Assessment of tardive dyskinesia in psychiatric outpatients using a standardized rating scale.

Psychiatric outpatients were assessed for dyskinetic movements using the abnormal involuntary movement scale (AIMS). The prevalence of tardive dyskinesia in an Australian sample of 66 patients was 44% which is similar to reported prevalence in other countries. Although the prevalence was significantly higher in patients over 45 years of age and with more than a 5 year history of neuroleptic medication, there were no significant correlations between presence of dyskinesias and age, sex or duration of neuroleptic treatment. Organic factors such as neurological disorders, ECT or alcoholism were not related to dyskinetic movements, nor was the use of anticholinergic or tricyclic antidepressant medication. The AIMS is a reliable rating scale for dyskinetic movements and could be used more widely as a screening instrument for early detection of tardive dyskinesia.