Long-term outcomes of assertive community treatment in Japan: 7-year follow-up of a randomized controlled trial

Within the context of community care, assertive community treatment (ACT) targeting individuals with severe mental disorders is typically a prolonged endeavor. Despite its extended nature, evidence on the long-term effects of ACT remains limited. This study aimed to assess the long-term effects of ACT services in Japan over 7 years by comparing readmission outcomes between the ACT and treatment-as-usual (TAU) groups.

This study traced participants from a prior randomized controlled trial (RCT) examining the short-term effects of ACT program in Japan. We assessed their readmission experiences, including the frequency and length (days) of readmissions over 7 years through medical record review. Multivariable analyses were conducted to examine outcomes by group.

Of the 63 participants tracked for 7 years of follow-up (ACT group = 34, TAU group = 29), there were no significant group differences in readmission rate (TAU = 79% vs. ACT = 53%; odds ratio = 0.41, 95% CI = 0.12 to 1.35, p = 0.144) or cumulative days of hospitalization (Β = -75.66, 95% CI = -184.41 to 33.09, p = 0.173). However, the ACT group had significantly fewer hospitalizations (Β = - 1.03, 95% CI = - 1.97 to - 0.10, p = 0.030) than the TAU group. In particular, readmissions in the ACT group substantially decreased at 2 years after initial randomization.

In the Japanese medical landscape, an ACT program for individuals with severe mental illness might help mitigate the frequency of readmission compared with TAU over the long term. In particular, the pronounced benefits of the ACT program appear to emerge approximately 2 years after the start of ACT services. Future research in different countries is needed to confirm the findings of this study, particularly the timing at which the long-term effects of ACT services emerge for various outcomes.

The trial was retrospectively registered on 5 August 2025 with the Japan Registry of Clinical Trials (Registration number: jRCT1030250281).