Toxicological profiles in adolescent suicide before and after COVID-19: A forensic autopsy study of the involvement of over-the-counter medications and sex differences in urban Japan.

Adolescent suicide remains a major public health concern, with recent increases observed, particularly among females in Japan. However, the toxicological characteristics in forensic settings have not yet been sufficiently described. This study examined the toxicological patterns in adolescent suicide cases before and after the onset of the coronavirus disease 2019 (COVID-19) pandemic, using forensic autopsy data from three institutions in metropolitan Japan (2015-2024). A total of 41 cases (10 males, 31 females) were included in the study. Toxicological findings were compared between the pre-2020 (n = 9) and post-2020 (n = 32) periods, with additional analyses by sex. Over-the-counter (OTC) medication-related components, excluding caffeine, were detected in 33.3% of pre-2020 cases and 53.1% of post-2020 cases. Relevant drugs other than caffeine were detected in 44.4% and 68.8% of cases in the two periods, respectively. Overall, relevant drug detection was more frequent among females than males. Benzodiazepines and Z-drugs were detected predominantly in the post-2020 period. No illicit drugs were identified. These findings indicate that OTC-related components were commonly detected among adolescent suicide decedents undergoing forensic autopsy and suggest possible sex-related differences in toxicological patterns. Comprehensive toxicological assessment may provide additional information for understanding drug exposure associated with adolescent suicide.