The prevalence of presumed tardive dyskinesia in psychiatric inpatients and outpatients.

Randomly selected psychiatric patients (271 total) were examined by raters blind to diagnosis and treatment history for the presence of abnormal movements. The prevalence of presumed tardive dyskinesia among neuroleptic-exposed patients was 4.6%. If minimal rating scale criteria were applied, 9% of those patients with no history of neuroleptic exposure might have been given 'presumptive' diagnoses of dyskinesia. Problems in establishing diagnostic criteria are discussed and a longitudinal approach toward validating diagnoses is recommended.