem; however, there is little reliable comparative data on its prevalence or characteristics, or on the extent of help-seeking for self-harm. The aims of the present study were to determine the prevalence and associated factors of adolescent self-harm in an urban region in Ireland, and to investigate help-seeking behaviours for self-harm. This was a cross-sectional study of 856 school-going adolescents, employing an anonymous self-report questionnaire. A lifetime history of self-harm was reported by 12.1% of adolescents. Factors independently associated with self-harm included exposure to self-harm of a friend/family member. Professional help-seeking was uncommon prior to (9%) and after (12%) self-harm. Furthermore, only 6.9% of adolescents presented to hospital as a result of their last self-harm act. These findings indicate that self-harm is common in adolescents; however, seeking professional help is not a common phenomenon, and those who present to hospital represent the 'tip of the iceberg' of adolescent self-harm. Identifying the prevalence of self-harm and associated factors, in addition to help-seeking behaviours, in young people is important to determine the preventative programmes to target 'at-risk' groups. Mental health nurses have an important and increasing role to play in such school-based initiatives.

Risk of depression and self-harm in teenagers identifying with goth subculture: a longitudinal cohort study

BACKGROUND

Previous research has suggested that deliberate self-harm is associated with contemporary goth subculture in young people; however, whether this association is confounded by characteristics of young people, their families, and their circumstances is unclear. We aimed to test whether self-identification as a goth is prospectively associated with emergence of clinical depression and self-harm in early adulthood.

METHODS

We used data from the Avon Longitudinal Study of Parents and Children, a UK community-based birth cohort of 14 541 pregnant women with expected delivery between April 1, 1991, and Dec 31, 1992. All children in the study were invited to attend yearly follow-up visits at the research clinic from age 7 years. At 15 years of age, participants reported the extent to which they self-identified as a goth. We assessed depressive mood and self-harm at 15 years with the Development and Wellbeing Assessment (DAWBA) questionnaire, and depression and self-harm at 18 years using the Clinical Interview Schedule-Revised. We calculated the prospective association between goth identification at 15 years and depression and self-harm at 18 years using logistic regression analyses.

FINDINGS

Of 5357 participants who had data available for goth self-identification, 3694 individuals also had data for depression and self-harm outcomes at 18 years. 105 (6%) of 1841 adolescents who did not self-identify as goths met criteria for depression compared with 28 (18%) of 154 who identified as goths very much; for self-harm, the figures were 189 (10%) of 1841 versus 57 (37%) of 154. We noted a dose-response association with goth self-identification both for depression and for self-harm. Compared with young people who did not identify as a goth, those who somewhat identified as being a goth were 1·6 times more likely (unadjusted odds ratio [OR] 1·63, 95% CI 1·14-2·34, p<0·001), and those who very much identified as being a goth were more than three times more likely (unadjusted OR 3·67, 2·33-4·79, p<0·001) to have scores in the clinical range for depression at 18 years; findings were similar for self-harm. Associations were not attenuated after adjustment for a range of individual, family, and social confounders.

INTERPRETATION

Our findings suggest that young people identifying with goth subculture might be at an increased risk for depression and self-harm. Although our results suggest that some peer contagion operates within the goth community, our observational findings cannot be used to claim that becoming a goth increases risk of self-harm or depression. Working with young people in the goth community to identify those at increased risk of depression and self-harm and provide support might be effective.

FUNDING

Wellcome Trust, Medical Research Council Programme.

Nonsuicidal Self-Injury in Adolescents

Abstract. Nonsuicidal self-injury (NSSI) is a prevalent, pervasive, clinically significant behavior in adolescents, frequently associated with serious social, physical, and psychological consequences. It is characterized by high comorbidity with various disorders. Therefore, NSSI has been included as a research diagnosis in the Diagnostic and statistical manual of mental disorders (5th ed., American Psychiatric Association (APA; 2013) ; DSM-5; Section 3), as a condition requiring further study for possible future official adoption. This is a positive step toward providing researchers with a uniform definition and criteria. This state-of-the-art article gives an overview of prevalence rates, comorbidity, clinical correlates, functions, and risk factors as well as treatment and dealing with adolescents with NSSI and their Internet activities. Furthermore, the association and differences between NSSI and suicidality as well as borderline personality disorder are reviewed. The article concludes with future directions for research, for example, the dimensional approach to classification of the Research Domain Criteria project.

