Trends in the prevalence of psychological distress and the use of mental health services from 2007 to 2016 in Japan

Background: Little is known regarding trends of psychological distress and use of mental health services in Japan during recent years. Methods: This study examined trends in severe and moderate psychological distress and the use of mental health services among adults (≥18 years old), using the Comprehensive Survey of Living Conditions in Japan from 2007, 2010, 2013, and 2016 (Total N = 2,159,005, all survey years combined). We defined a score of ≥13 on Kessler Psychological Distress Scale (K6) as severe distress and a K6 score between 5 and 12 as moderate distress. Age- and sex-specific trends of psychological distress and the use of mental health services were also examined. Results: As compared with 2007, those with severe distress slightly increased in 2016 (4.01%–4.15%, p = 0.02) while those with moderate distress remained mostly unchanged (24.61%–24.69%, p = 0.61). The use of mental health services steadily increased in this decade for both with severe distress (11.95%–15.76%, p < 0.01) and with moderate distress (2.60%–3.56%, p < 0.01). The prevalence of severe distress among women aged 25–29 years old was highest in 2016 among all the age groups although the use of mental health services was not particularly high among women in this age group. Limitations: Cross-sectional nature of the data did not allow us to examine the causal relationship between psychological distress and the use of mental health services. Conclusions: In spite of an observed increase in the use of mental health services, the prevalence of psychological distress slightly increased. Further studies are necessary to identify sources of treatment gap especially for vulnerable demographic subgroups.