Different trends in suicide rates among foreign residents in Japan and Japanese citizens during the COVID-19 pandemic.

Background: Suicide rates in Japan have increased during the COVID-19 pandemic, and foreign residents may be more vulnerable to mental stress during such crises. Therefore, we aimed to compare the trends in suicide rates during the COVID-19 pandemic between foreign residents and Japanese citizens.

Methods: Vital statistics of Japan data from January 1, 2016 to December 31, 2021 were used to calculate quarterly sex-specific suicide rates for foreign residents and Japanese citizens. An event-study analysis was conducted to evaluate whether suicide rates during the COVID-19 pandemic increased compared to pre-pandemic estimates; foreign residents and Japanese citizens were compared using difference-in-difference-in-differences estimates.

Results: Between 2016 and 2021, 1,431 foreign residents and 121,610 Japanese citizens died from suicide in Japan. Although the suicide rate for foreign residents was lower than that for Japanese citizens, Korean residents, who comprise approximately half of the foreign decedents, had largely higher suicide rates than Japanese citizens. The event-study analysis indicated that suicide rates increased among foreign residents for both men and women, and continued for men by the end of 2021. In Japanese citizens, after a decline in suicide rates in the second quarter of 2020, suicide rates increased both among men and women, and lasted for women until the fourth quarter of 2021. The difference-in-difference-in-differences analyses confirmed the initial decline in the second quarter of 2020 in suicide rate only in Japanese men and women, and the persistent increase through 2021 in foreign men.

Conclusions: We found differential trends in suicide rates between foreign and Japanese men and women during the COVID-19 pandemic featuring a persistent increase in foreign men. Suicide prevention measures should be focused on these high-risk subpopulations.