Abstract
BACKGROUND: Integration of voluntary and statutory mental health services may address gaps in mental health care. The Community Mental Health Framework for Adults and Older Adults 2019 provided impetus for integration within England. It was unknown how, why, or under what circumstances integration would occur. METHODS: A realist evaluation of Framework implementation in Somerset was undertaken. The extent of change, and how, why and under what circumstances change occurred were evaluated. Embedded researchers collected observational and interview data, and reviewed internal records. Realist qualitative analysis created and tested a programme theory exploring the extent, cause, and impact of change. RESULTS: Services worked together to create an integrated mental health service using a cultural change model: new language prompted new ways of thinking and working. Programme theory testing demonstrated good extent of change. Voluntary sector integration helped address treatment gaps: all service users were offered a service. Mechanisms of change included: new language, relationship building, flexible working, and valuing voluntary sector services. Contextual factors affecting the extent of change included: balances of power, rigidity of statutory services, and trusting management. CONCLUSIONS: Integrating services using a culture change model addresses gaps in mental health care. Optimal implementation requires addressing contextual barriers.