Most of us know that feeling the morning after the night before when we wake up and say 'never again'.
Scientists have now discovered the area of the brain that gives us that hangover feeling - and suggest it is vital to stopping us drinking too much, too often.
The part of the brain is known as the lateral habenula. Researchers believe it is activated by bad experiences and that when it is faulty or underactive, people may be more inclined to repeat unhealthy behaviour.
Read more: Twelve bizarre hangover cures
Neuroscientists at the University of Utah hope their discovery could lead to better treat alcoholics.
The research, published in the journal PLOS One, looked at rats given access to a strong alcoholic drink over a period of several weeks. The animals which had a disabled lateral habenula drank more heavily than those which did not.
Professor Sharif Taha, who led the study, said: "These rats drink amounts that are quite substantial. Legally they would be drunk if they were driving.
"It's the same kind of learning that mediates your response in food poisoning. You taste something and then you get sick. If we can understand the brain circuits that control sensitivity to alcohol's aversive effects, then we can start to get a handle on who may become a problem drinker."
- Daily Mail