Drinking may take big toll on teen brains

Teenagers have been drinking alcohol for centuries. In pre-Revolutionary America, young apprentices were handed buckets of ale. In the 1890s, at the age of 15, the writer Jack London regularly drank grown sailors under the table.

For almost as long, concerned adults have tried to limit teenage alcohol consumption. In the 1830s, temperance societies administered lifelong abstinence pledges to schoolchildren. Today, public health experts regularly warn that teenage drinkers run greatly increased risks of involvement in car accidents, fights and messy scenes in Cancun.

But what was once a social and moral debate may soon become a neurobiological one.

The costs of early heavy drinking, experts say, appear to extend far beyond the time that drinking takes away from doing homework, dating, acquiring social skills and the related tasks of growing up.

Mounting research suggests that alcohol causes more damage to the developing brains of teenagers than was previously thought, injuring them significantly more than it does adult brains. The findings, though preliminary, have demolished the assumption that people can drink heavily for years before causing themselves significant neurological injury. And the research even suggests that early heavy drinking may undermine the precise neurological capacities needed to protect oneself from alcoholism.

The new findings may help explain why people who begin drinking at an early age face enormous risks of becoming alcoholics. According to the results of a national survey of 43,093 adults, published on Monday in Archives of Pediatrics & Adolescent Medicine, 47 percent of those who begin drinking alcohol before the age of 14 become alcohol dependent at some time in their lives, compared with 9 percent of those who wait at least until age 21. The correlation holds even when genetic risks for alcoholism are taken into account.

The most alarming evidence of physical damage comes from federally financed laboratory experiments on the brains of adolescent rats subjected to binge doses of alcohol. These studies found significant cellular damage to the forebrain and the hippocampus.

And although it is unclear how directly these findings can be applied to humans, there is some evidence to suggest that young alcoholics may suffer analogous deficits.