Do suicide rates in children and adolescents change during school closure in Japan? The acute effect of the first wave of COVID-19 pandemic on child and adolescent mental health

Background: The coronavirus disease 2019 (COVID-19) has severely impacted the lives of children and adolescents. School closure, one of the critical changes during the first COVID-19 wave, caused decreases in social contacts and increases in family time for children and adolescents. This can have both positive and negative influences on suicide, which is one of the robust mental health outcomes. However, the impact of the COVID-19 crisis on children and adolescents in terms of suicide is unknown. Objective: This study investigates the acute effect of the first wave of the COVID-19 pandemic on suicide among children and adolescents during school closure in Japan. Data: Total number of suicides per month among children and adolescents under 20 years old between January 2018 and May 2020. Methods: Poisson regression was used to examine whether suicide increased or decreased during school closure, which spanned from March to May 2020, compared with the same period in 2018 and 2019. Robustness check was conducted using all data from January 2018 to May 2020. Negative binomial regression, a model with overdispersion, was also performed. Results: We found no significant change in suicide rates during the school closure (incidence rate ratio (IRR) = 1.15, 95% confidence interval (CI): 0.81 to 1.64). We found the main effect of month, that is, suicides significantly increased suicides in May (IRR: 1.34, 95% CI: 1.01 to 1.78) compared to March, but the interaction terms of month and school closure were not significant (p > 0.1). Conclusions: As preliminary findings, this study suggests that the first wave of the COVID-19 pandemic has not significantly affected suicide rates among children and adolescents during the school closure in Japan.