Hormones may make women more prone to drug addiction than men, new University of Minnesota research shows.

An undergraduate student researcher presented findings last week suggesting that a form of estrogen may give women a greater susceptibility to drug addiction, and some researchers say this work will help develop new addiction therapies in the future.

“We’re hypothesizing that what estrogen is in fact doing, in many respects, is sort of giving a cocktail of stimulation,” said Paul Mermelstein, an associate professor in the Department of Neuroscience and the student’s mentor.

Scientists already knew that women tend to progress much more quickly from casual drug use to addiction than men do, said biology, society and environment senior Ambrosia Smith, who led the research. She conducted the study through the McNair Scholarship program, which offers research opportunities and funding to first-generation or underrepresented college students.

This recent project, one of few studies examining addiction disparities on a biological level, sheds light on why the gender difference exists, Smith said.

And although women usually abuse drugs less frequently than men do, they still experience greater negative effects, said University addiction studies expert Julie Rohovit.

During the study, researchers removed rats’ ovaries, which provided a type of estrogen needed for the experiment. Then they injected the hormone into a part of the brain associated with forming habits, later finding evidence of increased addiction susceptibility.

“If someone was to take cocaine, and this was a woman whose estrogen levels were higher, it’s almost like cocaine with a little bit of marijuana,” Mermelstein said.

The new knowledge will help therapists as they develop fresh techniques for combatting drug abuse, said Jessie Everts, director of clinical services at Wayside House, a facility that helps women in the Twin Cities who are in recovery from drug addiction.

She said the research findings will be welcome news for her co-workers and those using the clinic.

“The women that we’ve talked to are really interested in knowing more about that,” Everts said.

Besides potential hormonal effects, Everts said sexual abuse and other traumas can contribute to higher risks of chemical dependency among women.

And that increased vulnerability is what Mermelstein’s long-term work focuses on. His lab looks at what estrogen circulation does in the brain in regard to addiction, he said, and he’s trying to find new ways to eliminate or decrease women’s susceptibility.

Researchers said Smith’s findings will help scientists better understand biological and hormonal influences on drug addiction.

“When I’m hearing that sex differences are being explored in terms of physiological response, that’s very exciting,” Rohovit said.

Finding her Niche

When Smith transferred to the University of Minnesota from Wesleyan University in Connecticut her junior year, she said she struggled to find her identity.

During that time, she started her own student group called Niche, which is a meeting place intended for women of color in the sciences.

Smith also found that her interests in gender differences and drug addiction research aligned with those of Mermelstein. So she said working with him seemed like a good way to accomplish her research goals and help in her search for identity.

Smith said she chose to pursue addiction research for her McNair program research partly because drug abuse seems to exist everywhere.

“I think drug addiction is prevalent within every community, regardless of where you live or who you are,” she said.