A realist change model for community-based perinatal mental health peer support from peer volunteers.

Aims: To investigate what it is about community-based perinatal mental health peer support from trained volunteers that works, for whom, in what circumstances, in what respects, and why; and build a change model that includes positive and negative mechanisms and outcomes.

Methods: Realist evaluation methods based on semi-structured interviews were used to create a change model for a third sector programme in England.

Results: Mothers who received peer support (n = 20), peer support volunteers (n = 27), and programme staff (n = 9) were interviewed. Positive impact on mothers was primarily based on feeling understood and accepted, social comparison (including normalisation, hope, and gaining perspective) and sharing non-directive information from experiential knowledge. Negative impact on mothers was based on negative social comparison, or absence of key peer support mechanisms. Mothers were affected in different ways, depending on individual contexts: their backgrounds, personalities, social situations, resources, experiences, beliefs, and needs. Some different mechanisms were present in one-to-one and group situations. All participants considered the benefits of peer support to greatly outweigh the risks.

Conclusion: Individual contextual factors affect the multiple mechanisms through which mental health peer support can improve mothers' emotional wellbeing and social participation. Peer support has potential risks as well as benefits, which can be mitigated. Programmes could use this understanding of how contexts and mechanisms interact to produce peer support outcomes to improve training for peer support volunteers and to design future evaluations that take into account diversity of peer support experience.