Suicide rates higher than expected during second wave of COVID-19 pandemic in Japan

Suicide rates during the second wave of the COVID-19 pandemic in Japan exceeded estimated numbers across a multitude of personal, socioeconomic and social factors, according to a cross-sectional study published in JAMA Network Open.

“Suicide rates in different countries seem to have been constant since the COVID-19 pandemic onset; in contrast, Japan’s statistics have indicated an increasing trend,” Masahide Koda, PhD, of the department of psychiatry and faculty of medicine at the University of Miyazaki, in Japan, and colleagues wrote.

“Worldwide, suicide rates tend to be higher in men than women. However, from July 2020 to October 2020 (the second wave of the COVID-19 pandemic), the rate of increase in suicide rates was higher among Japanese women than men. Therefore, the COVID-19 pandemic may be associated with changes in the reasons for suicide among the Japanese population.”

Koda and colleagues sought to ascertain which specific reasons for suicide possessed higher rates than the expected number of deaths for that reason during the pandemic.

The researchers culled data from January 2020 to May 2021 from Japan’s Ministry of Health, Labor, and Welfare, targeting only those deaths by suicide for which the reason was known, broken down into seven categories (family, health, economy, work, relationship, school, others [eg copycat suicide] and unknown), and 52 subcategories, as established by the 2007 Countermeasures Basic Law. Only the unknown category was excluded due to lack of information.

To analyze each specific category, Koda and colleagues compared data from the initial research period with data from December 2014 to June 2020. For subcategory analysis, they compared data from January 2020 to May 2021 with data from January 2019 to June 2020. They employed a quasi-Poisson regression model to estimate the expected number of monthly suicide deaths, which were categorized for men, women, both genders combined, all cases, each category and each separate subcategory.

A total of 29,938 suicides were identified (9,984 women; 3.7% aged 20 years or younger; 10.5% aged 80 or older). Of those, 21,027 suicides had a reason identified; 35.3% were women.

Results showed that all six categories indicated an excess rate of suicide for both men and women, excepting school for men. The highest excess rate for all cases occurred in October 2020. For men, the highest rate was 24.3% in the “other” category in August 2020. For women, the highest rate was 85.7% for “school” in August 2020.

“Overall, the excess trends for suicides in our study concur with those in prior research,” Koda and colleagues wrote. “We observed excess suicide rates around July 2020, during the onset of the second COVID-19 wave in Japan; this wave may have been associated with a diminished sense of social bonding.”