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An
extract of a yellow wildflower called St. John's Wort is taken by many
Americans for depression, often without consulting a doctor. Companies
who sell it say it promotes a positive mood and emotional well-being.
Many studies have found it effective for clinical depression, but physicians
say more evidence is needed, particularly for St. John's
Wort, sold in pill form and as a tea, is widely used as a mood-booster.
Its reputation took a hard hit in 2002, upon publication of a large National
Institutes of Health-funded study. The study, which found the plant extract
no better than a placebo for treating major depression, followed a U.S.
trial published in 2001, which found it ineffective. But a review
published late last year by the Cochrane Collaboration concluded that
St. John's Wort is better than a placebo for major depression and "similarly
effective" to standard antidepressants, with fewer side effects. While St.
John's Wort flopped in the two U.S. trials, "the overall evidence
looks a little different," says the Cochrane review's lead author
Klaus Linde, a physician at the Center for Complementary Medicine Research
at the Technical University of Munich. The Cochrane Review looked at 29
trials with 5,489 patients, mostly from non-U.S. countries. Side effects
of the extract were generally not worse than placebo, Dr. Linde says. Doses vary,
often ranging from 500 to 1,200 milligrams a day. In the U.S., a monthly
supply could cost as little as $3 to $20 or more. "I have
no question that St. John's Wort works in mild to moderate depression,"
says Dr. Brenner, chairman of psychiatry at St. John's Episcopal Hospital
in Far Rockaway, N.Y. He recommends standard antidepressants for major
depression, given the mixed trial evidence and the elevated risk of suicide
in those patients. Many physicians
remain skeptical of St. John's Wort, even for minor depression, because
many positive studies on it come from German-speaking countries, such
as Germany, Austria and Switzerland. The reasons for the more positive
results in those countries aren't known, says Dr. Linde. He says the German
patient populations may be different, perhaps depressed for less time
than U.S. patients. Most of the trials in German-speaking countries also
were funded by makers of St. John's Wort products, while the two major
U.S. trials weren't, Dr. Linde says. "It's
hard to totally discount the evidence out of Europe, but it's a bit puzzling
that we haven't been able to replicate the results here," says Sheila
G. Jowsey, assistant professor of psychiatry at the Mayo Clinic in Rochester,
Minn. If you do take St. John's Wort, it's important to tell your physician. Even more than many herbals, it is known to interfere with the efficacy of standard medical therapies, including cardiac medications and anti-rejection drugs taken by transplant patients, says Dr. Jowsey. There is also a risk that St. John's Wort might interfere with the efficacy of contraceptives, but that hasn't been proved, says Dr. Linde.
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