Testing an equifinality model of nonsuicidal self-injury among early adolescent girls

Nonsuicidal self-injury (NSSI) is a common behavior among females that has been shown to confer risk for continued self-injury and suicidal attempts. NSSI can be viewed conceptually as behavior that is pathognomonic with aggression and/or depression. Empirical research on concurrent correlates supports this concept: numerous and diverse factors are shown to be significantly associated with self-harm, including depression, emotion dysregulation, impulsivity, and aggression and other conduct problems, as well as environmental stressors such as bullying, harsh parenting, and negative life events. In the present study, we test hypotheses regarding developmental precursors (measured from ages 8 to 12 years) to NSSI in young adolescent girls (ages 13-14 years), specifically whether aggression, depression, and environmental stressors distinguish girls with and without self-harm, and whether there is evidence for multiple developmental pathways to NSSI. Data were derived from the longitudinal Pittsburgh Girls Study. In this community sample of girls, the prevalence of NSSI at ages 13 or 14 years of age was 6.0%. Initial levels in dimensions measured within the depression, aggression, and environmental stressor domains accounted for variance in NSSI in early adolescence. Changes over time in relational aggression and assertiveness were also significantly associated with risk for NSSI. To a large extent, adolescent NSSI was predicted by psychological deficits and stress exposure that began early in childhood. Risk indices were calculated using the 85th or 15th percentile. Close to 80% of girls who engaged in NSSI during adolescence were identified by at least one risk domain in childhood. A sizable proportion of adolescent girls who later engaged in NSSI had childhood risk scores in all three domains; the remaining girls with adolescent NSSI were relatively evenly distributed across the other risk domain profiles. The observation that multiple pathways to NSSI exist suggests that deficits underlying the behavior may vary and require different modes of prevention.

An evidence synthesis of risk identification, assessment and management for young people using tier 4 inpatient child and adolescent mental health services

Background

Inpatient child and adolescent mental health services are one part of a complex system, and exist to meet the needs of young people with the greatest mental health difficulties.

Objectives

The research question was ‘What is known about the identification, assessment and management of risk (where “risk” is broadly conceived) in young people (aged 11–18 years) with complex mental health needs entering, using and exiting inpatient child and adolescent mental health services in the UK?’

Data sources

The two-phase Evidence for Policy and Practice Information and Co-ordinating Centre approach was used. In phase 1, scoping searches were made using two databases with an end date of March 2013. Phase 2 centred on the search for citations relating to the risks to young people of ‘dislocation’ and ‘contagion’. Searches were made using 17 databases, with time limits from 1995 to September 2013. Websites were searched, a call for evidence circulated and references of included citations reviewed.

Review methods

Priority risk areas for phase 2 were decided in collaboration with stakeholders including through consultations with young people and the mother of a child who had been in hospital. All types of evidence relating to outcomes, views and experiences, costs and cost-effectiveness, policies, and service and practice responses in the areas of ‘dislocation’ and ‘contagion’ for young people (11–18 years) using inpatient mental health services were considered. A staged approach to screening was used. Data were extracted into tables following guidance from the Centre for Reviews and Dissemination or tables developed for the review. Quality was assessed using appraisal checklists from the Effective Public Health Practice Project or the Critical Skills Appraisal Programme or devised by previous reviewers. No papers were excluded on the grounds of quality, and all materials identified were narratively synthesised.

Results

In phase 1, 4539 citations were found and 124 included. Most were concerned with clinical risks. In phase 2, 15,662 citations were found and 40 addressing the less obvious risks of ‘dislocation’ and ‘contagion’ were included, supplemented by 20 policy and guidance documents. These were synthesised using these categories: Dislocation: Normal Life; Dislocation: Identity; Dislocation: Friends; Dislocation: Stigma; Dislocation: Education; Dislocation: Families; and Contagion. No studies included an economic analysis or economic evaluation. The importance to stakeholders of these less obvious risks contrasted with the limited quantity and quality of research capable of informing policy, services and practice in these areas.

