Research press release


Nature Human Behaviour

Mental health: Suicide rate changes in Japan during COVID-19 pandemic

日本の1か月当たりの自殺率は、新型コロナウイルス感染症(COVID-19)パンデミックの最初の5か月間で14%低下したが、第2波においては16%上昇したことを明らかにした論文が、Nature Human Behaviourに掲載される。今回の研究は、日本の全人口を対象としたデータセットについて報告しており、パンデミックの第2波の間には、女性、子ども、青年の自殺率に大きな増加が見られることも判明した。





Monthly suicide rates in Japan declined by 14% during the first five months of the COVID-19 pandemic, but increased by 16% in the second wave, shows a paper published in Nature Human Behaviour. The study, reporting a dataset covering the entire Japanese population, also finds that suicide rates saw greater increases among woman, children, and adolescents during the second wave of the pandemic.

There is concern about the psychological toll of the COVID-19 pandemic and its impacts on risk of suicide. Suicide is rarely due a single factor, and the reasons behind suicide prevalence are complex. Some national policies have led to reduced hours at work or school and/or the support of government subsidies, which may be associated with increased wellbeing. Yet, the threat of the disease may cause increased anxiety, and social distancing may lead to impaired relationships, increased loneliness, and restricted access to healthcare services. Some of these impacts are well-known risk factors for suicide. However, reliable, robust evidence of changes to suicide rates during the COVID-19 pandemic remains scarce.

Shohei Okamoto and Takanao Tanaka analysed city-level data covering the entire Japanese population—more than 120 million people—from November 2016 to October 2020. They found that monthly suicide rates declined by 14% during the initial five months of the pandemic (February to June 2020). Suicides among adults saw the greatest decline during the state of emergency (March 2020-April 2020), in both women (27%) and men (21%). The authors suggest that this may be linked to the provision of government subsidies, leading to a reduction in economic distress, and to a reduction in working hours and commuting time, leading to improvements in life satisfaction and mental health. Similarly, they suggest that school closures may have reduced psychological burdens on children and adolescents during the first wave.

During the second wave, from July to October, monthly suicide rates increased by 16%, with the magnitude of increase greater among females (37%) and among children and adolescents (49%). These findings show a marked difference from historical suicide patterns. Typically, the suicide rate among males in Japan is 2.3 times higher than that among females. In the second wave of the pandemic, the rate of increase in suicide mortality among females (37%) was about 5 times greater than the rate of increase among males (7%). Suicides among adult women who are married and not employed in wage labour increased during all pandemic periods. The authors argue that their results are consistent with recent studies that find that the crisis unevenly affects female-dominant industries and that stay-at-home orders magnify the burden of mothers.

The authors conclude that the pandemic may disproportionately affect the psychological health of women, children and adolescents. They recommend that future suicide prevention strategies should consider the factors that may have contributed to a reduction in suicides during the first wave and that effective prevention should be customised to particular groups.

doi: 10.1038/s41562-020-01042-z

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