Previous research has shown that forensic psychiatric treatment reduces reoffending, rehospitalization and premature mortality. Treatment outcome varies with diagnosis, but little is known about the influence of sex, psychosocial adjustment and aftercare.
To assess these variables, we interviewed male and female patients discharged from three psychiatric security hospitals in Germany in the years 2010–2017. Participants were interviewed at discharge (n = 609) and 1 year later (n = 366) about reoffending, readmissions, substance use and psychosocial adjustment. Among patients with substance use disorder (SUD), 14% reoffended, 20% were re‐hospitalized and 60% maintained abstinence. Among patients with severe mental disorder, 5% reoffended and 13% were re‐hospitalized. Significant sex differences were found in offenders with SUD. The results suggest that sociodemographic and disorder‐related risk factors are associated with treatment success and that female patients with SUD might need a specific treatment approach. Sex‐specific aspects, diagnosis and psychosocial adjustment should be considered in forensic psychiatric treatment and risk assessment.