A recently released study has found that St. John's Wort, an herbal supplement believed to decrease depression, may not be as effective as once thought in treating moderate to severe cases of depression.
Scientists believe these findings will make patients more aware of the deficiencies of herbal supplements.
"I hope [this study] will reinforce in people with serious medical problems to be more cautious about using alternative medicine," said Dr. Robert Califf, co-author of the study and director of the Duke Clinical Research Institute.
In the largest study to date on the subject, 450 people with major depressive disorders at 12 U.S. medical centers were randomly given St. John's Wort, a placebo or sertraline--a commonly prescribed antidepressant.
After being observed for 12 weeks, patients were followed for six months following treatment.
The results, which were published in the Journal of the American Medical Association, report no statistically significant differences among the effectiveness of St. John's Wort and the placebo. The results suggest that St. John's Wort cannot be used to treat major depression.
However, despite these findings, researchers believe the supplement will still be consumed.
"I'm sure [St. John's Wort] will continue to be used, but I don't think it will be used for serious cases of depression," said principal investigator Dr. Jonathan Davidson, director of Duke's program in anxiety and traumatic stress.
St. John's Wort is one of the most widely used complementary medicines taken to combat depression. However, within the past 10 to 20 years, the divide between mainstream and complementary medicine has been narrowing.
"We are now at a point in which it has become increasingly more important to know, regardless of whether the medicine is mainstream or alternative, if it works or not," Califf said.
"There has been excitement or concern, depending on with whom you speak to, regarding the effectiveness of alternative medicine for people with moderate to severe depression."
The research also elucidated previously undocumented side effects of St. John's Wort, which include swelling of the extremities, increased urinary frequency and difficulty achieving orgasm.
However, the study did not test whether the supplement is effective in treating cases of minor depression.
Since St. John's Wort is categorized by the Food and Drug Administration as an herbal supplement, it is not subject to government regulation.
Researchers express caution over the use of supplements due to lack of FDA oversight. "The thing people need to know about St. John's Wort is that it's not necessarily safe to take, even though it is an herbal supplement," Davidson said.
Beyond the apparent ineffectiveness of St. John's Wort in treating severe depression, previous studies have shown that it has adverse effects on therapeutic drugs for other major illnesses, such as AIDS and cancer.
"All herbal supplements are not automatically suspect, but people who are taking these things need to keep themselves informed about the possible interactions that may exist," Davidson said.
"Your best bet is to go to your doctor and get a professional evaluation from someone who is qualified."
Up to 70 percent of the population with depression will never be diagnosed or professionally treated, while 20 percent of people worldwide will become depressed at some point in their lives.
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