Limitations

Included studies were of variable quality. Data derived could not be used to inform an economic modelling of NHS costs or to analyse cost-effectiveness. Other limitations were the search for only English-language materials and the use of umbrella concepts (‘dislocation’ and ‘contagion’).

Conclusions

The less obvious risks are important, but little evidence exists to support their identification, assessment and management. This has implications for services, and a programme of research is recommended to generate new knowledge.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Internet use and web communication networks, sources of social support, and forms of suicidal and nonsuicidal self-injury among adolescents: different patterns between genders

The relationships of Internet use, web communication, and sources of social support with adolescent self-injurious thoughts and behaviors (SITBs) in Taiwan were investigated. The study sample of 391 12 to 18-year-olds was selected from nine public high schools. Findings show that girls are more likely to have SITBs, except for suicide gestures. Web communication is a risk factor for SITBs in boys but not in girls. Family support is protective in both genders. Support from friends is protective and support from significant others was a risk factor for suicide plans in girls. Support from virtual social communities can have both positive and negative effects on adolescent SITBs, with different effects by gender.

Subtypes of non-suicidal self-injury based on childhood adversity

The aim of this study was to examine the latent clusters in non-suicidal self-injury (NSSI) based on childhood adversity. Data were derived from Waves I (2001-2002) and II (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample of U.S. adults. Individuals engaging in NSSI (N = 672) comprised the analytic sample. Latent class statistical analysis was undertaken to elucidate the latent structure of NSSI based on child experiences of physical and sexual abuse, neglect, and family violence. Four-classes of respondents were identified vis-à-vis childhood adversities. A low abuse/neglect class (35.7% of respondents, 91.1% male) demonstrated less mental health and substance use comorbidity and antisocial behavior. A sexual abuse class (43.1% of respondents, 98.6% female) evinced somewhat lower levels of antisocial behavior than the other classes but similarly high levels of mental health disorder and a non-sexual abuse/neglect class (8.3% of respondents, 91.5% male) characterized by varied and intensive forms of antisocial and externalizing behaviors. Finally, a severe high abuse/neglect/family violence class (12.95% of respondents, 100% female) demonstrated high levels of clinical psychiatric and personality disorders. The current project is a nationally representative study of NSSI latent clusters and extends and validates the existence of NSSI subtypes revealed by prior research.

Longitudinal analysis of adolescent NSSI: the role of intrapersonal and interpersonal factors

Non-suicidal self-injury (NSSI) occurs in approximately 10 % of adolescents. To establish effective prevention and intervention initiatives, it is important to understand onset, maintenance and cessation of NSSI. We explored whether the relationships between interpersonal factors (i.e. attachment, social support) and NSSI were mediated by intrapersonal factors (i.e. emotion regulation, self-esteem, self-efficacy). Participants were 1973 students (1414 female and 559 male) aged between 12 and 18 years (M = 13.89, SD = 0.97) recruited from 40 Australian high schools. Participants completed a questionnaire at two time-points with a 12-month interval. At baseline, 8.3 % of adolescents engaged in NSSI, increasing to 11.9 % at follow-up. Family support was most salient in onset, maintenance and cessation of NSSI. Attachment anxiety was related to NSSI onset. Of the intrapersonal variables, self-esteem and self-efficacy were significant in predicting onset of NSSI. Self-esteem, self-efficacy and cognitive reappraisal mediated the relationship between attachment anxiety and NSSI onset. A combination of interpersonal and intrapersonal variables contributes to the onset, maintenance and cessation of NSSI in adolescence. Perceived family support appears to be an important safeguard against NSSI. Strategies targeting family functioning and teaching cognitive reappraisal techniques to adolescents may reduce the number engaging in NSSI.

Longitudinal effects of psychological symptoms on non-suicidal self-injury: a difference between adolescents and young adults in China

PURPOSE

Few longitudinal studies have examined the psychological symptoms that may lead to non-suicidal self-injury (NSSI) among Chinese adolescents and young adults. This study determined the predictive effects of psychological symptoms for NSSI during a 9-month follow-up period.

METHODS

Data from 17,622 students, 12-24 years of age, were analyzed in a cross-sectional fashion with respect to associations between psychological symptoms and NSSI. Follow-up surveys were performed 3, 6, and 9 months later. Incident cases of NSSI during follow-up were correlated with the psychological symptoms at baseline.

