A new clinical trial has found that an extract of Rhodiola rosea (Golden root) 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.
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.
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: the Beck Depression Inventory (BDI, scores greater than or equal to 13) and the Hamilton Rating Scale for Depression (HAMD, scores greater than or equal to 21). 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 described as being identical in appearance to the treatment tablets and contained inactive ingredients with 170 mg of lactose.)
There were no statistically significant differences in the average HAMD and BDI 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 mean total HAMD scores (from 24.52 to 15.97 in the lower-dose group and from 23.79 to 16.72 in the higher-dose group), as well as statistically significant declines in mean BDI scores (from 12.23 to 7.09 in the lower-dose group and from 10.38 to 4.75 in the higher-dose group). The subjects in the placebo group did not show statistically significant decreases in either the HAMD or BDI scores by the end of the trial.
The study's authors also measured other effects of the treatment, called secondary efficacy variables. At both dosage levels of SHR-5, people in the HAMD subgroups experienced statistically significant improvements in insomnia, emotional instability, and levels of somatization (the conversion of anxiety into physical symptoms), while such measures did not significantly change in the placebo group. Also, the group given the higher dose of SHR-5 experienced a statistically significant improvement in regards to low self esteem, while the lower-dose group and the placebo group did not experience changes in low self esteem.
The authors concluded that SHR-5 demonstrates clear and significant antidepressive 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.
Alexander Panossian, PhD, research director of the Swedish Herbal Institute and a co-author of the study, noted that all synthetically-derived, conventional pharmaceutical antidepressant drugs have adverse effects. He added that St. John's wort (Hypericum perforatum), a popular herbal antidepressant, has been associated with herb-drug interactions, particularly with the pharmaceutical blood-thinner warfarin.
"Because of this drug interaction problem, there is a big demand for new natural antidepressants," stated Dr Panossian. "We have found that our SHR-5 extract of Rhodiola has a significant anti-depressive effect in human and animal studies, with no effect on the pharmacological activity and concentration of warfarin in blood after their oral administration together with SHR-5. It is a very safe 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 likewise commented on the need for new, safe anti-depression medications. "At least 50% of patients given prescription antidepressants stop them within 3 months due to unpleasant side effects," said Dr Brown (e-mail to M. Blumenthal, November 19, 2007). He cited a recent National Institutes of Health-funded multi-center study in which only 30% of patients responded to citalopram, a standard antidepressant medication. "Many patients have partial responses and are left with residual symptoms," he said.
Dr. Brown stated that this clinical trial on SHR-5 has shown promising results: "Two dose levels of Rhodiola rosea [SHR-5 extract] 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."
According to Dr Panossian, the SHR-5 Rhodiola rosea extract is already widely used and trusted in some areas of the world. "Four hundred million daily doses have been sold in the last 20 years in Scandinavia, where Rhodiola (notably SHR-5) is used as an adaptogen in cases of decreased performance, such as fatigue and sensation of weakness."
This study was funded by the Swedish Herbal Institute.
Darbinyan V, Aslanyan G, Amroyan E, et al. Clinical trial of Rhodiola rosea L. extract SHR-5 in the treatment of mild to moderate depression Nordic J Psychiatry 2007;61(5):343-348 [Abstract]