Does your brain work after drinking alcohol

Blackout from alcohol

How did I get here? If the memory of the same is missing after a night of sleep, then one speaks of a blackout, also known as a film tear. What actually happens in the event of a blackout? And is there a certain amount of drink at which a blackout occurs?

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The hotel room is completely devastated. A chicken runs cackling across the hallway and a tiger is sitting in the bathroom. After waking up, the rather hungover-looking men in the US film “Hangover” have no memory of yesterday's night. Obviously they blacked out. Alcohol and certain drugs like GHB, ketamine or Rohypnol are known to cause a blackout. But what actually happens in the event of a blackout?

Brain only partially out of action

Fortunately, not every blackout ends as catastrophically as in "Hangover". The fact is, however, that people affected by a blackout caused by alcohol can usually - depending on the circumstances - still be able to talk and move around. The person just can't remember it afterwards. So it can happen that you suddenly wake up in a place that you don't know how you got there. In the event of a blackout, the brain is not completely disabled, but only partially disabled. First and foremost, it affects what is known as episodic memory, which links information about place, time and other context-related things.

For a long time it was assumed in science that alcohol generally inhibited all neuronal activities in the brain. According to this, a blackout would simply be an extreme form of the depressing alcohol effect. But now, thanks to modern brain research, more is known about the blackout phenomenon. A South Korean research team has reviewed and summarized the research results of the last four decades.

Different blackouts

The fact that we can remember something actually requires three cognitive processes. So-called encoding takes place first: the brain registers and interprets new information. This is then followed by permanent storage in long-term memory. Finally, in order to remember something, the information still has to be retrieved.

In the case of a so-called “en bloc” blackout, a total loss of memory for a certain episode, the first phase of memory formation, i.e. storage, is already disturbed. With fragmented memory loss, people can later remember details by giving them clues or going back to where it happened. In the case of a blackout caused by alcohol, this is often no longer possible because the experience was not saved - as if the episode in question had never occurred.

Malfunction in the hippocampus

And what happens in the brain? Brain research has shown that memory formation primarily takes place in the so-called hippocampus, which is located in the area of ​​the temporal lobe. Based on animal experiments, it is known that high amounts of alcohol cause malfunctions in the hippocampus, with the effect that no information is stored. Researchers at the University of Washington were able to show in animal models that alcohol blocks certain receptors in the hippocampus and activates others. As a result, the so-called long-term potentiation is disturbed. Long-term potentiation is a process in which the connection between neurons is strengthened and enables the formation of long-term memory.

After all, heavy binge drinking can also damage the hippocampus. If teenagers get drunk frequently, their brains can be damaged. The result: learning can be permanently impaired.

Increased risk of accidents

Increased alcohol consumption not only endangers the brain. People who have a blackout are still limited in their ability to act, but they have an increased risk of accidents, as was shown in a study by the University of Wisconsin-Madison in the USA. Over a period of two years, study leader Marlon Mundt and his team followed the drinking behavior of over 900 students. At the beginning of the study, it was recorded how often the students get drunk and how often they have already had a blackout. Two years later it was found that students who had blackouts particularly often had an almost three-fold increased risk of accidents that were directly a result of alcohol consumption.

Blackout risk varies from person to person

Research has not yet been able to give a clear answer to the question of the amount of alcohol above which a blackout usually occurs. So there is no drinking amount above which a blackout will definitely occur. Even with the same person, the amount that blackouts out can vary significantly. Research has shown, however, that the risk of a blackout is particularly high when large amounts of alcohol are drunk in a short period of time - especially when it is high-proof.

There are also people who, despite binge drinking, have never had a blackout, which suggests that genetic differences are also responsible for this. In a study it was shown experimentally that people who had blackouts in the past generally suffer more from memory gaps, even if they drink alcohol moderately, than people who rarely or never have blackouts.

Signs of problematic use

It used to be assumed that blackouts only occur with alcohol addiction, but it is now known that blackouts are quite common and are usually a sign of excessive consumption. In general, frequent blackouts are also a sign of problematic alcohol consumption. Because healthy people change their drinking behavior after a blackout or avoid provoking a blackout again through excessive drinking.


It's impossible to predict if someone will blackout after alcohol. There is no specific drinking amount, but one that will certainly set in a blackout. In general, however, binge drinking and especially the quick drinking of hard liquor are considered to be the risk of a film break. And anyone who has ever had a blackout may be generally at risk of blackout from alcohol.


  • Lee, H., Roh, S. & Kim, D. J. (2009). Alcohol-Induced Blackout. Int J of Environ Res Public Health, 6 (11), 2783-2792.
  • Press release Washington University in St. Louis (July 6, 2011)
  • Tokuda, K., Izumi, Y. & Zorumski, C. F. (2011). Ethanol Enhances Neurosteroidogenesis in Hippocampal Pyramidal Neurons by Paradoxical NMDA Receptor Activation. The Journal of Neuroscience, 31 (27), 9905-9909.
  • Wetherill, R. R. & Fromme, K. (2011). Acute Alcohol Effects on Narrative Recall and Contextual Memory: An Examination of Fragmentary Blackouts. Addictive Behaviors, 36 (8), 886-889.
  • Mundt, M. P., Zakletskaia, L. I., Brown, D. D., & Fleming, M. F. (2011). Alcohol-induced memory blackouts as an indicator of injury risk among college drinkers. Injury prevention, 18 (19), 44-49.