Researchers have found that youths who take their first drink of alcohol before their 15th birthday are at greater risk of developing alcohol-use disorders as adults, a new study finds.

The authors followed three groups of participants (ages 15 and under, 15-17, and 18 and older), noting their first incidence of alcohol dependence, rates of alcohol abuse, and specific alcohol-use disorder criteria.

"The key finding of this study was that people who started drinking before age 15, and to a lesser extent those who started drinking at ages 15 to 17, were more likely to become alcohol dependent as adults than people who waited until 18 or older to start drinking," said researcher Deborah Dawson of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). "Past studies have often suggested that this association might result from common risk factors predisposing people to both early drinking and [alcohol-use disorders]. Although the current study does not provide conclusive evidence that early drinking directly increases [alcohol use disorder] risk, it suggests that it is premature to rule out the possibility of such a direct effect."

The findings will be published online in the December 2008 issue of the journal Alcoholism: Clinical & Experimental Research.