Changing trends in the prevalence of common mental disorders in Taiwan: a 20-year repeated cross-sectional survey

Summary Background Macrosocial changes might affect mental health. We investigated whether the prevalence of common mental disorders (CMDs) changed over a 20-year period of industrialisation in Taiwan. Methods We used the 12-item Chinese Health Questionnaire to assess mental status of Taiwanese adults in 1990, 1995, 2000, 2005, and 2010. Respondents with scores of 3 or higher were classified as having probable CMDs. We assessed trends of probable CMDs with the Cochran-Armitage test and their risk factors (sex, age, marital status, educational level, employment status, and physical health) with multivariable logistic regression. The trends were compared with national rates of unemployment, divorce, and suicide. Findings Of 10 548 respondents, 9079 (86·1%) completed questionnaires. The prevalence of probable CMDs doubled from 11·5% in 1990 to 23·8% in 2010 (time trend p