Obsessive-compulsive disorder (OCD) is a psychiatric disorder in which the patient suffers from recurrent intrusive ideas, impulses, thoughts (obsessions), and/or patterns of behavior (compulsions) that are ego-alien and produce anxiety if resisted. The ego-dystonic nature of OCD is one of the hallmarks of this disorder. OCD can be a disabling condition because the obsessions and compulsions are time-consuming and interfere with patients' everyday activities and their relationships with friends and family. In severe cases, OCD conflicts even with the simplest tasks of daily living.
Research interest in OCD has been growing steadily in the past decade. A search on MEDLINE reveals an over 300% increase in citations on OCD from 1986 to 1998. These range across the spectrum of research fields, from genetic studies, brain imaging, and neurobiological research examining the underlying pathogenesis of OCD to epidemiological studies evaluating the course of clinical symptoms, comorbidities, and outcomes. Each area represents an important piece in the complex jigsaw puzzle of OCD.