Depression, risk factors, and coping strategies in the context of social dislocations resulting from the second wave of COVID-19 in Japan

BACKGROUND: Social dislocations resulting from coronavirus disease 2019 (COVID-19) pandemic have been prolonged, which has led to general population social suppression. The present study aimed to reveal risk factors associated with mental health problems and suggest concrete coping strategies in the context of COVID-19. METHODS: A web-based survey was conducted in July when Japan was experiencing a second wave of COVID-19. Demographics, Patient Health Questionnaire-9 (PHQ-9), state anger, anger control, and the Brief Coping Orientation to Problems Experienced were measured. Multivariate logistic regression analysis on PHQ-9 scores by set variables was conducted. RESULTS: The participants were 2708 individuals, and 18.35% of them were depressed. Logistic regression analysis showed that in the order of odds ratios (ORs), underlying disease (OR = 1.96, 95% confidence interval (CI) = 1.32–2.92), not working (OR = 1.85, CI = 1.22–2.80), negative economic impact (OR = 1.33, CI = 1.01–1.77), state anger (OR = 1.17, CI = 1.14–1.21), anger control (OR = 1.08, CI = 1.04–1.13), age (OR = 0.97, CI = 0.96–0.98), high income (OR = 0.45, CI = 0.25–0.80), and being married (OR = 0.53, CI = 0.38–0.74) were predictors of depressive symptoms. Regarding coping strategies, planning (OR = 0.84, CI = 0.74–0.94), use of instrumental support (OR = 0.85, CI = 0.76–0.95), denial (OR = 0.88, CI = 0.77–0.99), behavioural disengagement (OR = 1.28, CI = 1.13–1.44), and self-blame (OR = 1.47, CI = 1.31–1.65) were associated with probable depression. CONCLUSIONS: During prolonged psychological distress caused by COVID-19 pandemic, the prevalence of depressive symptoms in Japan was two to nine times as high as before the COVID-19 pandemic, even though Japan was not a lockdown country. Although some coping strategies were useful for maintaining mental health, such as developing ways, alone or with others, to address or avoid social dislocations, the influence of demographics was more powerful than these coping strategies, and medical treatments are needed for high-risk individuals. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-021-03047-y.