Have you ever woken up not only with a pounding headache but also with a black hole in your mind, where your memories of last night seem to have gotten sucked in, never to be seen again? If you have, don’t worry – you’re not alone in that experience. More than half of college students report having experienced at least one alcohol-induced blackout. But what actually happens during a blackout? A simplified explanation might be that while you had been living your life – dancing, partying, singing – your brain hadn’t pressed “record”.
Have you ever woken up not only with a pounding headache but also with a black hole in your mind, where your memories of last night seem to have gotten sucked in, never to be seen again? If you have, don’t worry – you’re not alone in that experience. More than half of college students report having experienced at least one alcohol-induced blackout. But what actually happens during a blackout? A simplified explanation might be that while you had been living your life – dancing, partying, singing – your brain hadn’t pressed “record”.
Of course, it isn’t that simple: our memory isn’t just a recorder. Research has shown something spooky: at very high blood-alcohol concentration (BAC) levels of 0.16% or more, people can remember things that just happened – what they said a minute ago, who they were talking to – but later on, they have no memory of it at all (Felton, 2025). In other words, while alcohol leaves your short-term memory intact, your long-term memory is affected, which shows that alcohol-induced blackouts stem from a disruption in the consolidation of memories from short-term to long-term memory. You might remember that you drunkenly made out with your ex in the club when you talk to your friends about it immediately afterward, but you will have forgotten about it in the morning. While in some cases forgetting might be a good thing, it can also be scary, especially if you do not have friends that were with you the entire time to fill you in on the blanks. When you miss memories, you essentially miss a part of your life. Who knows what could have happened? Maybe you went skinny dipping in an Amsterdam canal or ended up sharing your deepest secrets with strangers.
The neurobiology behind a blackout is based on a few critical parts. Alcohol is a depressant, meaning that it slows down your brain activity by increasing the inhibitory neurotransmitter GABA. This increase in GABA activity leads to an inhibition of the brain’s communication systems (Perlmutter, 2024). The activity in the hippocampus, the brain area responsible for consolidating memories, is especially inhibited. Depending on how strongly your hippocampus is affected, you might lose just a part of your night or entire chunks.
“When you miss memories, you essentially miss a part of your life.”
In a fragmentary blackout, you might remember parts of the night: your head in a toilet while someone holds up your hair, or worse, not making it to the toilet and having everyone stare at you. Complete blackouts are called en bloc blackouts, where entire chunks of your day are gone (Wetherill & Fromme, 2016). But why does one person have a blackout after one beer while others take shots the entire night without one?
Different factors influence the possibility of having a blackout. For one, drinking a lot of alcohol in a short period of time increases your BAC quickly. If you want to keep your memories, say no to drinking games or be lame and play water pong instead. Other influential factors are lower body weight, drinking on an empty stomach, and combining alcohol with smoking weed (Richards, 2023). Additionally, the higher your tolerance, which is the amount of alcohol needed to feel its effect, the more likely you are to have a blackout. This is because a higher tolerance often makes people consume larger amounts of alcohol, which in turn increases the risk of reaching the blackout BAC level of higher than 0.16% (Richards, 2023).
“While having one blackout might feel like a funny story later on, making them a habit can cause serious damage to your brain.”
While having one blackout might feel like a funny story later on, making them a habit can cause serious damage to your brain. There are long-term effects of frequent and heavy alcohol use, as regular disruption of hippocampal activity leads to impaired cognitive function and memory over time (Nall, 2025). In fact, chronic drinking is a risk factor for a type of dementia called Wernicke-Kosakoff syndrome (WKS), which is due to the interference of alcohol with the absorption of vitamin B1 (Nall, 2025). After having had a few blackouts, your contextual memory shows impaired activity more strongly the next time you drink compared to that of a person without a history of blackouts (Wetherill, 2012).
All in all, it is your decision what matters more: a fun night out or your memory. Just know that you can have a both, as long as you pay attention to eating before drinking, pacing your drinks, and not smoking weed after alcohol (yes, even if you’re an Amsterdammer). And if you end up waking up with a black hole in your mind, make sure to consult your friends and find out if you did end up skinny dipping or making out with your ex. Would be good to know.
References
– Felton, J. (2025). What is actually happening when you get blackout drunk? an ethically dubious experiment found out. IFLScience. https://www.iflscience.com/what-is-actually-happening-when-you-get-blackout-drunk-an-ethically-dubious-experiment-found-out-80782
– Goodwin, D. W., Powell, B., Bremer, D., Hoine, H., & Stern, J. (1969). Alcohol and recall: state-dependent effects in man. Science (New York, N.Y.), 163(3873), 1358–1360. https://doi.org/10.1126/science.163.3873.1358
– Nickel, J. (2024). The biology of a blackout. Addiction Policy Forum. https://www.addictionpolicy.org/post/the-biology-of-a-blackout#:~:text=Alcohol%20is%20a%20central%20nervous%20system%20depressant
%2C%20meaning,a%20person%20is%20unable%20to%20form%20new%20memories.
