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St.
John's Wort Not
So Great For Depression
NEW
YORK (Reuters Health) - St. John's wort may be flying off of health
food store shelves, but new research suggests its purported effects
against depression may not be worth much.
A body of
evidence suggests that the herbal supplement, used for more than
2,000 years to quell mood problems, does help symptoms of depression.
In Germany, where many of the positive studies have been conducted,
St. John's wort is available as a prescription antidepressant.
However, according
to a report in the April 18th issue of the Journal of the American
Medical Association, much of the evidence of the herb's effectiveness
comes from studies of questionable quality. For example, many
studies have not used standard tests for depressive symptoms,
while others have followed patients for only a short time.
To try to
address these shortcomings, researchers followed 200 adults with
major depression for 8 weeks, during which time they took either
St. John's wort or an inactive placebo. By the end of the study,
more than one quarter of those on the herb had improved on a standard
test of depressive symptoms--but so had nearly 19% of placebo
patients.
Dr. Richard
C. Shelton of Vanderbilt University in Nashville, Tennessee, and
colleagues had about half the patients take 900 milligrams of
St. John's wort per day for 4 weeks. If they had not responded
after 4 weeks, their daily dose was increased to 1,200 milligrams
for the remainder of the study.
``These results,''
writes Shelton's team, ``do not support significant antidepressant
or antianxiety effects for St. John's wort when contrasted with
placebo in a clinical sample of depressed patients.''
But for the
average consumer of St. John's wort, this study is ``irrelevant,''
said Dr. Joseph M. Betz of the American Herbal Products Association
(AHPA) in Silver Spring, Maryland. The AHPA is a trade group for
the herbal products industry.
Studies have
shown that St. John's wort fights mild to moderate depression,
not the major depression studied in this trial, Betz said in an
interview with Reuters Health. In the US, he noted, the supplement
is promoted only as a mood enhancer.
``There are
dozens of studies that show (St. John's wort) is effective against
mild to moderate depression,'' Betz said. ''Major depression needs
to be treated by a medical professional.''
Shelton's
team, he said, was ``looking at the wrong thing.''
According
to Shelton and his colleagues, this study was the first large-scale,
scientifically rigorous trial of St. John's wort as a treatment
for major depression conducted in the US. It was funded by the
drug maker Pfizer, which markets antidepressant drugs, as well
as St. John's wort extract.
The researchers
do acknowledge that their findings are not the final word on the
herb. For one, they note, patients in this study had suffered
from major depression for more than 2 years. People whose symptoms
are milder or have set in more recently--as well as those who
simply prefer alternative medicine--may have different responses,
they write.
But until
more ``well-designed'' trials are completed, Shelton and his colleagues
conclude, ``there currently is no credible evidence to support
the efficacy of St. John's wort for people with depression.''
SOURCE:
Journal of the American Medical Association 2001;285:1976-1986.
Reference
Source 89
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