[Epidemiology of major depressive episodes among Chinese adults aged 30-79 years: data from the China Kadoorie Biobank].

OBJECTIVE: To examine the socio-demographic patterns on 12-month major depressive episodes (MDE) among Chinese adults aged 30-79 years. METHODS: Socio-demographic variables from half a million Chinese people aged 30-79 years in the China Kadoorie Biobank study during 2004-2008, were collected. For those showing signs of depression, an additional World Health Organization Composite International Diagnostic Interview-Short Form (CIDI-SF) was face to face administrated, to assess the MDE according to Diagnostic and Statistical Manual of Mental Disorder (DSM)- IV criteria. Chi squared and non-parametric tests were used to compare the differences between socio-demographic categories, depressive symptoms and help-seeking behaviors. Associations with MDE for socio-demographic variables were examined by logistic models. RESULTS: A total of 3 281(6.40‰) studied subjects showed an MDE in the preceding 12 months. Gender, marital status, occupation and household income were correlated with MDE. Somatization was common in Chinese MDE patients while symptoms as weight change (99.91%), sleeping disorder (83.60%) and feeling tired (81.59%), stood for the top 3. As for each episode, the proportions and the total number of depressive symptoms appeared higher among females (P < 0.05). One third of the patients did not seek for any social support or psychotherapy with only 8.99% had ever taken antidepressant drugs. CONCLUSION: Rates of depression varied significantly between social groups in Chinese adults aged 30-79. In this study, only 65.19% of the MDE patients ever has sought help or received treatment.