Alcohol's effects on sleep in alcoholics

Abstract

Sleep problems, which can have significant clinical and economic consequences, are more common among alcoholics than among nonalcoholics. During both drinking periods and withdrawal, alcoholics commonly experience problems falling asleep and decreased total sleep time. Other measures of sleep are also disturbed. Even alcoholics who have been abstinent for short periods of time (i.e., several weeks) or extended periods of time (i.e., several years) may experience persistent sleep abnormalities. Researchers also found that alcoholics are more likely to suffer from certain sleep disorders, such as sleep apnea. Conversely, sleep problems may predispose some people to developing alcohol problems. Furthermore, sleep problems may increase the risk of relapse among abstinent alcoholics.

Figure 1

A summary of nocturnal sleep changes in alcoholic patients as determined across various polysomnographic studies of acute alcohol administration and withdrawal. The studies measured sleep characteristics at baseline, after drinking, and during acute alcohol withdrawal. Note that the size of the bars indicates only the direction, but not the magnitude, of the changes. Both after drinking and during withdrawal, sleep latency increases and total sleep time decreases, compared with the response at baseline. Both the percentage of deep sleep, or slow-wave sleep (SWS), and the rapid eye movement (REM) sleep latency increase during drinking and return to baseline levels during withdrawal. Although SWS% returns to baseline values during withdrawal, researchers should note that baseline values of SWS% in alcoholics are still lower than values from control subjects. REM% decreases with drinking and then returns to or even exceeds baseline levels during withdrawal. NOTES: Sleep latency is the time between going to bed and actually falling asleep. SWS% is the proportion of deep sleep, or SWS, during total sleep time. REM% is the proportion of REM sleep during total sleep time. REM latency is the time between sleep onset and the onset of the first episode of REM sleep.

Figure 2

A model of the reciprocal relationships between heavy alcohol consumption and sleep disturbances. Sleep disturbance may lead to increased alcohol consumption for self-medication. At the same time, alcohol consumption, through its effects on brain chemicals (i.e., neurotoxicity), may lead to sleep disturbance. Sleep disturbance is also a risk factor for developing alcohol-use disorders (i.e., alcohol abuse and alcohol dependence). Treatment of these disorders can lead to abstinence, but sleep disturbances may persist even during recent and sustained abstinence. Sleep disturbances at the time of treatment are risk factors for relapse to drinking. In turn, relapse contributes to alcohol neurotoxicity and persistent sleep disturbances. The question mark represents the untested hypothesis that treatment of sleep disturbances as an adjunct to alcoholism treatment can facilitate abstinence and decrease the risk of relapse. Purple arrows indicate processes that favor unhealthy patterns of drinking, blue arrows indicate processes that favor sleep disturbance, and yellow arrows represent treatment processes that may favor abstinence.