Sedative effects of ethanol at night

The sedative effect of 0.7 g/kg of 100% ethanol, ingested at 9:30 PM, was investigated to examine the combined effects of ethanol and circadian sleepiness/alertness levels. Fourteen healthy young adults participated in a placebo-controlled, double-blind crossover design. Each subject, on two separate occasions (placebo or ethanol), completed multiple sleep latency testing and the repeated test of sustained wakefulness as objective measures of physiological sleep tendency, and completed the Stanford Sleepiness Scale as a measure of subjective sleepiness. The results indicate that a moderate dose of ethanol significantly increases physiological sleepiness during early morning hours even in individuals that are relatively alert at these times. Therefore, the marked reduction in alertness and related performance deficits that normally occur at night are worsened by ethanol ingestion. Sleepiness, due to any cause, and ethanol may well be a dangerous combination.