June 4 (HealthDay News) -- College students with a "dense" family history of alcoholism have the highest risk of alcohol-use disorders, a U.S. study says.

While most university students tend to "mature out" of heavy drinking by the time they're young adults, some develop alcohol-use disorders, or AUDs. Most genetic research on family history of alcoholism has focused on alcohol use by the parents, most often the father.

But this study found that the density of family history of alcoholism (FHA) is much more effective.

"Using a density measure of FHA can identify a greater number of individuals who may be at risk for developing an alcohol problem. The greater the number of affected relatives, the greater the potential risk of developing an AUD. Ours is the first published study to examine this measure among college students," first author Christy Capone, a postdoctoral research fellow at Brown University's Center for Alcohol and Addiction Studies, said in a prepared statement.

The study included 293 female and 115 male undergraduates from a northeastern U.S. university who completed an anonymous survey.

"Our use of a density measure identified a large proportion of students, about 29 percent, who are at potentially greater risk for development of AUDs based on their report of alcoholism among first- and second-degree relatives," Capone said. "Our other key finding was the relationship between FHA and other potential risk factors -- behavioral undercontrol, age of onset of drinking (AOD), and cigarette use."

"Family density appears to be a promising method to identify a higher percentage of at-risk individuals," John Hustad, a research associate at Brown University, said in a prepared statement. "For example, in this study, approximately 44 percent of the at-risk participants would have been missed if a typical family-history measure had been used instead of the family-history density approach."

Capone said: "It is important to remember than not everyone with density of family alcoholism will go on to develop a long-term problem with alcohol themselves. Alcohol dependence is a very complex disorder, and FHA is but one influence on its development. However, college students who are heavy drinkers and have greater density of familial alcoholism are certainly at higher risk of continuing to drink in a problematic fashion after the college years."

The study was published online in the journal Alcoholism: Clinical and Experimental Research and was expected to be in the August print issue.

SOURCE: Alcoholism: Clinical and Experimental Research, news release, May 31, 2008