The application of the tools of epidemiology to psychiatry have led to both methodological developments including the introduction of structured and scmistructured diagnostic interviews and statistical methods for estimating prevalence and correlates of mental disorders, and substantive findings regarding the high prevalence of mental disorders in the general population, patterns of comorbidity within and between classes of disorders, sociodemographic and environmental correlates and risk factors for mental disorders, and service patterns in general population samples.4
