Tardive dyskinesia in the elderly.

Four hundred and twenty-six elderly subjects were assessed for the presence of dyskinetic movements. Dyskinetic movements were present in 49 subjects (11.5%). Ninety-two per cent had orofacial movements, by far the commonest being chewing. Dyskinetic movements were present in 12.5% of women and 7.6% of men. Abnormal movements were present in 8% of the subjects who had never received neuroleptic drugs and in 20.8% of those who had. There was a statistically significant association between developing dyskinetic movements and receiving chlorpromazine and flupenthixol. There was no association between either advancing age or dementia and dyskinetic movements.