Evaluations were completed for 162 patients from Central State Hospital in Petersburg, Va. The sample consisted of chronically ill, treatment-resistant adult patients, most of whom had psychotic disorders (70%) or bipolar disorder (9%) based on DSM-IV criteria. The majority (94%) of patients were taking antipsychotic medication. Of this subset, 25% were taking a typical antipsychotic but not an atypical antipsychotic, 52% were taking an atypical antipsychotic but not a typical antipsychotic, and 23% were taking both. Each patient was rated with the Involuntary Movement Scale (2). The primary rater (D.E.R.) was trained by the developers of this scale and achieved a high level of reliability with respect to gold standard ratings (intraclass correlation coefficient [ICC]=0.96 for parkinsonism global rating, p<0.001; ICC=0.79 for dyskinesia global rating, p<0.001). A diagnosis of parkinsonism was defined as having a rating of 2 (mild) or higher on the global rating scale. Tardive dyskinesia was diagnosed by the criteria of Schooler and Kane (3).