Differential amnestic properties of short- and long-acting benzodiazepines.

It has been demonstrated previously that orally administered lorazepam can cause anterograde amnesia in young adults. In this study, the effects of 7.5 and 15 mg clorazepate and 1 and 2 mg lorazepam on recall were compared in 74 healthy adults. Word list presentation tests were administered to subjects at selected intervals to measure immediate and delayed recall. Statistically significant memory impairment was found with 2 mg lorazepam during both immediate and delayed recall testing. Clorazepate produced no statistically significant amnestic effects. The data suggest that benzodiazepines differ in their potential for causing memory impairment.