Alcohol-Induced Sleepiness and Memory Function

Abstract

Alcohol has sedative, as well as performance and memory-impairing effects. Several independent lines of research indicate that alcohol-induced sleepiness may contribute to the observed memory and performance impairment. Such a link would imply that alcohol consumption in combination with other drugs or conditions that enhance sleepiness could increase the risk for alcohol-related impairment.

Keywords: AOD impairment; AODE (alcohol and other drug effects); neurotransmitters; sedatives; sleep.

Figure 1

Sleepiness increases and sleep latency (i.e., the time [in minutes] between lying down and the onset of sleep) decreases after progressive sleep restriction. Subjects were tested with the Multiple Sleep Latency Test on days 1, 2, and 5. On the test days, subjects’ sleep latency was determined four times. The figure shows both the sleep latency at each measurement and the mean of all four measurements. ¹TIB = time in bed. SOURCE: Adapted from Zwyghuizen-Doorenbos et al. 1988.

Figure 2

Alcohol consumption reduces sleep latency (i.e., increases sleepiness) in a dose-dependent manner. Sleep latency (in minutes) was determined after the subjects received alcohol doses of 0.0, 0.4, 0.6, and 0.8 gram per kilogram of body weight. The circles represent the mean values of four tests over the course of a day. Vertical lines indicate the standard error. SOURCE: Adapted from Roth et al. 1989/1990.

Figure 3

Different sedative drugs differentially decrease sleep latency (i.e., increase sleepiness). All subjects were tested under four conditions: after receiving a placebo, after receiving alcohol (0.6 gram per kilogram of body weight), after receiving the antihistamine diphenhydramine (50 milligrams), and after receiving the benzodiazepine triazolam (0.25 milligram). For each condition, the subjects were tested over a 2-day period. On one day, they took a 1-hour nap 1 hour after drug administration; on the other day, they did not take a nap. The sleep latency for the different conditions is the mean of four measurements taken over the course of the day. Vertical lines indicate the standard error. SOURCE: Adapted from Roehrs et al. 1993.