Exploring factors associated with increased suicides during the COVID-19 pandemic in Japan: A study using data from postmortem examinations conducted in an urban area.

Aim: The purpose of this study is to examine factors associated with increased suicide deaths during the coronavirus disease 2019 (COVID-19) pandemic in Japan using primary data from postmortem examinations.

Methods: We explored factors associated with suicides that occurred during the COVID-19 pandemic (February 2020 to December 2021) using data from 115 postmortem examinations of suicides that occurred in one city in the Kanto region between January 2017 and December 2021.

Results: Multivariate analysis using graphical modelling and logistic regression analysis showed that both female sex (adjusted odds ratio: 3.732; 95% confidence interval: 1.044-13.345) and multiple mental disorders (adjusted odds ratio: 7.344; 95% confidence interval: 1.316-40.987) were significantly associated with suicide during the COVID-19 pandemic among the young age group (39 years or under).

Conclusion: The study results suggest that in addition to the factor of female sex previously identified, morbidity due to multiple mental disorders may be associated with the increased suicides in Japan during the COVID-19 pandemic. Furthermore, this study presented the new methodological possibility of analyzing background factors of suicide using postmortem examination data. In preparation for similar emergencies in the future, it is necessary to establish a system that provides care for multiple mental disorders and a continuous suicide-monitoring system that combines methods such as psychological autopsies with other methods.