Previous surveys on depression in China focused on prevalence estimates without providing a detailed epidemiological profile.

Face-to-face household interviews were conducted with a multi-stage household probability sample of 2633 adults (age ⩾18 years) in Beijing and 2568 in Shanghai between November 2001 and February 2002. The World Health Organization Composite International Diagnostic Interview (CIDI) was used to assess major depressive episode (MDE) according to Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria.

The lifetime prevalence and 1-year prevalence estimates of DSM-IV/CIDI MDE were 3.6% [95% confidence interval (CI) 2.8–4.4%] and 1.8% (95% CI 1.2–2.4%) respectively. No significant gender difference was found in these estimates. Respondents born in 1967 or later were at elevated lifetime risk compared with respondents born in earlier cohorts. The mean age of onset was 30.3 years. Among those reporting 1-year MDE, 15.7, 51.8, 25.3 and 6.4% reported mild, moderate, severe and very severe symptoms respectively; 4.8, 2.6 and 3.2% reported suicidal ideation, plans, and recent attempts in the same year respectively. Respondents with 1-year MDE reported a mean of 27.5 days out of role owing to their depression in the year before interview. Significant co-morbidity was found between MDE and other mental disorders [odds ratio (OR) 22.0] and chronic physical disorders (OR 3.2). Only 22.7% of respondents with 1-year MDE sought treatment.

The low prevalence and insignificant gender difference, but not patterns of onset, course, co-morbidity, and impairment, distinguish the epidemiological profile of MDE in metropolitan China from those in other countries.