Review of incidence studies of tardive dyskinesia associated with typical antipsychotics.

Unless researchers make an organized effort, patients with tardive dyskinesia are difficult to study and easily lost to follow up. Because there is no treatment for tardive dyskinesia, investigators are obliged to study the natural history of the disorder and identify risk and prognostic factors to further understand pathophysiologic mechanisms and to guide prevention and treatment efforts. Abundant variability exists among incidence studies of tardive dyskinesia, depending to some extent on design issues. In this article, the design concepts of incidence and prevalence studies are described, along with results, methodological problems, and identified risk factors in various tardive dyskinesia incidence studies involving the use of typical antipsychotic medications.