Previous research has indicated the suicide rate has not increased in high-income countries due to the pandemic, but a recent analysis in Japan shows excess suicide deaths in women, but not men between July-September 2020.
A team, led by Haruka Sakamoto, MD, MPH, Department of Health Policy and Management, Keio University, assessed whether suicide rates in Japan increased between April and November 2020 compared to the suicide rates in 2019.
How They Analyzed The Data
In the cross-sectional study, the investigators used national data collected by the Ministry of Health, Labor, and Welfare between 2016-2020 on the monthly number of individuals who died of suicide in Japan between January-November of 2016-2020.
The investigators sought main outcomes of monthly suicide rates, calculated as the number of individuals who died of suicide dived by the total population. They used a difference-in-difference regression model to estimate the change in monthly suicide rates during the study period in 2020 compared to the same time period in 2016-2019.
Overall, there were 90,048 individuals who died of suicide between 2016-2020 included in the analysis, 68.1% were males.
In the difference-in-difference analysis of the just the males in the study, the researchers found no increase in suicide rates in 2020 compared to 2016-2019 between April and September. However, they did find an increase strictly in October (difference-in-difference, 0.40; 95% CI, 0.14-0.67; suicide deaths per 100,000 population) and November (difference-in-difference, 0.34; 95% CI, 0.07-0.60 suicide deaths per 100,000 population).
For women, the suicide rates in 2020 increased in July (difference-in-difference, 0.24; 95% CI, 0.09-0.38 suicide deaths per 100,000 population), August (difference-in-difference, 0.30; 95% CI, 0.16-0.45 suicide deaths per 100,000 population), September (difference-in-difference, 0.29; 95% CI, 0.15-0.44 suicide deaths per 100,000 population), October (difference-in-difference, 0.62; 95% CI, 0.48-0.77 suicide deaths per 100,000 population), and November (difference-in-difference, 0.29; 95% CI, 0.15-0.44 suicide deaths per 100,000 population).
After the researchers conducted a secondary analysis comparing 2020 suicide rates with the expected rates based on trends between 2011-2019, the team found the increases in suicide rates were most pronounced among males younger than 30 (November: observed vs expected RR, 1.48; 95% CI, 1.26-1.71) and women aged younger than 30 years (October: observed vs expected RR, 2.14; 95% CI, 1.76-2.52) and 30-49 years (October: observed vs expected RR, 2.30; 95% CI, 2.01-2.58).
“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,” the authors wrote.
Since the beginning of the pandemic there has been concerns over the impact of mitigation measures like social distancing and shelter-in-place restrictions could have on the collective mental health of the population.
The study, “Assessment of Suicide in Japan During the COVID-19 Pandemic vs Previous Years,” was published online in JAMA Network Open.