Effect of diazepam and chlorpromazine on memory functions in man

The effect of a single oral dose of diazepam 10 mg or chlorpromazine 25 mg on memory in man was examined in a double-blind study, each drug being crossed-over against placebo, with 20 subjects for each drug. Kahn's Test for Symbol Arrangement and a paired association-learning task were used for assessment of acquisition, storage and retrieval, and state-dependency effects. A flicker-fusion test, two coordination tests, and a choice reaction task were used to evaluate alertness in the subjects. Diazepam significantly impaired acquisition, but slightly facilitated recall. Reaction time was shortened after acute diazepam treatment and coordination was impaired after two weeks treatment with diazepam. Acute treatment with chlorpromazine did not change memory or psychomotor performance.