[Successful Implementation of Peer Support for People with Severe Mental Illness in Germany: a Theory of Change Approach]. / Eine Theory of Change zur erfolgreichen Implementierung von Peer-Begleitung für Menschen mit schweren psychischen Erkrankungen in Deutschland.

OBJECTIVE: Peer support is an established intervention in which people with mental illness receive support by trained peer support workers who have already overcome a mental health crisis. The implementation of peer support is complex due to interacting factors and can be achieved through the participatory Theory of Change method. Aim of this study is to develop a cross-site Theory of Change for the sustainable implementation of UPSIDES peer support in Germany. METHODS: Based on site-specific Theories of Change workshops from Ulm and Hamburg in which 47 participants took part, a cross-site Theory of Change was designed and verified in three follow-up workshops with 12 participants. Participants' professional and experiential backgrounds were diverse, including peer support workers, hospital directors and managers, mental health professionals (psychiatrists, psychotherapists, nurses), and researchers. RESULTS: The first pathway of the cross-site Theory of Change focuses on the training of peer support workers, whereas the second pathway emphasizes recognition and integration by mental health institutions and professionals. The third pathway specifies the building of a cross-professional care network to integrate various peer support services. Procedures to approach prospective peer clients are depicted in the fourth pathway. The fifth path addresses the clarification of the role description of peer support workers and the implementation in other institutions through cooperation. DISCUSSION: Many of the identified implementation steps have been validated in comparable studies. The development of this Theory of Change by bringing together multiple perspectives of key stakeholders is an important basis for the sustainable implementation of UPSIDES peer support. Furthermore, it may serve as a blueprint for the implementation of similar interventions to advance scaling-up of evidence-based user-led and recovery-oriented interventions. CONCLUSION: The Theory of Change approach is a well-accepted and feasible method, which can be recommended for the implementation of complex interventions such as UPSIDES peer support.