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.
Keywords: normative perception; self-harm; social influence; social norms; suicide.