The Effects of Alcohol on Sleep

Question

What are the effects of alcohol on sleep?

Response from Karl Doghramji, MD

Alcohol is used extensively as a sleep aid in the general population. In a recent survey,^[1] 28% of insomniacs indicated that they had used alcohol to help them fall asleep. Occasional insomniacs used alcohol for an average of 3.6 nights/month, while chronic insomniacs used alcohol for an average of 6.8 nights/month. An equal number of occasional insomniacs and chronic insomniacs (67%) described alcohol as an effective or very effective method to induce sleep.

When ingested by normal individuals, alcohol leads to a more rapid induction of sleep. It also increases non-REM sleep and reduces REM sleep during the first portion of the night. However, alcohol is metabolized rapidly and blood concentrations are negligible by the middle of the night for most individuals who have a few drinks prior to bedtime, often resulting in withdrawal symptoms thereafter. These may include shallow sleep and multiple awakenings, REM rebound associated with nightmares or vivid dreams, sweating, and general activation.^[2,3] Therefore, although alcohol may be effective in sleep induction, it impairs sleep during the second half of the night and can lead to a reduction in overall sleep time. As a result, it can also be associated with daytime somnolence. It is of interest that alcohol's negative effects on sleep are even observed when it is ingested in the late afternoon.

Insomnia is often a chronic condition, and chronic reliance on alcohol increases the risk of development of alcohol dependence and alcoholism. Alcoholism itself is also associated with the complaints of poor sleep characterized by prolonged time to fall asleep, multiple awakenings, and decreased delta and REM sleep.^[4] Sleep changes can persist during months or years of abstinence, and recent studies indicate that certain alterations in sleep architecture, as well as subjective sleep complaints, predict relapse to alcoholism.^[5] A variety of sleep disorders can be responsible for insomnia; these include sleep-related breathing disorders, such as obstructive sleep apnea syndrome. Alcohol increases the severity of the syndrome, and may cause snoring and induce apneas in individuals without a history of obstructive sleep apnea syndrome.^[6]

In conclusion, alcohol is a commonly used substance for sleep induction. However, it is a poor choice as a hypnotic because it can disrupt sleep even further, may lead to alcohol dependence and alcoholism, and may intensify sleep-related breathing disturbances.