A new clinical trial has found that an extract of Rhodiola rosea roots and rhizomes demonstrated anti-depressive activity in patients with mild to moderate depression.

This is the first double-blind, randomized, placebo-controlled study of Rhodiola rosea in patients diagnosed with depression. Patients given the Swedish-made Rhodiola rosea extract showed significant improvements in depression compared to those given placebo.

The trial, published in the Nordic Journal of Psychiatry, utilized a proprietary Rhodiola rosea root extract called SHR-5, a standardized extract used in the product Arctic Root® produced by the Swedish Herbal Institute in Gothenburg, Sweden (distributed in the United States by ProActive BioProducts Inc. of Sedona, AZ (http://www.proactivebio.com)).

The 6-week trial was conducted on 89 subjects, aged 18 to 70, who were assessed with clinically significant depression according to two different standard measurements used in psychiatry. Patients were randomly assigned to one of three groups. The first group received 2 tablets once daily (340 mg/day) of SHR-5, the second group received 2 tablets twice daily (680 mg/day) of SHR-5, and the third group was given 2 placebo tablets once daily. (Placebos were identical in appearance to the treatment tablets and contained 170 mg lactose.)

There were no statistically significant differences in the average depression scale scores among the subjects in the three groups before the herb extract or placebos were given. Following treatment, both groups given SHR-5 experienced statistically significant declines in average scores compared to placebo. The placebo group did not show statistically significant decreases in scores by the end of the trial.

At both dosage levels of SHR-5, people experienced statistically significant improvements in insomnia, emotional instability, and levels of somatization (the conversion of anxiety into physical symptoms), compared to insignificant changes in the placebo group.

The authors concluded that SHR-5 demonstrates clear and significant anti-depressive activity in patients suffering from mild to moderate depression, evident from both overall depression levels as well as from specific symptom levels of depression. They further noted that no adverse effects could be detected in either of the groups given the Rhodiola rosea extract.

Richard P. Brown, MD, associate professor of clinical psychiatry at Columbia University College of Physicians and Surgeons, and a co-author of a comprehensive review of Rhodiola rosea and a book on the subject said, "Two dose levels of Rhodiola rosea were found to significantly reduce symptoms of depression in patients with mild to moderate depression compared to placebo in this randomized clinical trial. In addition to mood elevation, evidence indicates that R. rosea has numerous other benefits, including enhancement of cognitive function, sexual function, and both mental and physical performance under stress. Additional studies are needed to explore and establish the potential applications of this herbal extract. In the meantime, phytomedicinal researchers and consumers can be encouraged by these findings."

This study was funded by the Swedish Herbal Institute.

About the American Botanical Council

Established in 1988, the American Botanical Council (ABC) is the leading nonprofit, member-based international organization working to educate consumers, healthcare professionals, researchers, educators, industry, and the media on the safe and effective use of herbs and medicinal plant products. An extensive review of Rhodiola rosea, its traditional uses, and its scientifically supported modern medicinal properties and uses was published in ABC's peer-reviewed journal HerbalGram in 2002 (Please click here).

American Botanical Council