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Alcohol is a highly-abused substance that greatly exacerbates sleep problems. During abstinence, residual disruptions in sleep maintenance and sleep architecture are the greatest predictors of relapse [1].

Moderate alcohol consumption and sleep disruptions

Moderate alcohol consumption 30-60 minutes before bedtime catalyzes disruptions in sleep maintenance and sleep architecture that are mediated by blood alcohol levels [2]. 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 percent and decrease 0.01-0.02 percent per hour, an alcohol clearance rate of 4-5 hours would coincide with disruptions in sleep maintenance in the second half of an 8 hr sleep episode [2]. 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 hr 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 hr sleep episode [2]. Enhancements in REM sleep and SWS following moderate alcohol consumption are mediated by reductions in glutamatergic activity by adenosine in the central nervous system [2]. In addition, tolerance to changes in sleep maintenance and sleep architecture develops within 3 days of alcohol consumption before bedtime [2].

Alcohol consumption and sleep improvements

Low doses of alcohol (one 12 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) [3]. 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 [4]. In insomniacs, moderate doses of alcohol improve sleep maintenance [5].

Alcohol consumption and fatigue

Sleepiness influences the severity of alcohol consumption. Conditions of sleep deprivation encourage more episodes of alcohol consumption [2]. Increased alcohol consumption during the winter months for Northern climate residents is attributed to escalations in fatigue [6].

Alcohol abstinence and sleep disruptions

Sleep and hormonal disruptions following withdrawal from chronic alcohol consumption are the greatest predictors of relapse [1]. During abstinence, recovering alcoholics have attenuated melatonin secretion in the beginning of a sleep episode, resulting in prolonged sleep latencies [7]. Escalations in cortisol and core body temperatures during the sleep period contribute to poor sleep maintenance [7,8].

References

1. Feige, B., Scaal, S., Hornyak, M., Gann, H., Riemann, D. Sleep electroencephalographic spectral power after withdrawal from alcohol in alcohol-dependent patients. ALcoholism: Clinical and Experimental Research. 2007 Jan ; 31 (1): 19-27.
2. Roehrs, T., and Roth, T. Sleep, sleepiness, and alcohol use. Alcohol Research & Health. 2001; 25(2):101-109.
3. Stone, B. Sleep and low doses of alcohol. Electroencephalography and Clinical Neurophysiology. 1980; 48: 706-709.
4. Schuckit, M.A. Low level of response to alcohol as a predictor of future alcoholism. Am J Psychiatry. 1994 Feb;151(2):184-189.
5. Rohers, T., Papineau, B.A., Rosenthal, L., Roth, T. Ethanol as a hypnotic in insomniacs: self administration and effects on sleep and mood. Neuropsychopharmacology. 1999 Mar; 20(3):279-86.
6. Levine, M.E., Duffy, L.K., Bowyer, R.T. Fatigue, sleep, and seasonal hormone levels: implications for drinking behavior in Northern climates. Drugs & Society. 1994; 8(2): 61-70.
7. Kühlwein, E., Hauger, R.L., Irwin, M.R. Abnormal nocturnal melatonin secretion and disordered sleep in abstinent alcoholics. Biol Psychiatry. 2003; 54: 1437-1443.
8. Danel, T., Libersa, C., Touitou, Y. The effect of alcohol consumption on the circadian control of human core body temperature is time dependent. Am J Physiol Regulatory Integrative Comp Physiol. 2001; 281: R52-R55.