Obsessive-Compulsive Disorder
Obsessions are persistent, unwanted thoughts, impulses, or images that the person perceives as meaningless and intrusive, yet which continue to remain in their mind despite attempts to suppress or neutralize them through certain actions.
Obsessions increase anxiety. The most common obsessions include thoughts of violence (e.g., harming one’s father), contamination (e.g., contracting a serious illness by touching door handles), and doubt (e.g., persistent fear that one may have left the door open).
Compulsions are repetitive, intentional actions that reduce anxiety and are performed in order to neutralize an obsession, usually according to strict rules or in a stereotyped manner.
People feel compelled to perform these actions in order to prevent feared situations. Nevertheless, they may try to resist carrying them out because they recognize that they are unreasonable.
Compulsive actions do not provide pleasure; rather, they temporarily relieve tension and anxiety. When a person attempts to resist a compulsion, tension increases and may be relieved once the compulsive act is performed.
The most common compulsions include handwashing, counting, checking (e.g., making sure that the electric stove has been turned off), and touching (e.g., touching objects in the room before going to bed).
References:
Kaplan & Sadock: Synopsis of Psychiatry, twelfth edition
Kaplan & Sadock: Pocket Handbook of Clinical Psychiatry, fifth edition;
American Psychiatric Association: Diagnostic Manual of Mental Disorders, 1994;
Robert J. Waldinger: Psychiatry for Medical Students, third edition, translated by Anastas Suli.