Spontaneous and tardive dyskinesias: clinical and laboratory studies.

Although rates of both tardive and spontaneous dyskinesia have increased by approximately 1% per year over the past 2 decades, the corrected tardive dyskinesia rate (with spontaneous dyskinesia subtracted) has remained fairly stable at 15% in comparisons of similar patient populations. In assessing rates of tardive dyskinesia, it is necessary to consider the influence of factors such as aging and the natural history of psychosis. Data are reviewed from clinical and animal studies that have addressed these and related factors in tardive dyskinesia. It is suggested that the competing needs to control psychosis and to manage tardive dyskinesia can be developed into a successful strategy for extended neuroleptic treatment.