A theory of change for one-on-one peer support for older adolescents and young adults.

Peer support has become increasingly available as a formal mental health service. However, high quality research and implementation of peer support has been hampered over the years by the lack of theory that clarifies peer support roles and explains exactly how these roles foster positive outcomes for peer support users. Observers have noted that theory is particularly sparse in regard to peer support for older adolescents and young adults, and they have called for theory that not only clarifies roles and mechanisms of impact, but also identifies how peer support for young people might differ from peer support for older adults This qualitative study brought young people with experience providing and using peer support together in small group discussions focused on understanding the activities and outcomes of peer support. This information was used to develop a theory of change that outlines key activities that constitute a one-on-one peer support role for young people, and describes how and why carrying out these activities should lead to positive outcomes. The theory highlights the characteristics of a successful "peerness-based relationship," and proposes that the development of this kind of relationship mediates other positive outcomes from peer support. The article concludes with a discussion of how this theory can usefully inform the development and specification of peer support roles, training and supervision, and other organizational supports.