Cross-national comparisons of the prevalences and correlates of mental disorders

The International Consortium in Psychiatric Epidemiology (ICPE) was establi shed in 1998 by WHO to carry out cross-national comparative studies of the prevalences and correlates of mental disorders. This article describes the findings of ICPE surveys in seven countries in North America (Canada and US A), Latin America (Brazil and Mexico), and Europe (Germany, Netherlands, an d Turkey), using a version of the WHO Composite International Diagnostic In terview (CIDI) to generate diagnoses. The results are reported using DSM-II I-R and DSM-IV criteria without diagnostic hierarchy rules for mental disor ders and with hierarchy rules for substance-use disorders. Prevalence estimates varied widely - from >40% lifetime prevalence of any m ental disorder in Netherlands and the USA to levels of 12% in Turkey and 20 % in Mexico. Comparisons of lifetime versus recent prevalence estimates sho w that menta I disorders were often ch ron ic, although chronicity was cons istently higher for anxiety disorders than for mood or substance-use disord ers. Retrospective reports suggest that mental disorders typically had earl y ages of onset, with estimated medians of 15 years for anxiety disorders, 26 years for mood disorders, and 21 years for substance-use disorders. All three classes of disorder were positively related to a number of socioecono mic measures of disadvantage (such as low income and education, unemployed, unmarried). Analysis of retrospective age-of-onset reports suggest that li fetime prevalences had increased in recent cohorts, but the increase was le ss for anxiety disorders than for mood or substance-use disorders. Delays i n seeking professional treatment were widespread, especially among early-on set cases, and only a minority of people with prevailing disorders received any treatment. Mental disorders are among the most burdensome of all classes of disease be cause of their high prevalence and chronicity, early age of onset, and resu lting serious impairment. There is a need for demonstration projects of ear ly outreach and intervention programmes for people with early-onset mental disorders, as well as quality assurance programmes to look into the widespr ead problem of inadequate treatment.