RESULTS

A total of 3,001 (17.0%) students reported that they had NSSI in the 12 months before the initial assessment. The total rate of NSSI revealed no statistically significant differences by gender, but marked differences between grades. The response rate 3, 6, and 9 months later was 91.8, 81.8, and 79.1%, respectively. Our cross-sectional study demonstrated statistically significant associations between emotional problems, conduct problems, social adaptation problems, psychological problems, and NSSI (P < 0.01). In the longitudinal study, emotional problems, conduct problems, social adaptation problems, and psychological problems at baseline had statistically significant associations with incident NSSI in follow-up involving the adolescents, while the association in young adults was attenuated after adjustment for confounding variables. Moreover, psychological symptoms at baseline showed a monotonic dose-response relationship with NSSI in follow-up involving adolescents.

CONCLUSIONS

The findings suggest that adolescents with psychological symptoms are a group with elevated risks for later NSSI. The prevention programs of NSSI should target attenuating the severity of psychological symptoms.

The longitudinal course of non-suicidal self-injury and deliberate self-harm: a systematic review of the literature

Non-suicidal self-injury (NSSI) has been proposed as diagnostic entity and was added to the section 3 of the DSM 5. Nevertheless, little is known about the long-term course of this disorder and many studies have pointed to the fact that NSSI seems to be volatile over time. We aimed to assemble studies providing longitudinal data about NSSI and furthermore included studies using the definition of deliberate self-harm (DSH) to broaden the epidemiological picture. Using a systematic search strategy, we were able to retrieve 32 studies reporting longitudinal data about NSSI and DSH. We furthermore aimed to describe predictors for the occurrence of NSSI and DSH that were identified in these longitudinal studies. Taken together, there is evidence for an increase in rates of NSSI and DSH in adolescence with a decline in young adulthood. With regards to predictors, rates of depressive symptoms and female gender were often reported as predictor for both NSSI and DSH.

Advancing a biopsychosocial and contextual model of sleep in adolescence: a review and introduction to the special issue

Sleep problems in adolescence have been identified as an international public health issue. Over the past few decades, notable advances have been made in our understanding of the patterns and consequences of sleep in adolescence. Despite these important gains, there is much about the role of sleep in adolescence that remains to be understood. This Special Issue brings together studies that examine sleep as it specifically pertains to adolescent development and adjustment. In this introductory article, we argue for the importance of grounding the study of sleep and adolescence in developmental science and a developmental psychopathology framework. First, a review of the literature is used to outline a biopsychosocial and contextual model of sleep in adolescence. Second, attention-deficit/hyperactivity disorder (ADHD) is used as an exemplar of the proposed model given the pervasiveness of sleep problems among youth with ADHD and the likelihood that sleep problems and ADHD symptoms are interconnected in complex ways. Finally, a brief introduction to the empirical articles included in the Special Issue is provided, with particular attention given to how these articles fit within the proposed biopsychosocial and contextual model. Along with the framework proposed in this article, the studies included in this Special Issue advance the current literature and point to critical directions for future research.

Suicide contagion: a systematic review of definitions and research utility

Objectives

Despite the common use of contagion to analogize the spread of suicide, there is a lack of rigorous assessment of the underlying concept or theory supporting the use of this term. The present study aims to examine the varied definitions and potential utility of the term contagion in suicide-related research.

Methods

100 initial records and 240 reference records in English were identified as relevant with our research objectives, through systematic literature screening. We then conducted narrative syntheses of various definitions and assessed their potential value for generating new research.

Results

20.3% of the 340 records used contagion as equivalent to clustering (contagion-as-cluster); 68.5% used it to refer to various, often related mechanisms underlying the clustering phenomenon (contagion-as-mechanism); and 11.2% without clear definition. Under the category of contagion-as-mechanism, four mechanisms have been proposed to explain how suicide clusters occurred: transmission (contagion-as-transmission), imitation (contagion-as-imitation), contextual influence (contagion-as-context), and affiliation (contagion-as-affiliation). Contagion-as-cluster both confounds and constrains inquiry into suicide clustering by blending proposed mechanism with the phenomenon to be studied. Contagion-as-transmission is, in essence, a double or internally redundant metaphor. Contagion-as-affiliation and contagion-as-context involve mechanisms that are common mechanisms that often occur independently of apparent contagion, or may serve as a facilitating background. When used indiscriminately, these terms may create research blind spots. Contagion-as-imitation combines perspectives from psychology, sociology, and public health research and provides the greatest heuristic utility for examining whether and how suicide and suicidal behaviors may spread among persons at both individual and population levels.

