<p>This study examined whether overall and domain-specific self-disclosure to peers at baseline was prospectively associated with changes in personal recovery over one-year among community-dwelling adults with mental disorders in Japan. A longitudinal questionnaire survey was conducted among adults with mental disorders. Self-disclosure was assessed using the Self-Disclosure Scale for People with Mental Illness, and personal recovery was measured with the Japanese version of the Recovery Assessment Scale. Linear mixed-effects models were used to examine recovery at baseline and at one-year follow-up as a continuous outcome, including time, baseline self-disclosure, and their interaction, with random intercepts for participants. Models were adjusted for age, sex, and service utilization. Fifty-four participants (mean age = 41.1 years; 48% female) responded to both the baseline and follow-up surveys. Mean recovery scores did not change significantly over one year. In domain-specific analyses, greater baseline self-disclosure about mental illness and psychiatric disability was associated with less positive changes in recovery over one year (Estimate = − 4.162, SE = 1.589, 95% CI [− 7.316, − 1.008], <i>p</i> = 0.010). Conversely, no significant time-by-disclosure interactions were observed for the other disclosure domains (life conditions, own strengths, and experiences of distress). Among community-dwelling people with mental disorders, baseline self-disclosure about mental illness and psychiatric disability to peers was associated with less positive changes in personal recovery over one year, whereas the other disclosure domains were not significantly associated with changes over time. These findings suggest that disclosure about mental illness and psychiatric disability in peer contexts may have context-dependent implications. Moreover, they underscore the importance of fostering safe and supportive peer environments that respond constructively to such disclosures within recovery-oriented care.</p>