Partying too hard can damage the sensitive brains of young university students, new research suggests.
Binge-drinking may cause changes in their brains similar to those seen in adult chronic alcoholics, a study has shown.
Young people in their late teens and early 20s are still in the process of wiring up their brains. Scientists fear excessive drinking might impair their neural development.
The researchers monitored electrical activity in the brains of 80 first year students from a Spanish university who were quizzed about their drinking habits.
In self-confessed binge-drinkers they found neural changes that looked like early signs of brain damage.
Lead scientist Dr Eduardo Lopez-Caneda, from the University of Minho in Portugal, said: "These features might be down to the particularly harmful effects of alcohol on young brains that are still in development, perhaps by delaying neuro-maturational processes."
For the study, binge-drinking was defined as consuming five or more alcohol drinks within a two-hour period for men, and four for women.
Students who had participated in at least one such heavy drinking session within the previous month were classified as "binge-drinkers". They were compared with "non-bingers" who claimed they had never binged.
Drinking an amount meeting the bingeing definition would "not equate to a particularly heavy night" for many college students, said the researchers whose findings appear in the journal Frontiers in Behavioural Neuroscience.
Previous studies have linked binge-drinking to impaired mental performance, poor academic achievement, and risky sexual behaviour.
Dr Lopez-Caneda said: "A number of studies have assessed the effects of binge drinking in young adults during different tasks involving cognitive processes such as attention or working memory. However, there are hardly any studies assessing if the brains of binge drinkers show differences when they are at rest, and not focused on a task."
The students had an average age of 18 and attended Complutense University in Madrid. Electrodes were attached to their scalps to take electroencephalogram (EEG) recordings of electrical activity in various parts of their brains while at rest.
In binge-drinkers, significantly higher levels of beta and theta activity were identified in the right temporal and bilateral occipital cortex regions.
Very similar brainwave patterns have previously been seen in adult chronic alcoholics, the scientists pointed out.
The changes may indicate a reduced ability to respond to external stimuli, and potential problems with processing information, they added.
Further work is needed to confirm that the observed abnormalities really are caused by binge-drinking and whether the students' brain development might be impaired, said the researchers.
But the results suggest that binge-drinking has tangible effects on young brains comparable with those seen in alcoholics, they argued.
"It would be a positive outcome if educational and health institutions used these results to try to reduce alcohol consumption in risky drinkers," said Dr Lopez-Caneda.
Dr James Nicholls, director of research at the charity Alcohol Research UK, said: "An increasing body of research shows a difference between adult and adolescent brain function into young people's early twenties, including in response to alcohol.
"It is positive to see that further research is ... being done on a subject which remains poorly understood, and I would welcome the evaluation of this new research by experts in neuroscience.
"It remains the case that binge drinking carries a number of health risks for people of any age, and we would recommend that all drinkers take note of the chief medical officer's guidelines for low-risk drinking, even during Freshers' Week."