Bullying victimization/perpetration and non-suicidal self-injury: A systematic review

The longitudinal course of childhood bullying victimization and associations with self-injurious thoughts and behaviors in children and young people: A systematic review of the literature

INTRODUCTION

Bullying victimization has consistently been highlighted as a risk factor for self-injurious thoughts and behaviors (SITBs) in young people. This systematic review of prospective, community-based studies explored associations between bullying victimization (traditional/face-to-face and cyber) across the full spectrum of self-harm and suicidality, in children and young people aged up to (and including) 25 years. Importantly, associations by sex/gender were explored.

METHODS

MEDLINE, Embase, PsycINFO, CINAHL and Scopus were searched for articles meeting the inclusion criteria. Articles were screened by title, abstract and full text. Quality appraisal was performed using the Newcastle-Ottawa Scale for cohort studies. Data were synthesized narratively. The protocol is registered on PROSPERO (CRD42021261916) and followed PRISMA 2020 guidelines.

RESULTS

A total of 35 papers were included, across 17 countries. Results were presented by bullying type: traditional/face-to-face (n = 25), cyber (n = 7) and/or an aggregate of both types (n = 7). Outcomes included suicidal ideation (n = 17), self-harm (n = 10), suicide attempt (n = 4), NSSI (n = 4), other (n = 7). Studies measured outcomes in under 18s (n = 24), 18-25-year-olds (n = 8) and both under 18s and 18-25-year-olds (n = 3). Studies exploring the role of sex/gender (20%) found some interesting nuances.

CONCLUSIONS

Some weak to strong associations between bullying and SITBs were found yet conclusions are tentative due to study heterogeneity (e.g., methods used, conceptualizations and operationalisations of exposures/outcomes). Future research should address methodological issues raised in this review, and further explore gender differences in bullying, including by bullying sub-types (e.g., overt or relational) and victim status (e.g., victim or bully-victim).

Peer victimization, depression, and non-suicidal self-injury among Chinese adolescents: the moderating role of the 5-HTR2A gene rs6313 polymorphism

BACKGROUND

Peer victimization is a crucial risk predictor for adolescent non-suicidal self-injury (NSSI). However, adolescent NSSI reactions to peer victimization exhibit large individual differences. This study explored whether depression mediated the association between peer victimization and adolescent NSSI, and whether this mediating path was moderated by the 5-HTR2A gene rs6313 polymorphism.

METHODS

A total of 667 adolescents (Mean_age = 12.81, SD = 0.48) completed questionnaires regarding peer victimization, depression, and NSSI. Genomic DNA was extracted from saliva and buccal cells from each participant.

RESULTS

The results showed that the positive relation between peer victimization and adolescent NSSI was mediated by depression. Moreover, the triple interaction between peer victimization, rs6313 polymorphism, and gender on adolescent depression was significant. And the triple interaction between depression, rs6313 polymorphism, and gender on adolescent NSSI was also significant. Specifically, the risk effect of peer victimization on adolescent NSSI through increased depression was stronger for female adolescents with CC genotype than for female adolescents with CT or TT genotype, and male adolescents with CT or TT genotype. However, the indirect effect was nonsignificant for male adolescents with CC genotype.

CONCLUSIONS

These findings promote the etiological understanding of adolescent NSSI, highlighting the mediating and moderating effect between peer victimization and NSSI, and adding evidence supporting the relationship between the 5-HTR2A gene rs6313 polymorphism, depression and adolescent NSSI.