More than 30 percent of American adults have abused alcohol or suffered from alcoholism at some point in their lives, and few have received treatment, according to a new government study. Alcoholics who got treatment first received it, on average, at about age 30 - eight years after they developed dependence on drinking, researchers reported.

"That's a big lag," especially combined with the fact that only 24 percent of alcoholics reported receiving no treatment at all, said study co-author Bridget Grant of the National Institute on Alcohol Abuse and Alcoholism.

The treatment rate for alcoholics was slightly less than the rate found a decade earlier. The study did not look at reasons for the decline, but other research has revealed a belief among doctors and the public that treatment doesn't work.