Tardive dyskinesia (TD), literally meaning a late occurring, abnormal movement disorder, was first described by Schonecker in 1957, about five years after the discovery of chlorpromazine (cited in Kane, 1992). TD generally occurs after long-term antipsychotic therapy: Kane et al (1984) reported that the incidence was increased with each subsequent year of exposure to antipsychotics, starting with an incidence of 5% after one year of exposure and increasing by 5% each subsequent year. Certainly, the prevalence of TD has increased over the last 20 years, probably as the result of more patients being exposed to antipsychotics for longer periods.