Herbal Cure's Worth Questioned
Findings on St. John's Wort and Depression Revive Old Debate
By Shankar Vedantam
Washington Post Staff Writer
Wednesday, April 10, 2002; Page A08
St. John's wort, the widely used herbal remedy, appears ineffective for treating patients with moderate depression, according to researchers who conducted the most comprehensive study of the substance.
The study, which immediately triggered controversy and criticism, is meant to serve as a guide to millions of Americans who use the herb. An estimated $140 million worth of pills, tablets and preparations with St. John's wort were sold last year in the United States.
"The primary message of this particular study is St. John's wort does not seem to help patients with major depression with moderate severity," said Stephen E. Straus, director of the National Center for Complementary and Alternative Medicine, which spearheads research into alternative medicine at the National Institutes of Health. "That's the form of depression that warrants careful professional attention and for which many patients self-medicate with St. John's wort."
The $6 million, government-funded trial promises to raise more questions than answers, however. While clearly the most important scientific findings to date, the results are confusing and lend themselves to different interpretations. Instead of settling a long-running dispute, the study renewed debate over the substance's usefulness.
Supporters of St. John's wort immediately criticized the study, charging that it was flawed and a waste of money. One scientist who helped design the trial and is now a private consultant said it could not be used to draw any useful conclusions. "It was basically a failed study," said Jerry Cott, a psycho-pharmacologist who has worked at the National Institute of Mental Health and the Food and Drug Administration. "FDA would throw it out."
Previous trials have met with similar criticism. Studies that found St. John's wort useful were criticized by many mainstream scientists as not being rigorously conducted. Studies that found it ineffective were criticized by herbal advocates, who noted that the patients in these studies may have just been unresponsive to all treatment. Most of these trials compared St. John's wort against only a placebo, an inert substance.
The new trial also compared St. John's wort to the well-known antidepressant Zoloft. Since Zoloft has been shown to alleviate depression, researchers figured they could contrast its effects against those of St. John's wort.
But when the results were analyzed, the group of patients on Zoloft did no better than those on St. John's wort. The group getting the placebo, in fact, had the largest percentage of people who responded most completely. Straus, who is a physician, agreed that the strange result diminished the power of the study.
Richard Shelton, a psychiatrist at Vanderbilt University, who published a study last year about St. John's wort, said that researchers may not have used high enough doses of Zoloft to see proper results.
Sales of St. John's wort have fallen steeply in recent years, down by more than half from the 1998 high of $300 million, said Grant Ferrier, editor of Nutrition Business Journal in San Diego.
The study, which involved 340 patients at 12 sites, examined patients who were depressed enough to withdraw from some of their work and hobbies, but not so severely ill as to contemplate suicide. The tablets used contained an ingredient from the St. John's wort plant. The study was published in today's edition of the Journal of the American Medical Association.
Jonathan Davidson, a psychiatrist at Duke University and the lead investigator, said that while neither Zoloft nor St. John's wort did better than the placebo on the primary measure of the study, the conventional antidepressant did better than both the placebo and the herbal product on a secondary measure.
"As far as the patient is concerned, if you fail on the primary and succeed on the secondary, it means the treatment worked," he said.
Supporters of St. John's wort, who include some psychiatrists and the herbal products industry, lashed out at these conclusions and accused the researchers of selectively focusing on results that fit their preconceived opinions.
"It's part of the mind-set of people who work in the field that the herbal product is suspect," said Mark Blumenthal, a medicinal chemist at the University of Texas at Austin and the founder of the American Botanical Council, a group that researches herbs. "Both products failed -- only one got the headlines as being a failure. Both products have been shown in previous studies to be effective. This study doesn't invalidate Zoloft -- it certainly doesn't invalidate St. John's wort."
Herbalists agreed that St. John's wort shouldn't be used to treat people with serious depression. They said studies evaluating the herbal product among these patients were a waste of resources.
Norman Rosenthal, a psychiatrist at Georgetown University and the author of "The Emotional Revolution," said he has successfully used St. John's wort to treat people with mild depression -- a group that the federal government plans to study next with St. John's wort.
"To say it's useless, discard it, or it's great, doesn't do it justice," he said. "We have a fascinating herb with a very long history of therapeutic benefit. . . . [To] view it in polarized terms is to do a disservice to a potentially valuable treatment and the people it might serve."
© 2002 The Washington Post Company
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