[Obsessive-compulsive disorder--clinical picture, diagnosis, and therapy]

This article reviews the present state of knowledge concerning obsessive-compulsive disorder (OCD) with respect to its classification, epidemiology, pathogenesis, and therapy. Epidemiological evidence has indicated that OCD may be one of the most prevalent and disabling psychiatric disorders. There is also a high comorbidity with depression and anxiety disorders. OCD is characterized by repetitive, intrusive thoughts and images, and/or by repetitive, ritualistic physical or mental acts performed to reduce the attended anxiety. OCD is relatively common, affecting 1-3% of both adult and paediatric samples. OCD is clinically a heterogeneous condition in that two different patients with clear OCD can display completely distinct symptom patterns. Furthermore, neurobiological and psychological models concerning OCD as well as the present state of therapy are presented in detail.