Suicidal behavior among forensic psychiatric patients in Japan: Risk factors and implications for treatment

In Japan, the Medical Treatment and Supervision Act (MTSA) was enacted in 2005 to provide intensive interventions aimed at reintegrating forensic psychiatric patients into society. However, these individuals face challenges with social reintegration and have an elevated risk of suicide. Therefore, identifying the risk factors for suicide among forensic psychiatric patients is essential. We compiled an extensive database spanning 12 years of data on Japanese forensic outpatients. Using a generalized linear model (GLM), we explored the relationship between suicidal behaviors-both attempted and completed suicides-and several variables, including outpatient pathways defined by law, histories of psychiatric outpatient/inpatient treatment, diagnoses of schizophrenia or mood disorders, types of crimes committed, and the types of victims involved. Our analysis included data from 2,263 Japanese forensic outpatients. Suicidal behaviors were observed in 6.9% of patients, with 1.5% completing suicide. Risk factors for suicidal behavior included being a direct outpatient (odds ratio [OR] = 1.63, 95% confidence interval [CI]: 1.14-2.34), having a history of outpatient treatment (OR = 1.92, 95% CI: 1.07-3.48), and being arrested for arson (OR = 2.24, 95% CI: 1.33-3.76). Conversely, a diagnosis of schizophrenia was associated with a reduced risk of suicidal behavior (OR = 0.61, 95% CI: 0.39-0.95). Forensic psychiatric patients are at a higher risk of suicide compared to the general population. It is essential to account for both risk and protective factors when planning interventions for these individuals.