TARDIVE-DYSKINESIA

Neuroleptic-induced tardive dyskinesia (TD) continues to be a serious problem in the psychopharmacology of schizophrenia. The overall mean p revalence of TD among chronically neuroleptic-treated patients is appr oximately 24 percent. The annual incidence in younger adults is 4 to 5 percent. Aging is a major risk factor for TD. Our ongoing prospective study suggests that the annual incidence in patients over age 45 is o ver 30 percent. Other likely risk factors include female gender, mood disorders, ''organic'' brain dysfunction or damage, diabetes mellitus, and early extrapyramidal side effects. Metoclopramide, a D2-receptor blocker commonly used in non-psychiatric medical patients, can also pr oduce persistent TD. TD can best be assessed for research purposes by a combination of subjective and objective methods. In recent years, se veral instrumental procedures have been developed to objectively quant ify various abnormal movements. The advantages and limitations of the traditional rating scales and the newer instrumental approaches are di scussed. The course of TD is variable but often not progressive. The e arly theory that striatal dopamine receptor supersensitivity causes TD has now given way to the hypothesis of multiple neurotransmitter syst em involvement. Several animal studies have reported striatal neuronal damage with prolonged neuroleptic treatment, although its relevance t o TD remains unclear. Treatments for TD, other than neuroleptic withdr awal, are still experimental.