Neuroleptic-induced parkinsonian side effects in the mentally handicapped.

Sixty-seven neuroleptic-mediated mentally handicapped subjects in a hospital were studied to determine the prevalence of Parkinsonian side effects. A Parkinsonism scale was devised and administered. Sixty-one per cent of the sample had mild to moderately severe side effects. Sex, age, cumulative and current chlorpromazine doses, cumulative and current anticholinergic doses and anti-epileptic medication status did not predict the Parkinsonism scores. Overt brain damage was not a predictor. The difference between the neuroleptic medicated group and neuroleptic free matched controls was highly significant indicating that the Parkinsonian type of movement disorder was related to neuroleptic medication.