Obsessive-compulsive disorder (OCD) is a common psychological disorder that manifests itself in repetitive actions that a person can’t help themselves from undertaking – whether washing their hands, arranging items in a certain order, checking and re-checking to see if a door is locked, or thinking unwanted or inappropriate thoughts. When a person realizes that their behavior is not normal but still can’t stop doing it, when they spend an inordinate amount of time each day engaging in repetitive behavior, or when a particular “habit” causes problems in their everyday life, medical evaluation is recommended for a possible obsessive-compulsive disorder. While OCD can occur and be diagnosed at any age, most patients are identified with it before the age of 20. A specific cause of the disorder has not yet been found, but evidence suggests that certain brain abnormalities may be involved. Treatments can include oral medications, psychotherapy and clinical trials.