ALERTNESS AND MEMORY AFTER SLEEP-DEPRIVATION AND DIAZEPAM INTAKE

Benzodiazepines (BZDs) give rise to memory impairments. It has been qu estioned whether or not these impairments are related to the drug's se dative, alertness-reducing effects. Therefore, in this study, alertnes s was reduced in healthy subjects both pharmacologically (15 mg diazep am) and non-pharmacologically (24-h sleep deprivation, SD) in order to assess whether these manipulations both gave rise to memory impairmen ts. Twelve subjects were tested using a repeated measures cross-over d esign. Drug administration was placebo-controlled and double-blind. A subjective alertness reduction was established after diazepam intake a nd even more after SD. Additionally, performance-disruptive effects we re found on psychomotor tasks after both SD and diazepam intake. Howev er, only diazepam, and not SD, impaired delayed recall of a word list and recall of paired associates. Thus a reduction in alertness, i.e. s edation, cannot fully account for BZD-induced memory impairments.