Assessment of suicide in Japan during the COVID-19 pandemic vs previous years

Importance  There are concerns that suicide rates may have increased during the coronavirus disease 2019 (COVID-19) pandemic.

Objective  To assess whether suicide rates in Japan increased in April through November 2020 compared with previous years.

Design, Setting, and Participants  This cross-sectional study used national data obtained from the Ministry of Health, Labor and Welfare from 2016 to 2020 on the monthly number of individuals who died of suicide in Japan from January to November of 2016 to 2020.

Exposure  2020 vs previous years.

Main Outcomes and Measures  The main outcome was monthly suicide rates, calculated as the number of individuals who died of suicide divided by the total population. A difference-in-difference regression model was used to estimate the change in monthly suicide rates in April to November 2020 vs these months in 2016 to 2019.

Results  Analyses included 90 048 individuals (61 366 [68.1%] men) who died of suicide from 2016 to 2020. The difference-in-difference analysis of men showed that there was no increase in suicide rates from April through September 2020 compared with these months in 2016 to 2019, but that suicide rates were increased in October (difference-in-difference, 0.40 [95% CI, 0.14 to 0.67] suicide deaths per 100 000 population) and November (difference-in-difference, 0.34 [95% CI, 0.07 to 0.60] suicide deaths per 100 000 population). Among women, suicide rates in 2020 compared with 2016 to 2019 increased in July (difference-in-difference, 0.24 [95% CI, 0.09 to 0.38] suicide deaths per 100 000 population), August (difference-in-difference, 0.30 [95% CI, 0.16 to 0.45] suicide deaths per 100 000 population), September (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population), October (difference-in-difference, 0.62 [95% CI, 0.48 to 0.77] suicide deaths per 100 000 population), and November (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population). In secondary analyses in which the suicide rates of 2020 were compared with the expected rates based on trends from 2011 to 2019, the increases in suicide rates were most pronounced among men aged younger than 30 years (eg, November: observed vs expected rate ratio [RR], 1.48 [95% CI, 1.26-1.71]) and women aged younger than 30 years (eg, October: observed vs expected RR, 2.14 [95% CI, 1.76 to 2.52]) and 30 to 49 years (eg, October: observed vs expected RR, 2.30 [95% CI, 2.01 to 2.58]).

Conclusions and Relevance  These findings suggest that compared with previous years, suicide rates in Japan in 2020 increased in October and November for men and in July through November for women.