[Epidemiology of obsessive-compulsive disorder].

In the article the problems of prevalence of obsessive-compulsive disorder (OCD), comorbidity with other mental disorders and the most commonly used diagnostic instruments were presented. Epidemiological data indicate OCD as the fourth most common mental disorder, which appears as frequent as asthma or diabetes. In an international study from 1994 the year's prevalence of OCD was from 1.