Real-World Effectiveness of the Peer-Led Honest, Open, Proud Programme for Self-Stigma Among Adults With Mental Illness: A Pragmatic, Multicentre, Randomised Controlled Trial

Background: The stigma of mental illness is a key barrier to recovery, help-seeking and social inclusion of people with mental disorders. Faced with stigma and discrimination, many struggle with the decision whether to disclose their condition to others. Honest, Open, Proud (HOP) is a peer-led group programme that supports participants with disclosure decisions. This study examined HOP's real-world effectiveness to reduce self-stigma and to improve secondary clinical and social outcomes as well as its cost-effectiveness. Methods: In this open-label, pragmatic parallel 2:1-randomised trial, we included working-age adults with mental illness across nine sites in Germany, recruited in clinical and community settings. Participants were randomly assigned to HOP and treatment as usual (TAU, 2/3), or to TAU alone (1/3). Outcomes were assessed by self-report pre (baseline), post (6 weeks) and at 6-month follow-up. The primary endpoint was self-stigma at 6 weeks. Intervention effects were analysed by intention-to-treat analysis. The trial was pre-registered on DRKS (https://drks.de/search/en/trial/DRKS00033314). Findings: From February to November 2024, 457 participants (mean age 42 years, 66% female, 92% German born) were included in the trial; 306 were randomised to HOP and TAU, and 151 to TAU alone. Compared to TAU, HOP participants showed significantly less self-stigma at week 6 (-1.83, 95%-CI -2.96 to -0.70, d = -0.24, p = 0.0015) and at 6-month follow-up (-1.20, 95%-CI -2.36 to -0.05, d = -0.16, p = 0.042). In terms of secondary outcomes, HOP had significant positive effects on stigma stress, depressive symptoms, help-seeking intentions, quality of life, recovery, shame, and social inclusion at 6 weeks. In an economic evaluation HOP was cost-effective in terms of quality of life gains. There were no project-related adverse events. Interpretation: HOP effectively reduces self-stigma among adults under real-world conditions and should be offered in addition to usual care in clinical and community settings. Funding: Federal Department of Health, Germany (2523FSB22A, 2523FSB22B).