Nearly 40 percent of American adults believe in the power of alternative medicine to treat various conditions, from sleep disorders to obesity, and these treatments include everything from popular diets to herbal supplements to meditation. They’re so widely used because sometimes, the benefits of using them outweigh those of using prescription drugs. And now, a new study shows how this could apply to people with major depressive disorder (MDD) who take the the European folk medicine roseroot, also known as Rhodiola rosea.

While there hasn’t been enough scientific evidence to prove its benefits — this is the case with a lot of alternative medicine — it’s been suggested the plant may be useful for people suffering altitude sickness, sexual dysfunction, irregular heartbeats, high blood pressure, and even more serious conditions like cancer and diabetes. The new study supports previous research in finding roseroot may help people with depression as well.

Researchers from the Perelman School of Medicine at the University of Pennsylvania compared roseroot’s effects to those of sertraline, which often goes by the name Zoloft, and a placebo. They found that those who took sertraline were 1.9 times more likely than those taking a placebo to report their depressive symptoms had improved, while those who took roseroot were 1.4 times more likely to report the same.

The researchers said that while sertraline was obviously more effective, the side effects patients felt while on it could offset the benefits when considering roseroot is a viable alternative — albeit only people with mild to moderate depression. Twice as many patients on sertraline reported side effects than on roseroot. They included nausea and sexual dysfunction.

The study was small, however, including only 57 adult participants who qualified for MDD under guidelines provided in the Diagnostic and Statistical Manual of Mental Disorders. All patients had symptoms like weight loss, mood changes, loss of interest, insomnia, inability to concentrate, and recurrent thoughts of death. Each underwent an intervention for 12 weeks with one of the treatment options or a placebo.

“These results are a bit preliminary but suggest that herbal therapy may have the potential to help patients with depression who cannot tolerate conventional antidepressants due to side effects,” said Dr. Jun Mao, an associate professor of family medicine, community health, and epidemiology. “Larger studies will be needed to fully evaluate the benefit and harm of R. rosea as compared to conventional antidepressants.”

Source: Mao J, Xie S, Zee J, et al. Rhodiola rosea versus sertraline for major depressive disorder: A randomized placebo-controlled trial. Phytomedicine. 2015.