Conclusion

Clarifying the concept of “suicide contagion” is an essential step for more thoroughly investigating its mechanisms. Developing a clearer understanding of the apparent spread of suicide-promoting influences can, in turn, offer insights necessary to build the scientific foundation for prevention and intervention strategies that can be applied at both individual and community levels.

Evidence-based psychosocial treatments for self-injurious thoughts and behaviors in youth

The purpose of this study was to review the current evidence base of psychosocial treatments for suicidal and nonsuicidal self-injurious thoughts and behaviors (SITBs) in youth. We reviewed major scientific databases (HealthSTAR, MEDLine, PsycINFO, PubMed) for relevant studies published prior to June 2013. The search identified 29 studies examining interventions for suicidal or nonsuicidal SITBs in children or adolescents. No interventions currently meet the Journal of Clinical Child and Adolescent Psychology standards for Level 1: well-established treatments. Six treatment categories were classified as Level 2: probably efficacious or Level 3: possibly efficacious for reducing SITBs in youth. These treatments came from a variety of theoretical orientations, including cognitive-behavioral, family, interpersonal, and psychodynamic theories. Common elements across efficacious treatments included family skills training (e.g., family communication and problem solving), parent education and training (e.g., monitoring and contingency management), and individual skills training (e.g., emotion regulation and problem solving). Several treatments have shown potential promise for reducing SITBs in children and adolescents. However, the probably/possibly efficacious treatments identified each have evidence from only a single randomized controlled trial. Future research should focus on replicating studies of promising treatments, identifying active treatment ingredients, examining mediators and moderators of treatment effects, and developing brief interventions for high-risk periods (e.g., following hospital discharge).

Prevalence of nonsuicidal self-injury in nonclinical samples: systematic review, meta-analysis and meta-regression

Published prevalence estimates of nonsuicidal self-injury (NSSI) among nonclinical samples are highly heterogeneous, raising concerns about their reliability and hindering attempts to explore the alleged increase in NSSI over time. Accordingly, the objectives of this study were to investigate the influence of methodological factors on heterogeneity in NSSI prevalence estimates, explore changes over time, and estimate overall international NSSI prevalence. Results showed that methodological factors contributed over half (51.6%) of the heterogeneity in prevalence estimates, and, after adjusting for these factors, NSSI prevalence did not increase over time. Overall, pooled NSSI prevalence was 17.2% among adolescents, 13.4% among young adults, and 5.5% among adults. Clearly, development of standardized methodology in NSSI research is crucial if accurate estimates are desired.

Mental health and social networks in early adolescence: a dynamic study of objectively-measured social interaction behaviors

How are social interaction dynamics associated with mental health during early stages of adolescence? The goal of this study is to objectively measure social interactions and evaluate the roles that multiple aspects of the social environment--such as physical activity and food choice--may jointly play in shaping the structure of children's relationships and their mental health. The data in this study are drawn from a longitudinal network-behavior study conducted in 2012 at a private K-8 school in an urban setting in California. We recruited a highly complete network sample of sixth-graders (n = 40, 91% of grade, mean age = 12.3), and examined how two measures of distressed mental health (self-esteem and depressive symptoms) are positionally distributed in an early adolescent interaction network. We ascertained how distressed mental health shapes the structure of relationships over a three-month period, adjusting for relevant dimensions of the social environment. Cross-sectional analyses of interaction networks revealed that self-esteem and depressive symptoms are differentially stratified by gender. Specifically, girls with more depressive symptoms have interactions consistent with social inhibition, while boys' interactions suggest robustness to depressive symptoms. Girls higher in self-esteem tended towards greater sociability. Longitudinal network behavior models indicate that gender similarity and perceived popularity are influential in the formation of social ties. Greater school connectedness predicts the development of self-esteem, though social ties contribute to more self-esteem improvement among students who identify as European-American. Cross-sectional evidence shows associations between distressed mental health and students' network peers. However, there is no evidence that connected students' mental health status becomes more similar in their over time because of their network interactions. These findings suggest that mental health during early adolescence may be less subject to mechanisms of social influence than network research in even slightly older adolescents currently indicates.

