Overdose dominates adolescent self-harm in Japan’s new national registry

Researchers analyzing the Japan Registry of Self-Harm and Suicide Attempts, known as JA-RSA, found that medication overdose was by far the most common method among young people, accounting for 70.1 percent of registered cases, and that most of these episodes involved over-the-counter medications rather than prescribed drugs.

The study, published in Child and Adolescent Psychiatry and Mental Health, drew on cases registered across 44 critical care medical centers in Japan between December 2022 and December 2023. From 1,987 total registered cases, the researchers retrospectively analyzed 241 adolescents and young adults ranging from elementary school students through college students. The registry collected demographic characteristics, methods of self-harm, psychiatric history and clinical outcomes for each case.

Two groups dominated the data. High school adolescents, numbering 80, and college-age young adults, numbering 93, together made up 71.8 percent of the analyzed cases. The median age was 17 years, and females comprised 71.3 percent of the cohort. Nearly half of all individuals, 46.5 percent, had a documented history of prior self-harm or suicide attempts, a figure the authors highlight as central to prevention planning.

The registry’s design reflects a difficult methodological reality. Because suicidal intent could not be reliably determined in all nonfatal cases, the researchers analyzed nonfatal self-harm and suicide attempts collectively rather than trying to separate them, and then compared this combined group with individuals who died by suicide. This approach preserves the data while acknowledging the limits of what retrospective registry records can establish about intent.

That comparison revealed stark contrasts between those who survived and those who died. Individuals who died by suicide were more likely to be male, a difference that reached statistical significance at p = 0.038, and they were far more likely to use highly lethal methods such as hanging or jumping, at p < 0.001. Overdose, by contrast, was significantly more common among those who survived, also at p < 0.001.

Help-seeking patterns also differed between the groups. Those who died by suicide had lower rates of recent psychiatric consultation than survivors, and the documented prevalence of prior self-harm or suicide attempts among suicide deaths was low, a difference significant at p = 0.001.

The context behind the study is a worrying demographic shift in Japanese suicide statistics. Although overall suicide mortality in Japan has declined over time, rates among young people have increased, which the authors cite as the motivation for building a clearer understanding of the characteristics of self-harm and suicide attempts in this age group. The JA-RSA registry was established to provide exactly that kind of nationwide surveillance.

Based on the patterns observed, the researchers conclude that self-harm among adolescents and young adults in Japan is characterized by a predominance of female adolescents and medication overdose. They suggest that preventive strategies may require follow-up care after an episode, environmental safety measures, and school- and community-based mental health interventions, all supported by continued national surveillance through the JA-RSA registry.

The findings carry practical implications for emergency and critical care services. Because overdose involving over-the-counter medications is the dominant method among survivors, environmental measures affecting medication access may be relevant, and the high proportion of individuals with prior self-harm suggests that follow-up after a first episode is a key intervention point. The registry’s coverage of 44 critical care centers gives the data broad national scope, although the analysis is retrospective and limited to cases that reached these medical facilities.

The study is published as open access research, and the authors emphasize that continued data collection through JA-RSA will be needed to track whether these patterns change over time and to evaluate whether prevention strategies targeting follow-up care, medication safety and school-based mental health support reduce the burden of self-harm among Japan’s young people.

Subject of Research: Characteristics of self-harm and suicide attempts among adolescents and young adults in Japan, based on a national registry analysis.

Article Title: 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)

Article References: Maeda, Y., Toida, C., Uchida, M., Akita, M., Kamijo, H., & Imamura, H. (2026). 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). Child and Adolescent Psychiatry and Mental Health. https://doi.org/10.1186/s13034-026-01191-5

Image Credits: AI Generated

DOI: 10.1186/s13034-026-01191-5

Keywords: self-harm, suicide attempts, adolescents, young adults, Japan, JA-RSA registry, overdose, suicide prevention, psychiatric consultation, critical care centers, public health surveillance, mental health