Indiana University-Purdue University Indianapolis researchers found that mice bred to crave large amounts of alcohol were more impulsive than mice that consumed little or no alcohol. The rodents' impulsivity was tested by giving them the choice between a small, immediate reward and a large, delayed reward. The heavy-drinking mice were more likely to choose the small, immediate reward.

The study appears online and in the July print issue of the journal Alcoholism: Clinical & Experimental Research.

"It is well-documented that humans with alcohol problems have impulsivity issues," Dr. Nicholas Grahame, an associate professor of psychology at the university's School of Science, said in a news release from the university.

"High impulsivity, when defined as the tendency to choose small instantaneous rewards over larger delayed rewards -- like getting drunk instead of going to work for that paycheck in two weeks -- is more prevalent in alcoholics than in non-alcoholics," he said. "Because these mice had never had alcohol, we were able to show that it was the genes that increase drinking, rather than drinking itself, that yielded impulsive behavior."

Grahame said the mouse study can be applied to people "and strongly suggests that impulsivity contributes to high alcohol drinking."

As a result, he said, "the diagnosis of any disorder associated with impulsivity, such as attention-deficit disorder or bipolar disorder, is cause for concern about future problems with alcoholism."

More information

The U.S. National Institute on Alcohol Abuse and Alcoholism has more about alcohol problems.