Spoiler alert: It’s not good.  

St. Patrick’s Day is here! Celebrating Irish heritage in America often means wearing a good deal of green, listening to fiddle-filled folk music, maybe some Irish step dance for good luck. 

It also often means a good excuse to buy a lot of beer and/or carouse at your favorite pub or watering hole for most of the night – and maybe into the morning! 

For many of us that aren’t in our college years, hard drinking leads to splitting hangovers that will have us bedridden until the afternoon at least – and make us swear we’ll never drink alcohol again. But what if alcohol had deeper affects on your brain than even the hangover? 

Initial Effects of Alcohol on Sleep

Many folks say they sleep better with alcohol – that they fall asleep almost immediately. It’s true that alcohol is a depressant, a drug which promotes a sensation of relaxation and sleepiness, and may help some fall asleep faster. In non-alcohol-dependent people, alcohol has that lulling effect regardless of if the alcohol dose is high or low. But alcohol has that effect only for those who are not alcohol dependent. 

For people who are alcohol-dependent or have high alcohol tolerances, alcohol’s ability to cause someone to fall asleep decreases and instead alcohol consumption makes them stay awake longer. This is especially true for individuals who repeatedly use alcohol as a sleep aid, such as people who suffer from insomnia and frequently use alcohol as a little “push” to get their bodies to relax before sleep. 

At any rate, falling asleep faster doesn’t mean that you’re sleeping better. Because even once you fall asleep, no matter how fast, the alcohol is still at work in your bloodstream. 

Later Effects of Alcohol on Sleep

For many people, the most serious effects of alcohol on one’s sleep schedule appear later in the night and affect a person’s natural sleep cycles throughout the night.  

Humans naturally cycle through four different kinds of sleep every 90-120 minutes. The last of the four stages is REM (rapid eye movement) sleep. This is the sleep stage most responsible for dreaming and is thought to have a critical role in memory retention, learning, and creativity. During a normal night of sleep, your body would ideally go through four or five full sleep cycles to get the amount of rest needed to stay healthy. 

Alcohol in large amounts tends to impede the brain’s ability to reach REM sleep by prolonging the third stage of sleep and thus preventing the transition into REM sleep. By preventing the body from reaching the deepest stage of sleep, alcohol leads to more disruptions during the night and increased wakefulness. And what do disruptions and increased wakefulness lead to? Poor-quality sleep. And since the body doesn’t reach REM sleep as reliably, memory problems and difficulty focusing might arise – especially if alcohol is consistently consumed in large amounts over time before sleep. 

In alcohol-dependent individuals, the effects are even more pronounced. Many studies show a prominent link between alcoholism and insomnia, says Ian Colrain in his article “Alcohol and the Sleeping Brain.” Insomnia, which naturally produces irregular sleep patterns (like napping and erratic sleeping and waking schedules), also result in poor-quality sleep over a long period of time. Alcoholism could also possibly have “long-lasting neurochemical changes in the brain stem” due to altered lengths of sleep cycles in alcoholics versus non-alcoholics. 

Conclusion

While all of the above are common side effects of ingesting alcohol before sleeping, the actual effects vary widely from person to person depending on age, alcohol tolerance, weight, gender, how fast the alcohol was ingested, how soon before sleeping the alcohol was ingested, and more. 

So before you take that extra pint that lad’s offering you, think about the effects of that ale on your sleep – and how you’ll wake up tomorrow! Another good rule of thumb is to avoid alcohol 6 hours before your usual bedtime to prevent sleep and health disruptions.

Sources: 

https://www.sleepfoundation.org/nutrition/alcohol-and-sleep

https://www.webmd.com/sleep-disorders/news/20130118/alcohol-sleep

https://www.sleepfoundation.org/stages-of-sleep

https://pubs.niaaa.nih.gov/publications/arh25-2/101-109.htm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821259/