15 million Americans struggle with alcohol-use disorder (AUD) – dependence on alcohol!
Of those diagnosed with AUD, between 36% to 72% report difficulty falling or staying asleep (i.e., insomnia). Even more concerningly, alcohol's effect on sleep can persist for weeks to months after the last drink. As a result, many patients resort to using alcohol again, hoping it will help them sleep. This sets off a vicious cycle of alcohol use, relapse, and insomnia, incurring societal costs exceeding $18 billion in the US.
In this article, the experts at Confidant Health break down the effects of alcohol on sleep and ways to deal with it.
What Is Alcohol Withdrawal Insomnia?
Alcohol withdrawal insomnia refers to the sleeping difficulties (trouble falling or staying asleep) in patients with AUD who quit alcohol. To understand the reasons for this, let’s discuss alcohol’s effects on sleep.
The Effects of Alcohol on Sleep
- Non-rapid eye movement (NREM) sleep dominates the first half of the night and is characterized by slowed breathing and heart rate and a lower body temperature.
- Rapid eye movement (REM) sleep usually governs the second half of the night, with heightened brain activity and loss of muscle tone as its main features.
Next, we’ll discuss how alcohol affects each phase differently:
Effects of Alcohol on NREM Sleep
Studies show that alcohol intake reduces the time it takes to fall asleep (which is why alcohol is often used as a sleeping aid) while increasing NREM duration. This is because alcohol triggers the release of Gamma-aminobutyric acid (GABA), a chemical that suppresses brain activity.
Effects of Alcohol on REM Sleep
As it is an inhibitory neurotransmitter, releasing GABA suppresses the REM sleep cycle (which is characterized by an excitatory brain state). The brain compensates for this by increasing sensitivity to glutamine (an excitatory neurotransmitter).
Thus, as the body metabolizes and excretes alcohol (usually by the second half of the night), an exaggerated response to glutamine (without the GABA release to counterbalance it) leads to waking up more often.
Why Does Alcohol Withdrawal Cause Insomnia?
Long-term alcohol use depletes GABA reserves and increases glutamine sensitivity. This results in difficulty falling asleep and staying asleep due to the predominantly excited brain state experienced by users who quit alcohol.