Moderators and mediators of the association between bullying victimisation and self-harm and suicide in adolescents: A systematic review

Introduction: There is long-standing evidence that bullying victimisation is associated with higher rates of self-harm and suicide. However, there is little evidence clarifying why some adolescents engage in these harmful behaviours and others do not. A systematic review of the moderators and mediators of these associations was conducted to understand the factors it may be useful to focus on in interventions with victimised adolescents. Methods: A search was performed on PsycINFO, MEDLINE, Embase, CINAHL and ERIC. Two independent researchers assessed fulfilment of eligibility criteria and methodological quality. Thirty-one studies were identified which studied 27 moderators and 13 mediators. Results: Only two studies had high methodological quality and, except for depression and social support, no variables were moderators or mediators in more than one study. Limitations: The fact that this study used a quality assessment tool to assess the methodological quality of studies is a major limitation. This meant that a study could have been assessed as being medium- or high-quality overall despite scoring low on a number of factors. Conclusions: It is concluded that the evidence is not robust enough to draw conclusions about these variables as mechanisms, although depression and social support deserve further study. This is an emerging field of research and further work is recommended before any definite conclusions can be drawn.