Pimozide Treatment in Disruptive Severely Retarded Patients

Eight severely retarded residents took part in a double blind, placebo controlled trial of pimozide. The drug did not alter behavioural adjustment as assessed by behaviour observations. However, ratings on a standardised checklist of aberrant behaviour showed significant drug-induced improvements on two dimensions (Irritability and Hyperactivity/non-compliance). Learning performance, as assessed by a discrimination learning task, was not affected by the drug.