BUFFALO, N.Y. -- In a recent study conducted by scientists at the University at Buffalo's Research Institute on Addictions involving 154 heavy-drinking college students whose sexual behavior put them at risk for HIV infection and other sexually transmitted diseases (STDs), there were two expected findings and one surprise.

As expected, an alcohol-focused, motivational counseling intervention reduced both the frequency of students' drinking and the amount they consumed. A similar intervention that focused only on HIV risk reduced the frequency of unprotected sex, but did not reduce the number of sexual partners.

The surprise? The drinking-reduction intervention did not reduce unprotected sex or the number of partners.

The results were published online in September in the American Psychological Association's Psychology of Addictive Behaviors.

"Drinking and risky sex are common among college students," said Kurt H. Dermen, lead investigator on the study and senior research scientist at the RIA. "Although most who drink are light or moderate drinkers, many college students drink heavily on a regular basis. Many also have sex without using condoms and have multiple sex partners, both behaviors that increase risk for STDs."

Dermen is a clinical psychologist and expert on motivational interventions in addiction treatment. His collaborator on the investigation, Sherilyn N. Thomas, maintains a private psychology practice and serves as director of the Psychological Services Center in UB's Department of Psychology.

Alcohol use has often been blamed as one cause of college students' risky sex, Dermen said. For this reason, many researchers and policy advocates have suggested that intervening to reduce heavy drinking might be an effective way to reduce the frequency of unprotected sex in this group. However, that turned out not to be the case in this study.

The finding that an alcohol-focused intervention had no effect on risky sexual behavior suggests that alcohol use among heavy-drinking college students may have little to do with their decisions regarding whether or not to use condoms or to have sex with multiple partners, Dermen added.

Students selected for the study (91 women and 63 men) ranged in age from 18 to 30 and were all unmarried. All described themselves as heterosexual, except for two women who reported being bisexual. The participants were in their first through sixth years of college. Eighty-six percent were white, five percent were Hispanic, and the rest were black, Asian or Native American.

All of the students reported at least one heavy drinking episode in the two weeks prior to starting the study. In the three months prior to the study, 65 percent also used marijuana, 21 percent used hallucinogens, nine percent used cocaine and seven percent used opiates. More than half (55 percent) of the students reported having had at least five sexual partners in their lifetime, and eight percent reported having had an STD. On average, the students reported having sex 38 times during the previous 90 days, with one-third of those intercourse events occurring after alcohol use.

The study adds to existing evidence supporting the use of drinking-reduction interventions based on the motivational interviewing approach to counseling. It also provides encouraging evidence that a brief HIV-focused intervention employing this approach may be useful for reducing the frequency of unprotected sex among college students.

Additional work is needed to investigate whether these interventions would have similar effects with a greater mix of racial, ethnic and sexual-minority college students.

The Research Institute on Addictions has been a national leader in the study of addictions since 1970 and a research center of the University at Buffalo since 1999.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.