Suicide attempt methods among patients referred for psychiatric evaluation at an advanced emergency and critical care medical center in Japan: associations with sex, age, and psychiatric diagnosis: a single-center retrospective study

Suicide attempts requiring emergency care provide a critical opportunity for psychiatric assessment and prevention. However, contemporary evidence from advanced emergency settings remains limited, particularly regarding how suicide attempt methods vary according to sex, age, and psychiatric diagnosis. This single-center retrospective study included 344 patients who were transported to an advanced emergency and critical care medical center after suicide attempts and were subsequently referred for psychiatric evaluation between April 2014 and March 2024. Psychiatric diagnoses and suicide attempt methods were classified using International Classification of Diseases, 10th Revision-based categories. The primary analyses examined sex-, age-, and diagnosis-specific patterns of suicide attempt methods. Secondary analyses compared high- and low-lethality attempts. Drug overdose was the most common method and was more frequent among female patients. Substance use disorders were more frequent among male patients. Age-specific analyses showed that drug overdose was more frequent among patients aged < 20 years, whereas pesticide poisoning was more frequent among patients aged ≥ 65 years. Diagnosis-specific analyses showed that jumping from height was more frequent among patients with schizophrenia and other psychotic disorders. In secondary analyses, patients in the high-lethality group were older, although high- and low-lethality attempts were observed across diagnostic categories. Suicide attempt methods among patients referred for psychiatric evaluation after emergency transport varied according to sex, age, and psychiatric diagnosis. These findings support post-attempt assessment in general hospital settings that integrates demographic and diagnostic context, the observed suicide attempt method, and medical severity rather than relying solely on categorized lethality.