Social networks, substance use, and mental health in college students

OBJECTIVES

The relationship between social network risk (alcohol-using close friends), perceived peer closeness, substance use, and psychiatric symptoms was examined to identify risk and protective features of college students' social context.

PARTICIPANTS

Six hundred and seventy undergraduate students enrolled in a large southeastern university.

METHODS

An online survey was administered to consenting students.

RESULTS

Students with risky networks were at a 10-fold increase of hazardous drinking, 6-fold increase for weekly marijuana use, and 3-fold increase for weekly tobacco use. College students' who feel very close to their peers were protected against psychiatric symptoms yet were at increased risk for marijuana use. Perceived closeness of peers was highly protective against psychiatric symptoms, adding a natural preventive effect for a population at great risk for mental illness.

CONCLUSIONS

RESULTS support targeting college students through network-oriented preventive interventions to address substance use as well as mental health.

Negative life events and non-suicidal self-injury in an adolescent inpatient sample

Although life stressors have been implicated in the aetiology of various forms of psychopathology related to non-suicidal self-injury (NSSI), particularly depression and suicidal behavior, they have rarely been examined in relation with NSSI. The objective of the current study was to assess the association between life stressors and NSSI in adolescent inpatients. Adolescent inpatients (n = 110) completed measures of life events, NSSI, and depressive symptoms at 3 time-points over a 9-month period. Higher rates of life stressors were significantly associated with greater NSSI. This finding held even after covarying concurrent depressive symptoms and gender. Life stressors may have a unique role in the pathogenesis of NSSI. Directions for future research and clinical implications are discussed.

The role of trauma symptoms in nonsuicidal self-injury

Reports of traumatic events by individuals who engage in nonsuicidal self-injury (NSSI) are common; yet, evidence for the relation between traumatic events and NSSI is inconclusive. This review explores the thesis that trauma symptoms, rather than the experience of a traumatic event per se, underlie this relation, specifically suggesting that trauma symptoms might serve as a mediator. The literature indicates that self-injury plays an important functional role in coping with trauma symptoms such that self-injury can provide an escape from intrusive thoughts and aversive emotional states, as well as end dissociation and periods of numbness through the generation of feelings. Additionally, trauma symptoms have been shown to mediate the relation between the occurrence of traumatic events and NSSI. Taken together, trauma symptoms may play an important role in the development and maintenance of NSSI. The review concludes with treatment implications and future directions for research.

Peer effects on risky behaviors: new evidence from college roommate assignments

Social scientists continue to devote considerable attention to spillover effects for risky behaviors because of the important policy implications and the persistent challenges in identifying unbiased causal effects. We use the natural experiment of assigned college roommates to estimate peer effects for several measures of health risks: binge drinking, smoking, illicit drug use, gambling, having multiple sex partners, suicidal ideation, and non-suicidal self-injury. We find significant peer effects for binge drinking but little evidence of effects for other outcomes, although there is tentative evidence that peer effects for smoking may be positive among men and negative among women. In contrast to prior research, the peer effects for binge drinking are significant for all subgroups defined by sex and prior drinking status. We also find that pre-existing risky behaviors predict the closeness of friendships, which underscores the significance of addressing selection biases in studies of peer effects.

The best friend and friendship group influence on adolescent nonsuicidal self-injury

This study examined associations of peer socialization and selection, over time, with nonsuicidal self-injury (NSSI) among 5,787 (54.2 % females) Chinese community adolescents. Both effects were tested using two aspects of adolescents' friendship networks: the best friend and the friendship group. Participants completed questionnaires assessing NSSI, depressive symptoms and maladaptive impulsive behaviors at two waves of time over a 6-month period. Results showed that even after controlling for the effects of depressive symptoms and maladaptive impulsive behaviors, the best friends' engagement in NSSI still significantly predicted adolescents' own engagement in NSSI. Adolescents' friendship groups' NSSI status also significantly predicted their own NSSI status and frequency. Additionally, adolescents with NSSI tended to join peer groups with other members also engaging in NSSI.