A systematic review and narrative synthesis exploring the relationship between friendships and peer relationships, and self-harm ideation and behaviour among young people

Abstract

Friendships and peer relationships have an important role in the experience of self-harm ideation and behaviour in young people, yet they typically remain overlooked. The present systematic review and narrative synthesis explore the extant literature on this topic to identify important relationships between these constructs. A keyword search of peer-reviewed empirical articles relating to friendships and peer relationships and self-harm ideation and behaviour in young people (11-25 years old) was conducted across 11 databases (MEDLINE, Embase, PsycINFO, Web of Science, SCOPUS, PubMed, Cochrane Library, CINAHL, Sociology Database, IBSS and Sociological Abstracts) from database inception to April 2024. 90 articles were identified presenting evidence primarily from high-school adolescents (11-18 years old), mixed-gender (with a slight overrepresentation of females), White samples. Findings highlight significant, substantive relationships between the key constructs: (a) Studies of young people with self-harm ideation and behaviour show evidence that 1) characteristics of friends and peers, including their self-harm ideation and behaviour, relate to and predict ego self-harm ideation and behaviour; 2) friends and peers are important sources of support; 3) evidence on causal mechanisms is limited, but highlights potential peer selection and influence processes; b) Studies of friends and peers of young people with self-harm ideation and behaviour, highlight that 1) friends’ attitudes to self-harm and suicide influence their responses to peers’ self-harm ideation and behaviour; and 2) bereaved friends and friend supporters experience negative outcomes. Despite significant heterogeneity across samples, study designs and definition/measurement of the primary constructs, the current review represents an initial step in organising a complex literature on a critically important topic. These findings have important implications for the development of future research and evidence-based interventions.