Teens and alcohol may be an even more dangerous match than most people think.
Drinking heavily during adolescence not only can lead to car accidents, date rape and death, but new research claims that booze is bad for the brain, too.
Heavy drinking has great impact on young people, the researchers believe, because - contrary to popular notion - the brain is still developing.
"The frontal lobe, where our brain does things like planning and problem-solving and judgment, is still developing until we turn 16," says Dr Susan Tapert, a psychiatric research fellow at the University of California.
"Drinking heavily during this time could mean lifelong problems," Tapert says.
For starters, the researchers gave a variety of thinking and memory tests to 15- and 16-year-olds, some who had alcohol problems and some who were non-drinkers.
"The alcoholics performed more poorly in trying to remember the information we had just taught them," Tapert says.
"While most of the non-drinking kids remembered 95 percent of the information, the drinkers remembered only 85 percent," she says. "That would be the difference between an A and B grade or a C and D."
But the problems multiply if young kids who booze keep drinking through their teen years. The proof, the researchers say, comes from examinations they did on parts of the brain that conduct mental calculations and memory functions.
The researchers tested women, 18 to 25 years of age, who'd been drinking heavily since adolescence. Along with a group of non-drinkers of the same age, they performed memory tasks while the researchers took pictures of their brains every three seconds using a special brain-imaging device known as a functional MRI.
"The brains of the alcohol-dependent women showed less use of oxygen in some parts of the brain that are critical to working memory and the ability to work with information you are holding onto in your mind - like doing math in your head," Tapert says.
"The alcoholics also showed less use of oxygen in regions of the brain important for tasks like doing mechanical things or using a map," she says. "We didn't have to look hard to see these differences."
The findings appear in February's issue of Alcoholism: Clinical and Experimental Research.
Measurable brain damage
Researchers at the University of Pittsburgh Medical Centre say studies they've done revealed similar memory problems related to adolescent drinking.
For instance, the area of the brain that helps regulate memory, the hippocampus, was 10 percent smaller in alcoholic adolescents than in those who didn't drink, the researchers say. They compared a dozen alcoholic young people, from 13 to 20 years of age, with two dozen abstinent teens.
"We've known that alcohol causes brain damage for a long time, and we used to think it took a long time to do damage, but now we don't think so," says Dr Michael DeBellis, an assistant professor of psychiatry at the University.
"The hippocampus actively matures during adolescence, so it might be that adolescents are more sensitive to brain damage because the hippocampus is still developing," he says. "But, it might also mean that they are more susceptible to treatment."
"The way alcohol affects the brain is a complicated mechanism that deals with not only the effects of alcohol but with the effects of withdrawal," DeBellis says. "That's important because adolescents tend to binge drink."
"The bottom line is, if kids are drinking, they need to stop and get help," he says.
What to do
Teens are watching and imitating, whether they admit it or not, so the first thing parents should do is evaluate their own behaviour. Then, because teens always have needed to take risks, parents need to help them find healthy ways of doing so.