No abstract

LTHOUGH COMMUNITY SURveys of mental disorders have been conducted in the United States since the end of World War II, 1-3 it was not until the early 1980s that fully structured lay interviews were developed to diagnose specific mental disorders. The first such instrument was the Diagnostic Interview Schedule (DIS), 4 which was developed for use in the Epidemiologic Catchment Area (ECA) study 5 to estimate the general population prevalence of mental disorders by Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III) criteria. 6 Major depressive disorder (MDD) prevalence estimates in the ECA sites were 3.0% to 5.9% for lifetime and 1.7% to 3.4% for 12-month. 7 The first nationally representative survey using a method similar to the ECA, the National Comorbidity Survey (NCS), 8 was conducted a decade later in 1990-1992. The NCS diagnostic instrument was a modified version of the Composite International Diagnostic Interview (CIDI) 9 to assess mental disorders by Author Affiliations are listed at the end of this article.

Background-Mental disorders are leading causes of disability worldwide, including in lowand middle-income countries least able to bear such burdens. To begin understanding and improving their treatment, we describe mental health care in 17 countries of the WHO World Mental Health (WMH) Survey Initiative.

Aims-The paper reviews recent findings from the WHO World Mental Health (WMH) surveys on the global burden of mental disorders.Methods-The WMH surveys are representative community surveys in 28 countries throughout the world aimed at providing information to mental health policy makers about the prevalence, distribution, burden, and unmet need for treatment of common mental disorders.Results-The first 17 WMH surveys show that mental disorders are commonly occurring in all participating countries. The inter-quartile range (IQR: 25 th -75 th percentiles) of lifetime DSM-IV disorder prevalence estimates (combining anxiety, mood, externalizing, and substance use disorders) is 18.1-36.1%. The IQR of 12-month prevalence estimates is 9.8-19.1%. Prevalence estimates of 12-month Serious Mental Illness (SMI) are 4-6.8% in half the countries, 2.3-3.6% in one-fourth, and 0.8-1.9% in one-fourth. Many mental disorders begin in childhood-adolescence and have significant adverse effects on subsequent role transitions in the WMH data. Adult mental disorders are found to be associated with such high role impairment in the WMH data that available clinical interventions could have positive cost-effectiveness ratios.Conclusions-Mental disorders are commonly occurring and often seriously impairing in many countries throughout the world. Expansion of treatment could be cost-effective both from both employer and societal perspectives.As health care spending continues to rise (World Health Organization, 2006), resource allocation decisions will need to be based increasingly on information about prevalence and severity of disorders and cost-effectiveness of interventions. This will require disorderspecific information to be obtained not only about prevalence, but also about disability (Katschnig et al. 1997;Murray & Lopez, 1996). Despite the fact that many studies in developed countries have estimated the effects of specific disorders on disability (Berto et al. 2000;Maetzel & Li, 2002;Reed et al. 2004), comparative studies are rare (Druss et al. 2008;Merikangas et al. 2007). Recognizing the importance of this information, one of the main aims of the WHO World Mental Health (WMH) Surveys is to produce data on the prevalence and severity of mental disorders in each participating WMH country. Although this is still a work in progress, enough useful information has been produced on overall prevalence and severity of mental disorders in the WMH surveys to warrant a review of this evidence. The use of a fully-structured interview was critical to the success of the WMH, as many participating countries do not have the critical mass of trained mental health professions needed to implement a large-scale clinical survey. However, the WMH collaborators are encouraged to carry out blinded clinician re-interviews with a probability sub-sample of WMH respondents in order to confirm that the diagnoses generated by the CIDI are consisted with independent clinical diagnoses generated by culturally competent clinicians. Methodological studies of...