Obsessive-compulsive disorder in elderly patients.

Obsessive-compulsive disorder (OCD) is a common illness which starts in young adulthood and persists into late life. OCD is associated with dysregulation of the serotonin system and may also be related to the dysregulation of dopamine. When OCD starts in an elderly patient, either an organic or a neurological diagnosis should be considered. Clomipramine and serotonin reuptake inhibitors are the mainstay of treatment for OCD. Choice of a particular agent should be based on the patient's previous response and the adverse effect profile of the drug. Pharmacokinetics should also be a consideration due to age-related changes in hepatic and renal function leading to increased plasma concentrations as well as prolonged elimination half-lives of these agents. Behavioural therapy, in addition to pharmacological management, is essential to treat compulsions and to improve response.