Tardive dyskinesia and the long-term patient.

A psychiatric patient's long-term use of antipsychotic medication often results in the irreversible movement disorder, tardive dyskinesia. The author uses a composite case history as a basis for discussing the symptoms, diagnosis, epidemiology, and treatment of tardive dyskinesia. A number of drugs have been used to treat the disorder, but so far none have been effective. While tardive dyskinesia cannot be cured at this time, the author believes that it can be prevented by treating psychoses with the lowest possible dose of the least toxic drug for the shortest length of time.