Young adults who do not define themselves as exclusively heterosexual or homosexual are more likely to misuse alcohol than their peers with a more firmly defined sexual orientation, a new study suggests.

“Bisexuals and students whose sexual orientation was in flux reported the heaviest drinking and most negative consequences from alcohol use, such as uncontrolled drinking and withdrawal symptoms,” said researcher Amelia Talley of the University of Missouri. Those groups drank to relieve anxiety and depression at higher rates than students who defined themselves as heterosexual or homosexual, Science Daily reports.

“One possible explanation is that people who aren’t either completely heterosexual or homosexual may feel stigmatized by both groups,” Talley said in a university news release.

The study included more than 2,000 incoming college students, who were followed for four years. The researchers found students who were exclusively homosexual or heterosexual drank at about the same rate, and reported they drank to enhance their enjoyment of social situations. Students who were not exclusively homosexual or heterosexual tended to report more alcohol misuse.

“This suggests that it may be the stressful process of developing one’s sexual identity that contributes to problematic drinking, just as people in any difficult situation in life may turn to alcohol to alleviate stress,” Talley said. “Organizations could put our findings to use by providing a support network to help young people avoid using alcohol to cope with stress as they define their sexual identity.”

The study appears in the Journal of Studies on Alcohol and Drugs.