Peers are those with lived experiences of adversity and are commonly utilised in services. However, little is known about change mecha- nisms, resulting in undefined concepts and weak assertions on peer supports’ effectiveness. Further, peer interventions are becoming increasingly common in homelessness services, without the theoretical understanding to support it. This review systematically explores literature to close this gap. Iterative searches from PsychINFO, PsychARTICLES, PubMED, MEDLINE, CINAHL, Web of Science, and grey literature resulted in 71 included sources. Through realist synthesis, a model of client and peer pathways through peer support was developed. Through inclusion of literature from multiple health contexts (i.e. homelessness, mental health, addiction, and criminal justice), the review identified mechanisms of working alliances, role modelling, experience-based social support, and processes of becoming a peer-supporter. The model asserts that 1) the working alliance quality influences client/peer outcomes, 2) clients learn behaviours modelled by peers, 3) peer outcomes are mediated by being a role model, 4) peers provide social support, impacting client/peer outcomes, and 5) training, supervision, and support are directly linked to peer- supporters’ effectiveness.
By Stephanie L. Barker, Felicity L. Bishop, Elizabeth Bodley Scott, Lusia L. Stopa and Nick J. Maguire
School of Psychology, University of Southampton, United Kingdom.