A new study has found that an extract of the herb Rhodiola rosea has an anti-depressant effect in people suffering from mild to moderate depression.
The research represents the first double-blind, placebo-controlled trial of Rhodiola rosea in patients diagnosed with depression. The results, published in the Nordic Journal of Psychiatry, demonstrate that Rhodiola rosea extract was significantly more effective in relieving symptoms of depression that placebo.
The study was carried out by the Swedish Herbal Institute in Gothenburg, Sweden, using a proprietary Rhodiola rosea root extract called SHR-5, a standardized extract which can be found in their Arctic Root® product.
A total of 89 people suffering from mild to moderate depression, aged 18 to 70, were involved in the 6-week trial. All participants underwent psychiatric evaluations and met criteria for clinically significant depression based on both 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). These are the two major tools used in psychiatry for the diagnosis of depressive illness.
All of the study participants were randomly assigned to one of three groups. The first group were given two 170mg tablets of Rhodiola rosea (SHR-5) once per day, the second group were given two tablets twice daily (for a total of 680mg/day), and the final group was given two placebo tablets once per day.
At the end of the 6-week trial all participants were reassessed using the HAMD and BDI scales. The researchers found that both groups given Rhodiola rosea experienced reductions in their scores that were statisically significant. HAMD scores declined from 24.52 to 15.97 in the lower-dose group and from 23.79 to 16.72 in the higher-dose group while BDI scores were reduced from 12.23 to 7.09 and 10.38 to 4.75 respectively. No statisically significant reductions were noted in either score for the placebo group.
As well as the HAMD and BDI data the study's authors also looked at other effects of the treatment by asking participants about specific symptoms before and after the trial. They found that both groups given Rhodiola rosea experienced significant improvements in insomnia, mood swings, and physical symptoms (pain, fatigue etc). Participants in the group receiving the higher dose of the herbal extract also experienced significant improvements in their self-esteem. Those participants given placebo did not experience statistically significant improvements in an of these symptoms.
The study authors conclude that the SHR-5 Rhodiola rosea extract demonstrates "clear and significant anti-depressive activity in patients suffering from mild to moderate depression." They say this is evident from both overall depression levels as well as from the improvements in specific symptoms.
The authors go on to point out that no adverse effects could be detected in either of the groups given the Rhodiola rosea extract. They note that this is in contrast to al pharmaceutical anti-depessants and even other herbal alternatives such as the popular St. Johns Wort which can produce photosensitivity and has been associated with herb-drug interactions, particularly with the pharmaceutical blood-thinner warfarin.
Source: Darbinyan V Aslanyan G Amroyan E Gabrielyan E Malstrom C Panossian A (2007) Clinical trial of Rhodiola rosea extract SHR-5 in the treatment of mild to moderate depression Nord J Psychiatry 61(5):343-348