Alcohol, Chemistry and You
Ethanol and Sleep
Dr. Bill Boggan

Sleep is a necessary activity for all people. Lack of sleep can lead to severe disorders including increased risk for mood disorders, impaired breathing, and heart disease. Since the average adult appears to need about 7.5 to 8 hours of sleep per night it is important that people be aware that ethanol can induce sleep problems and sleep disorders.

Normal sleep is characterized as having four (4) different stages plus an additional type of sleep called REM or rapid eye movement sleep. The four stages are generally characterized by having different types of electrical activity as measured by an electroencephalogram (EEG). Stages 1 and 2 have more rapid electrical activity, yet still slower than that seen during waking. Slow wave sleep (SWS) is most characteristic of stages 3 and 4 which are the stages of deep sleep. REM sleep, however, is characterized by having more rapid brain waves somewhat similar to those seen while one is awake. Dreaming occurs during REM, so it is interesting that the brain wave pattern during REM looks somewhat like that during wakefulness.

After first going to sleep, one progresses from stage one to stage four sleep. During the night one cycles though the different stages from one to four and return to one. REM sleep occurs during most of the cycles. As the night progresses, the deeper sleep stages become less frequent, but REM sleep tends to increase in frequency. Interestingly, studies have shown that obtaining REM sleep is important since deprivation of REM will lead to an increased amount of REM during later sleeping opportunities.

The effect of ethanol on sleep can take several forms. These include:

1. Altering the time to fall asleep

2. Disrupting the sequence of sleep

3. Altering the total time of sleep

4. Diminishing the duration of particular types or stages of sleep.

Though it is true that drinking before bedtime may cause one to fall asleep sooner, it disrupts the second half of sleep. The person may have fitful sleep by awakening from dreams and having trouble returning to sleep. This sleep disruption may manifest the next day in fatigue and sleepiness. Persons who drink too much or elderly people and women who achieve higher blood alcohol concentrations my have increased problems. It is interesting that even if ethanol is drunk earlier in the day and has cleared the system, it still has the potential to disrupt sleep later in the night. This would suggest that ethanol acts on brain systems, which are still disrupted at a later, time.

Neurotransmitters (NTs) serotonin and norepinephrine are important in the regulation of sleep. Serotonin seems primarily associated with sleep onset and with regulation of SWS, while norepinephrine seems to regulate REM and arousal. Since it known that ethanol affects both serotonin and norepinephrine, possible mechanisms for the effects of ethanol on sleep are via ethanol’s action on these NTs. 

©2003 Kennesaw State University
Principal Investigator Laurence Peterson
Project Director Matthew Hermes