Epidemiology and genetics of obsessive-compulsive disorder

This article reviews the epidemiology of obsessive-compulsive disorder (OCD). The estimated prevalence of OCD in the community is 2-3%. The condition appears to be somewhat more prevalent in women; less prevalent in older subjects; and relatively infrequent in minority groups. Most cases have onset before the age of 25, and symptoms may first occur in childhood and adolescence. The majority of cases have a course marked by episodes of illness with periods of incomplete remission. Comorbid conditions, especially major depression and phobias, are common. Evidence from twin and family studies suggests that OCD may be inherited. Ongoing family studies are investigating the phenotypic spectrum that may be transmitted; the clinical and etiologic heterogeneity of the condition; the possible mode of inheritance; and the identification of genes that may be implicated. This information will be important for understanding the pathophysiology of OCD and for developing effective treatment approaches.