Background: Mental disorders are major causes of disability worldwide, including in the low-income and middle-income countries least able to bear such burdens. We describe mental health care in 17 countries participating in the WHO world mental health (WMH) survey initiative and examine unmet needs for treatment. Methods: Face-to-face household surveys were undertaken with 84 850 community adult respondents in low-income or middle-income (Colombia, Lebanon, Mexico, Nigeria, China, South Africa, Ukraine) and high-income countries (Belgium, France, Germany, Israel, Italy, Japan, Netherlands, New Zealand, Spain, USA). Prevalence and severity of mental disorders over 12 months, and mental health service use, were assessed with the WMH composite international diagnostic interview. Logistic regression analysis was used to study sociodemographic predictors of receiving any 12-month services. Findings: The number of respondents using any 12-month mental health services (57 [2%; Nigeria] to 1477 [18%; USA]) was generally lower in developing than in developed countries, and the proportion receiving services tended to correspond to countries' percentages of gross domestic product spent on health care. Although seriousness of disorder was related to service use, only five (11%; China) to 46 (61%; Belgium) of patients with severe disorders received any care in the previous year. General medical sectors were the largest sources of mental health services. For respondents initiating treatments, 152 (70%; Germany) to 129 (95%; Italy) received any follow-up care, and one (10%; Nigeria) to 113 (42%; France) received treatments meeting minimum standards for adequacy. Patients who were male, married, less-educated, and at the extremes of age or income were treated less. Interpretation: Unmet needs for mental health treatment are pervasive and especially concerning in less-developed countries. Alleviation of these unmet needs will require expansion and optimum allocation of treatment resources. © 2007 Elsevier Ltd. All rights reserved.
