Orofacial dyskinesia, cognitive function and medication.

The presence of tardive dyskinesia in a sample of 43 patients with schizophrenia and 37 psychopaths who had been hospitalised for many years and exposed to large amounts of medication was assessed while testing their cognitive function. Subjects who showed no evidence of abnormal movements performed significantly better on the test of delayed recall, but there were no differences in performance on any of the other tests of cognitive function used. Multiple regression analysis revealed that age and the total lifetime dose of neuroleptic medication received (in chlorpromazine equivalents) were the only variables to predict the Abnormal Involuntary Movement Scale score, although a large amount of variance in this variable was unaccounted for. The duration of treatment with neuroleptics did not predict AIMS score.