An assessment of tardive dyskinesia in schizophrenic outpatients.

An examination of tardive dyskinesia in 213 schizophrenic outpatients using the Abnormal Involuntary Movement Scale (AIMS) indicates that increasing age is significantly associated with the presence of this disorder while sex is not. Both sexes showed significant linear increases with increasing age. Although males did not evidence the statistically significant curvilinear trend previously reported in an inpatient study using the same methodology, they displayed an attenuated effect at the older age levels. A comparison of prevalence values between the outpatient sample and the inpatient sample previously studied indicated no greater prevalence in the outpatients. However, an examination of differences in AIMS total scores between these samples suggested the presence of many more marginal and mild movements in the outpatients. Reasons for the differences between the inpatient and outpatient studies are discussed.