Teens who binge on alcohol damage brains

In human and rodent teens, youthful exposure to alcohol can produce devastating effects on still-developing brains - and decision-making skills down the road.

A recent study by researchers at the University of Washington found that adolescent rats (30 to 49 days old) allowed to binge on a gel containing 10 percent ethanol exhibited poor judgment three weeks after being cut off following a 20-day binge.

Compared to a control group of similar rats denied alcohol, the party animals were much less adept in a test that let animals pick and choose levers delivering either a consistent food reward or less certain payoffs.

Ilene Bernstein, a psychology professor and co-author of the study, published in The Proceedings of the National Academy of Sciences, noted that scientists "believe regions of the brain, including those implicated in decision-making, are slow to develop and development extends into adolescence. This study shows that these late-developing structures in rats are affected by alcohol use."

She noted that exposure to drugs at an early age is the top factor predicting substance-abuse problems later in life. "If the brain is permanently changed by alcohol, we need to place more emphasis on preventing adolescent alcohol use."

A study on human teens reported earlier in the year by scientists at the University of California, San Diego, showed that the concern is well-founded.

The scientists matched up 28 teens, half with a history of binge drinking, the other half nondrinkers similar in age, gender and education, and used an MRI scan to look at differences in the development of "white matter" in their brains. Binge drinking was defined as episodes of taking four or more drinks in females or five or more in males.

Other research has shown that abnormalities in white matter can lead to a compromised ability to consider multiple sources of information when making decisions and impair emotional function, among other problems.

The study found the teen drinks all had "lower coherence of white matter fibers, suggesting poorer white matter health, in a variety of brain regions," compared to the nondrinkers, said Susan Tapert, an assistant professor of psychiatry who co-authored the study.

There are other side effects from binging.

Another mouse study, published last month in a British immunology journal, showed that consuming a lot of alcohol over a short time inhibits the body's ability to fight off infection for at least 24 hours.