The paper reviews recent findings from the WHO World Mental Health (WMH) surveys on the global burden of mental disorders.

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.

The first 17 WMH surveys show that mental disorders are commonly occurring in all participating countries. The inter-quartile range (IQR: 25th-75th 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.

Mental disorders are commonly occurring and often seriously impairing in many countries throughout the world. Expansion of treatment could be cost-effective from both employer and societal perspectives