Although peer support is increasingly used in mental health services worldwide, service users' experiences have been studied mostly in high-income countries.The current study examined service users' experiences of peer support in the UPSIDES Trial, delivered across diverse cultural and resource contexts, including high, middle and low-income countries.Semi-structured interviews were conducted with 33 service users across six study sites (Germany two sites, Uganda, Tanzania, Israel, and India) and analysed using thematic analysis to identify patterns in participants' experiences.To capture diverse perspectives, service users were purposively sampled based on pre-post changes in social inclusion and personal recovery, with participants randomly selected from the top and bottom 20% ('high' and 'low' responders).Four themes emerged: (1) adaptable settings and intervention flexibility; (2) 'active ingredients' such as mutuality, reciprocity, and role-modelling; (3) positive intra-personal, interpersonal, and behavioural outcomes; and (4) barriers, including mismatches, unmet expectations, unclear boundaries and challenges to continuity.The study highlights shared relational elements of peer support alongside context-specific adaptations.Findings reinforce its value as a complementary, personcentred service with global relevance, while pointing to challenges including improving matching, reducing dropout, and clarifying expectations.Site-specific aspects are discussed, offering insights for global implementation. Impact statementUnderstanding how peer support is experienced across high-, middle-, and low-income settings is crucial for strengthening recovery-oriented mental health care globally.This study provides cross-site findings from the UPSIDES Trial, presenting the core mechanisms of peer support that matter to service users, while highlighting the importance of flexibility in responding to individual, cultural, and resource-related needs.By identifying practical challenges such as matching, unmet expectations, and discontinuity, the findings offer guidance for policymakers, programme developers, and clinical leaders seeking to implement or scale peer-support services.Grounded in diverse service-user experiences, findings shed light on ways to promote more adaptable, person-centred, and contextually responsive mental health systems worldwide.
Goldfarb et al. (Fri,) studied this question.