Historical perspective on movement disorders.

Before atypical antipsychotics were developed, neuroleptics given to patients for the treatment of psychosis often caused movement disorders. Although the role of neuroleptics in the development of tardive dyskinesia was never certain, this adverse effect was of great concern to physicians because its effects could be irreversible and devastating to the patient. It is important to understand whether involuntary movement disorders are an intrinsic part of schizophrenia, because if so, then a certain percentage of patients will develop the dyskinetic syndromes whether they are treated or not. To uncover the role of antipsychotic medications in tardive dyskinesia, it is necessary to examine the descriptions of abnormal movements made by those who were first researching schizophrenia, as well as modern descriptions of neuroleptic-naïve individuals with schizophrenia. The physicians who initially described the syndrome of tardive dyskinesia had observed pre-neuroleptic schizophrenia first hand and saw a difference in the movements of treated and untreated patients. Nevertheless, the idea of a chronic movement disorder caused by treatment with neuroleptics would become controversial for many years. With the development of the atypical antipsychotics, the incidence and prevalence of tardive dyskinesia have dropped remarkably, suggesting that psychosis, its treatment, and dyskinesias are not inextricably linked.