Ethanol use and sleep

Ethanol, the type of alcohol found in alcoholic beverages, can exacerbate sleep disturbances. During abstinence, sleep disruption is one of the greatest predictors of relapse.

Moderate alcohol consumption 30–60 minutes before bedtime results in disruptions in sleep maintenance and sleep architecture that are mediated by blood alcohol levels. Disruptions in sleep maintenance are most marked once alcohol has been completely metabolized from the body. Under conditions of moderate alcohol consumption where blood alcohol levels average 0.06–0.08% and decrease 0.01–0.02% per hour, an alcohol clearance rate of 4–5 hours would coincide with disruptions in sleep maintenance in the second half of an 8-hour sleep episode. In terms of sleep architecture, moderate doses of alcohol facilitate "rebounds" in rapid eye movement (REM) and stage 1 sleep; following suppression in REM and stage 1 sleep in the first half of an 8-hour sleep episode, REM and stage 1 sleep increase well beyond baseline in the second half. Moderate doses of alcohol also increase slow wave sleep (SWS) in the first half of an 8-hour sleep episode. Enhancements in REM sleep and SWS following moderate alcohol consumption are mediated by reductions in glutamatergic activity by adenosine in the central nervous system. In addition, tolerance to changes in sleep maintenance and sleep architecture develops within 3 days of alcohol consumption before bedtime.

Low doses of alcohol (one 360.0 ml (13 imp fl oz; 12 US fl oz) beer) are sleep-promoting by increasing total sleep time and reducing awakenings during the night. The sleep-promoting benefits of alcohol dissipate at moderate and higher doses of alcohol (two 12 oz. beers and three 12 oz. beers, respectively). Previous experience with alcohol also determines whether or not alcohol is a "sleep promoter" or "sleep disrupter." Under free-choice conditions, in which subjects chose between drinking alcohol or water, inexperienced drinkers were sedated while experienced drinkers were stimulated following alcohol consumption. In insomniacs, moderate doses of alcohol improve sleep maintenance.

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