Nine chronic schizophrenic patients being treated with high-potency
antipsychotic medication and antiparkinsonian agents were enrolled in a
double-blind, crossover trial comparing amantadine and trihexyphenidyl.
Memory function was assessed with the Rey Auditory-Verbal Learning Test
during each 6-week drug trial. The subjects performed significantly better
while receiving amantadine. Examinations of computed tomographic studies of
seven subjects revealed a significant inverse correlation between ventricle
size and memory while they were taking trihexyphenidyl but not amantadine.
This suggests that patients with underlying brain pathology may be
particularly vulnerable to the memory- disrupting effects of