[Epidemiology of obsessive-compulsive disorder: a review]

Epidemiological surveys are important because clinical samples are subject of several selection biases. Sociodemographic factors and clinical aspects of the morbid condition itself influence help seeking behaviors. Due to the egodystonic nature of obsessive-compulsive disorder, sufferers tend to hide their symptoms and avoid or delay treatment seeking. However, most of our current knowledge about obsessive-compulsive disorder is based on clinical samples, which do not represent the totality of cases. A conventional Medline, PsychoInfo and Lilacs review of epidemiological studies on obsessive-compulsive disorder from 1980 to 2004 was conducted, using the following keywords: "epidemiology", "obsessive-compulsive disorder", "populational surveys" and "prevalence". Studies from different countries show an average point-prevalence of 1% and lifetime prevalence of 2-2.5% for obsessive-compulsive disorder. In contrast with clinical samples, most populational samples have a predominance of females and cases with only obsessions. The frequent comorbidity with other mental disorders, particularly depression and other anxiety disorders, has also been found in cases from the community, which have an association with substances misuse as well. Many sufferers are not been treated, particularly the "pure" cases. Indicators of functional incapacitation show a considerable negative impact of obsessive-compulsive disorder. It is necessary to increase the awareness about obsessive-compulsive disorder symptoms in the community and among health professionals, in order to increase help seeking, as well as the proper identification and treatment of this rather serious medical condition.