Self-harm and suicide attempts among adolescents and young adults in Japan: a registry-based analysis of the Japan Registry of Self-Harm and Suicide Attempts (JA-RSA)

Aim Although overall suicide mortality in Japan has declined, rates among young people have increased. Understanding the characteristics of self-harm and suicide attempts among adolescents and young adults is important for prevention. This study analyzed data from the Japan Registry of Self-Harm and Suicide Attempts (JA-RSA), a nationwide registry in Japan. Methods We retrospectively analyzed 241 adolescents and young adults from elementary school through college, selected from 1,987 cases registered across 44 critical care medical centers between December 2022 and December 2023. Demographic characteristics, methods of self-harm, psychiatric history, and clinical outcomes were evaluated. Because suicidal intent could not be reliably determined in all nonfatal cases, nonfatal self-harm and suicide attempts were analyzed collectively and compared with suicide deaths. Results Adolescents in high school ( n = 80) and young adults in college ( n = 93) accounted for 71.8% of cases. Females comprised 71.3%, and the median age was 17 years. Overdose was the most common method (70.1%), mainly involving over-the-counter medications. Nearly half (46.5%) had a history of prior self-harm or suicide attempts. Individuals who died by suicide were more likely to be male ( p = 0.038) and to use highly lethal methods such as hanging or jumping ( p < 0.001), whereas overdose was more common among those who survived ( p < 0.001). They also had lower rates of recent psychiatric consultation and a low documented prevalence of prior self-harm or suicide attempts ( p = 0.001). Conclusions Self-harm among adolescents and young adults in Japan is characterized by a predominance of female adolescents and medication overdose. Preventive strategies may require follow-up care, environmental safety measures, and school- and community-based mental health interventions, supported by continued national surveillance through JA-RSA.