Definition: Obsessive-Compulsive Disorder is a disorder characterized by the presence of obsessions and compulsions. Obsessions are repetitive, unwanted thoughts. There is a sense of urgency and tension that rises until the person feels compelled to act on the obsessive thought. An action based on an obsessive thought is called a compulsion. Compulsions range from mild checking behavior (is the stove off?) to severe cases where the person is unable to function based on their compulsions having taken over their life.

