Alcohol and Sleep: How Does Drinking Impact Your Quality of Rest?

It’s been a long day at work and all you want is a glass of wine or a beer to relax. Your coworkers might invite you out for drinks, or your significant other might hand you a glass of your favorite alcoholic beverage to help you unwind. These scenarios happen all the time, but how are those evening drinks affecting your sleep? There is an old wives’ tale stating that a nightcap before bed will help you sleep better. Unfortunately, the opposite is true.

Alcohol is categorized as a depressant or sedative. The sedative effects of alcohol reduce neuronal firing in the prefrontal cortex, making this control center of the brain relax and help you wind down after a long day. This is also why people become more sociable when drinking at parties or gatherings; all of your concerns are temporarily quieted, but so is your ability to restrain thoughts and actions.

Over time, alcohol begins to affect other parts of the brain. The extensive list of brain regions affected includes:

• Prefrontal cortex (involved with decision-making, response inhibition, attention regulation, and memory processing)

• Limbic system (involved with emotion)

• Basal forebrain (involved with learning and memory)

• Hypothalamus (involved with hormonal regulation, mood, sex drive, hunger and thirst, blood pressure, and sleep)

• Thalamus (involved with motor movement, sensory information except for smell, learning and memory, consciousness, and the sleep/wake cycle).

  
  

Reflecting on past experiences with inebriated people may help you understand how alcohol's influence on these brain regions can lead to interesting behaviors and outcomes.

Given the impact of alcohol on various brain regions, let's delve into how its sedative effects influence your sleep. Contrary to popular belief, alcohol doesn't help you fall asleep; it makes you lose consciousness. When your body is 'knocked out' by alcohol, you become unconscious. Interestingly, alcohol consumption causes frequent awakenings throughout the night, which we don't remember due to the sedated state of our brain. It may seem like you “sleep” more soundly because your body has slipped into an immobile stupor but, in reality, you are not receiving consecutive, natural sleep.

Further, alcohol reduces the amount of rapid eye movement (REM) sleep, or dream sleep, that we get. When alcohol is metabolized, it produces ketones and aldehydes, which suppress the brain’s ability to initiate REM sleep. This effect occurs even if you drink in the afternoon.

As adults, receiving 2 hours of REM sleep is important for healthy brain function, emotional processing, and memory consolidation. Without this important stage of the sleep cycle, we can have impairments in memory and learning. What's more, most of our REM sleep is obtained in the second half of the night/early morning. Therefore, if you need to wake up early the next day, you are probably receiving less than this necessary 2 hours and will feel the effects of difficulty concentrating, forgetfulness, and daytime sleepiness the following day. 

The real kicker is that drinking at all when you need to study for a test or memorize something for work will reduce your ability to remember the content by 40-50% a week later. That’s right, half of your time and effort will be wasted. While it may seem overly cautious, abstaining from alcohol can significantly improve your performance at school or work.

On a related note, if you have been feeling anxious or depressed lately and you think this has increased your alcohol intake to more than 4 drinks/day or 10 drinks/week, please see the resources listed below for more information on alcohol and alcohol use disorder. The author reminds you to please drink responsibly. 

References

“Alcohol.” Alcohol - Alcohol and Drug Foundation, adf.org.au/drug-facts/alcohol/. Accessed 16 Dec. 2024. 

Brower, Kirk J, and Brian E Perron. “Sleep Disturbance as a Universal Risk Factor for Relapse in Addictions to Psychoactive Substances.” Medical Hypotheses, U.S. National Library of Medicine, May 2010, pmc.ncbi.nlm.nih.gov/articles/PMC2850945/.

Ciraulo, A., et al. “Outcome Predictors in Substance Use Disorders.” The Psychiatric Clinics of North America, U.S. National Library of Medicine, June 2003, pubmed.ncbi.nlm.nih.gov/12778840/.

“Home.” Sleep Foundation, 3 Mar. 2023, www.sleepfoundation.org/. 

“Hypothalamus: What It Is, Function, Conditions & Disorders.” Cleveland Clinic, 17 Sept. 2024, my.clevelandclinic.org/health/body/22566-hypothalamus. 

Oscar-Berman, M., and K. Marinkovic. “Alcoholism and the Brain: An Overview.” Alcohol Research & Health : The Journal of the National Institute on Alcohol Abuse and Alcoholism, U.S. National Library of Medicine, 2003, pmc.ncbi.nlm.nih.gov/articles/PMC6668884/#:~:text=Areas%20of%20the%20brain%20that,releases%20hormones%20in%20response%20to. 

“REM Sleep: What It Is and Why It’s Important.” Sleep Foundation, 22 Mar. 2024, www.sleepfoundation.org/stages-of-sleep/rem-sleep#:~:text=All%20sleep%20is%20important%2C%20but,processing%2C%20and%20healthy%20brain%20development. 

“Thalamus: What It Is, Function & Disorders.” Cleveland Clinic, 1 May 2024, my.clevelandclinic.org/health/body/22652-thalamus. 

Walker, Matthew P. Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner, an Imprint of Simon & Schuster, Inc, 2018.