Effect of Phenothiazines on the Thinking of Acute Schizophrenics

Thirty-seven acute schizophrenic patients were given a test measuring the extent to which associatively linked distractors intruded themselves inappropriately into the generation of concepts. This test was given both upon admission to the hospital and after 6 wk. of treatment with Chlorpromazine, Fluphenazine, Thioridazine or placebo. Fluphenazine and Thioridazine produced a decrement in distractor-produced errors greater than that resulting from placebo. Changes produced by Chlorpromazine did not differ significantly from those of the placebo condition. There was a trend for Fluphenazine to be somewhat more effective than was Chlorpromazine. It was pointed out that, while both Fluphenazine and Thioridazine differ in chemical structure from Chlorpromazine, they differ markedly from each other. Some factors possibly accounting for the effectiveness of Fluphenazine were discussed, but such explanations could not be reconciled with the effectiveness of Thioridazine.