Many common therapies for mild to moderate depression can have side effects such as nausea and sexual dysfunction.
The study, published in Phytomedicine, was led by Dr. Jun J. Mao, an associate professor of family medicine, community health and epidemiology at the Perelman School of Medicine of the University of Pennsylvania.
Rhodiola rosea, also referred to as roseroot, has been used in traditional folk medicine to promote work endurance, increase longevity and promote resistance to several health conditions including fatigue, altitude sickness and depression.
Previous studies have suggested that roseroot could enhance mood by stimulating the receptors of neurotransmitters such as dopamine and serotonin in the brain that are involved with mood regulation. Other research also suggests the herb affects beta-endorphin levels in the body.
In what is the first ever randomized, double-blind, placebo-controlled, comparison trial of roseroot extract, the researchers compared its effects on mild to moderate major depressive disorder with sertraline, a commonly prescribed antidepressant therapy.
Depression is both common and debilitating, with more than 19 million Americans estimated to develop the condition each year. Depression is associated with a high risk of suicide and several simultaneously occurring disorders and physical illnesses.
Unfortunately, around 70% of patients with depression have incomplete responses to therapy with conventional antidepressants. These medicines can often have significant side effects that prevent patients from completing a course of treatment.
"Furthermore, many individuals with more mild depressive symptoms weigh concerns over side effects alongside the limited benefits and costs of conventional antidepressant therapy," write the study authors. "Thus, it is not surprising that depressive symptoms are among the most common reasons cited by consumers to choose alternative therapy."
The aim of the current study was to assess the preliminary safety and efficacy of roseroot for treating mild to moderate depression, to find out if the herb could be used as a base for alternative therapy.
Preliminary results suggest herbal therapy may benefit some people with depression
A total of 57 adults were enrolled to participate in the study. Each participant exhibited two or more major depressive episodes, depressed mood or loss of interest in activities for at least 2 weeks, and depressive symptoms such as significant unintentional weight change, fatigue and recurrent thoughts of death.
For 12 weeks, each participant received either standardized roseroot extract, sertraline or a placebo. The researchers measured changes in the participants' depression during this period.
The researchers found that although the participants receiving sertraline were more likely to report improvements in their symptoms by week 12 of their treatment than participants receiving roseroot extract, the differences were not statistically significant.
In comparison with participants receiving a placebo, patients taking roseroot had 1.4 times the odds of improvement, whereas patients taking sertraline had 1.9 times the odds.
However, far more patients receiving sertraline (63%) reported side effects than those receiving roseroot (30%). This finding suggests that roseroot may have a more favorable risk to benefit ratio than sertraline for treating mild to moderate depression.
"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," says Dr. Mao.
The authors acknowledge a number of limitations to the study, most notably the small sample size. "This study was designed to generate preliminary efficacy and safety data to determine sample size estimates for a future, fully-powered study," they argue.
Despite the limitations of this preliminary study, the authors believe their findings suggest that roseroot extract may have modest antidepressant effects in some patients with mild to moderate depression although larger studies will be needed to fully evaluate the benefit and harm of the herb.
"[Roseroot] may be better tolerated than sertraline, which suggests its potential as a treatment alternative for patients who are intolerant to the adverse effects of conventional antidepressants," the authors conclude.
Last month, Medical News Today reported on a study suggesting that telephone-based peer support could be an effective way to help new mothers with postpartum depression.