Alcohol is a depressant that slows down the central nervous system, acting as a sedative. This can sometimes make it easier to fall asleep initially. However, as the brain recognizes a depressant in the physical system, it releases wakeful stimulants such as adrenaline.
You might have noticed that you typically wake up at around 2 or 3 a.m. on days you drink. This is because as the sedative effects of alcohol begin to fade, the adrenaline takes control and wakes you up!
This process makes us much more prone to sleep disruptions during the night, shortening our overall sleep duration. It also causes issues with our circadian rhythm since as soon as we add alcohol into the mix, our bodies no longer naturally control when we feel awake and when we feel sleepy.
As mentioned, consuming alcohol before bed leads to frequent disruptions during the night due to adrenaline. These interruptions then cause an imbalance in the amount of time we spend in our different sleep phases. Alcohol specifically tends to interfere with our REM sleep, so we end up devoting disproportionate time to non-REM sleep. We no longer spend nearly enough time in the REM stage of our sleep cycle.
Though it may seem harmless, losing out on REM sleep significantly impacts our overall sleep quality. As mentioned earlier, the REM sleep stage is a critical period for restoration, emotional processing, and memory consolidation. If you feel like you can’t recall everything that happened prior to a night of drinking, it’s because alcohol interferes with this important sleep stage.
