The present status of tardive dyskinesia and akathisia in the treatment of schizophrenia.

Motor disturbance is a major disadvantage of the antipsychotic drugs currently available for the treatment of schizophrenia. Acute akathisia is a dose-related side-effect comprising a subjective awareness of inner tension and characteristic patterns of restless movement. The natural history of akathisia is unclear, and several variants of the condition are seen in older patients on maintenance antipsychotic medication. These include acute akathisia that has persisted, and tardive akathisia which tends to be associated with signs of tardive dyskinesia. Tardive akathisia and tardive dyskinesia share some pharmacological characteristics which raises the possibility that common elements of pathophysiology underlie the 2 conditions. Tardive dyskinesia, comprising oro-facial dyskinesia and choreiform trunk and limb movements, has come to symbolize the complications of long-term antipsychotic drug treatment, although the condition is often little more than a mild social handicap and is manifest in only a minority of patients receiving such treatment. This paper discusses the treatment and patient variables that may be considered as risk factors for tardive dyskinesia. Some of the inconsistencies in the relevant literature may be explained by a speculative sub-classification of tardive dyskinesia into early and late forms. The interaction of advancing age, drug treatment and the schizophrenic disease process in the development of late dyskinesia is discussed.