The current status of tardive dystonia

Tardive dystonia (TDt), a persistent dystonia associated with exposure to neurolept ic drugs, is an uncommon disorder. It differs from tardive dyskinesia (TDk) in epidemiology, clinical features, risk factors, pathophysiology, course, prognosis, and treatment outcome. TDt seems to develop faster and is more painful, distressing, and disabling than tardive dyskinesia. In this article, evidence is reviewed on the face, descriptive, construct and predictive validity of this iatrogenic complication of antipsychotic drugs. It is suggested that TDt should not be lumped together with TDk. It deserves a separate nosological status as an independent diagnostic category. The subclassification of TDt into various subtypes based on coexistence of other movement disorders is suggested. (C) 1999 Society of Biological Psychiatry.