ABSTRACT:
This study was developed through a collaboration between Yale University (USA) and State University of Campinas (Brazil), aiming to adapt and implement Peer Support (PS) within public community mental health services in Campinas, São Paulo, Brazil. Although PS is an internationally recognized, recovery-oriented practice, defined as support provided by individuals with lived experience of mental distress to others in similar situations1-2, its implementation in Brazil remains incipient3-4. This gap highlights the limited availability of evidence-based practices for people experiencing mental distress within public health systems. Participatory and context-sensitive approaches, such as Theory of Change (ToC), guided workshops integrated with implementation science, enable identification of cultural, institutional, and structural facilitators and barriers, while informing adaptations needed to ensure feasibility and relevance in local contexts5-6. By incorporating diverse stakeholder perspectives, these approaches support co-production of implementation strategies grounded in equity, social inclusion, and sustainability. The objective is to describe the pre-implementation phase of PS in public community mental health services, integrating ToC with the Consolidated Framework for Implementation Research (CFIR) and actively engaging stakeholders throughout the process. The ToC guided adaptation of a PS training program across six community-based mental health centers (CAPS III) in Campinas, including three intervention and three comparison sites. Between March and April 2024, four participatory workshops were conducted, including one consensus workshop, involving 23 co-researchers (13 with lived experience of mental distress and 10 with clinical experience in mental health). The workshops fostered knowledge co-production and enabled identification of expected outcomes, causal assumptions, and key contextual barriers and facilitators influencing PS implementation. Data generated during workshops and field notes were subjected to thematic analysis and organized according to CFIR domains. Findings demonstrated feasibility of PS in Brazil, highlighting potential to strengthen autonomy, reduce stigma, and support collaborative, inclusive, and sustainable community mental health practices nationwide implementation.