Why peer-led crisis plan practice does - and does not - transform psychiatric ward culture: a realist-informed qualitative study from Japan.

Background: Japan's psychiatric inpatient environment - characterized by the world's highest per-capita psychiatric bed rate, entrenched coercive care, and persistent physical restraint - has resisted policy reform. Crisis Plans (CP) are meant to be authored by the service users who may experience a crisis, but in practice, clinicians often write them instead. Peer-led CP practice has been proposed as a catalyst for recovery-oriented transformation, yet how it actually generates organizational change remains theoretically underspecified. Aim: This study aimed to identify the generative mechanisms and structural conditions through which peer-led CP practice transforms psychiatric ward culture in Japan. Methods: We interviewed thirteen nurses, managers, and peer support workers (PSWs) at two psychiatric hospitals. An integrated qualitative design was used: interview data were first analysed inductively using the Modified Grounded Theory Approach (M-GTA), then re-examined through Realist Evaluation (RE) to identify causal mechanisms. Archer's morphogenetic approach was applied to interpret how organizational structures change or persist. Results: Broad change in ward relationships developed when three mechanisms operated together: the hospital, rather than the individual nurse, taking responsibility for clinical risk (M1); the staged introduction of PSWs' lived-experience knowledge via a bridging staff member (M2); and staff letting go of the assumption that their job is to manage the person, allowing the peer-led return of CP authorship to the service user (M3). When these operated together, roles reversed: service users came to ask for care, and professionals responded. In the negative case (a site without PSWs), CP practice produced only individual-level change that was ultimately reabsorbed into existing practice. Conclusion: PSWs occupy a structurally distinctive position: standing between the ward's existing conditions and the processes that change them, they turn structural constraint into a driver of change. It appears to be the maintained tension and ongoing disagreement between professional and lived-experience perspectives that sustains this change and the self-questioning on which durable transformation depends.