Psychological distress and mental health service use trends in Japan (2013-2022): Focusing on the change before and after the COVID-19 pandemic.

This study investigated trends in psychological distress and mental health service use in Japan before and after the COVID-19 pandemic using nationally representative data from the Comprehensive Survey of Living Conditions (2013-2022). Psychological distress was assessed using the Japanese version of the Kessler 6 Scale, with scores of 5-12 indicating moderate distress and scores of ≥13 indicating high distress. Mental health service use was defined as regular visits to hospitals or clinics for depression or other psychological disorders. Analysis of data from 1,765,102 participants revealed that while the prevalence of moderate distress decreased from 24.9 % in 2019 to 21.8 % in 2022, the prevalence of high distress increased from 4.7 % to 5.0 % over the same period. Notably, increases in high distress were most prominent among aged 35-49 population. Cross-sectionally, women aged 26-34 showed highest prevalence of high distress (7.6 %). Additionally, mental health service use rose markedly, especially among young adults with high distress, with women consistently reporting higher distress and service utilization than men. These findings suggest a polarization in psychological distress in Japan, with a decline in moderate symptoms concurrent with a rise in severe distress, highlighting emerging gaps in mental health care. The results underscore the need for targeted interventions and the expansion of accessible, diverse mental health services to address unmet needs, particularly among vulnerable subgroups including young women and middle-aged population.