– Nall, R. (2025). How alcohol is linked to memory loss. Healthline. https://www.healthline.com/health/alcoholism/alcohol-and-memory-loss
– Perlmutter, A. (2024). Want to protect your brain? Here’s what you need to know about alcohol consumption. Psychology Today. https://www.psychologytoday.com/us/blog/the-modern-brain/202403/alcohol-and-your-brain-the-latest-scientific-insights?msockid=1367f9992c006c5f3b1ded252db86d70
– Richards, V. L., Turrisi, R. J., Glenn, S. D., Waldron, K. A., Rodriguez, G. C., Mallett, K. A., & Russell, M. A. (2023). Alcohol-induced blackouts among college student drinkers: A multilevel analysis. Addictive Behaviors, 143, 107706. https://doi.org/10.1016/j.addbeh.2023.107706
– Wetherill, R. R., & Fromme, K. (2016). Alcohol-induced blackouts: A review of recent clinical research with practical implications and recommendations for future studies. Alcoholism, clinical and experimental research, 40(5), 922–935. https://doi.org/10.1111/acer.13051
– Wetherill, R. R., Schnyer, D. M., & Fromme, K. (2012). Acute alcohol effects on contextual memory BOLD response: Differences based on fragmentary blackout history. Alcoholism Clinical and Experimental Research, 36(6), 1108–1115. https://doi.org/10.1111/j.1530-0277.2011.01702.x
– White, A. M., Jamieson-Drake, D. W., & Swartzwelder, H. S. (2002). Prevalence and correlates of alcohol-induced blackouts among college students: results of an e-mail survey. Journal of American college health : J of ACH, 51(3), 117–131. https://doi.org/10.1080/07448480209596339
Of course, it isn’t that simple: our memory isn’t just a recorder. Research has shown something spooky: at very high blood-alcohol concentration (BAC) levels of 0.16% or more, people can remember things that just happened – what they said a minute ago, who they were talking to – but later on, they have no memory of it at all (Felton, 2025). In other words, while alcohol leaves your short-term memory intact, your long-term memory is affected, which shows that alcohol-induced blackouts stem from a disruption in the consolidation of memories from short-term to long-term memory. You might remember that you drunkenly made out with your ex in the club when you talk to your friends about it immediately afterward, but you will have forgotten about it in the morning. While in some cases forgetting might be a good thing, it can also be scary, especially if you do not have friends that were with you the entire time to fill you in on the blanks. When you miss memories, you essentially miss a part of your life. Who knows what could have happened? Maybe you went skinny dipping in an Amsterdam canal or ended up sharing your deepest secrets with strangers.
The neurobiology behind a blackout is based on a few critical parts. Alcohol is a depressant, meaning that it slows down your brain activity by increasing the inhibitory neurotransmitter GABA. This increase in GABA activity leads to an inhibition of the brain’s communication systems (Perlmutter, 2024). The activity in the hippocampus, the brain area responsible for consolidating memories, is especially inhibited. Depending on how strongly your hippocampus is affected, you might lose just a part of your night or entire chunks.
“When you miss memories, you essentially miss a part of your life.”
In a fragmentary blackout, you might remember parts of the night: your head in a toilet while someone holds up your hair, or worse, not making it to the toilet and having everyone stare at you. Complete blackouts are called en bloc blackouts, where entire chunks of your day are gone (Wetherill & Fromme, 2016). But why does one person have a blackout after one beer while others take shots the entire night without one?
Different factors influence the possibility of having a blackout. For one, drinking a lot of alcohol in a short period of time increases your BAC quickly. If you want to keep your memories, say no to drinking games or be lame and play water pong instead. Other influential factors are lower body weight, drinking on an empty stomach, and combining alcohol with smoking weed (Richards, 2023). Additionally, the higher your tolerance, which is the amount of alcohol needed to feel its effect, the more likely you are to have a blackout. This is because a higher tolerance often makes people consume larger amounts of alcohol, which in turn increases the risk of reaching the blackout BAC level of higher than 0.16% (Richards, 2023).
“While having one blackout might feel like a funny story later on, making them a habit can cause serious damage to your brain.”
While having one blackout might feel like a funny story later on, making them a habit can cause serious damage to your brain. There are long-term effects of frequent and heavy alcohol use, as regular disruption of hippocampal activity leads to impaired cognitive function and memory over time (Nall, 2025). In fact, chronic drinking is a risk factor for a type of dementia called Wernicke-Kosakoff syndrome (WKS), which is due to the interference of alcohol with the absorption of vitamin B1 (Nall, 2025). After having had a few blackouts, your contextual memory shows impaired activity more strongly the next time you drink compared to that of a person without a history of blackouts (Wetherill, 2012).
All in all, it is your decision what matters more: a fun night out or your memory. Just know that you can have a both, as long as you pay attention to eating before drinking, pacing your drinks, and not smoking weed after alcohol (yes, even if you’re an Amsterdammer). And if you end up waking up with a black hole in your mind, make sure to consult your friends and find out if you did end up skinny dipping or making out with your ex. Would be good to know.
