N E W Y O R K, April 17, 2001 -- The popular herbal supplement St. John's wort is no better than a sugar pill in treating depression, a new study says.
In a study of 200 depressed patients performed at 11 academic medical centers throughout the country, researchers found St. John's wort provided no advantage over a placebo, or sugar pill, in alleviating symptoms.
Patients recruited for the study were diagnosed with major depression but "moderate" symptoms. Such people experience a mixture of a down mood, a loss of interest in life, sleeping problems, appetite loss, hopelessness and suicidal thoughts, but their ability to function is only beginning to become impaired.
Patients with "mild" symptoms are deemed depressed but can function normally. Patients with "severe" symptoms are impaired in a major way.
St. John's Wort Is Widely Used
A plant with yellow flowers that commonly grows wild, St. John's wort, or Hypericum perforatum is sold in health food stores, pharmacies and groceries as a natural way to improve mood.
Although American consumers in 2000 bought fewer herbal supplements than they did in the 1999 boom year, sales for do-it-yourself pick-me-ups — such as St. John's wort, s-adenosyl-methionine (SAM-e) and kava kava — still approach $400 million a year, according to Consumer Reports.
Since St. John's wort is marketed as a nutritional supplement and not a drug, the Food and Drug Administration does not regulate its production. As a result, consumers cannot be sure they are getting a defined dosage. Any side effects also are not listed on the packaging.
First Published Study to Show No Antidepressant Effects
In the study of 200 adult outpatients diagnosed as having major depression, 98 were randomly assigned to take a dosage of 900 milligrams of St. John's wort for four weeks, increased to 1,200 milligrams in the absence of an adequate response. The other 102 people received a placebo for 8 weeks.
Using psychological rating scales to measure symptoms of the depression, the researchers found no significant difference between the two groups during the study period. Pfizer, Inc., which manufactures the antidepressant Zoloft, provided support for the study.
"These results do not support significant antidepressant or antianxiety effects for St. John's wort when contrasted with placebo in a clinical sample of depressed patients," the authors say.
The study is the first published one to show no benefit of St. John's wort for major depression, says Dr. Richard Shelton, lead author and professor of psychiatry at the Vanderbilt University in Nashville, Tenn.
Researchers: May Help Less Depressed People
Other studies, Shelton says, which may have shown a benefit for St. John's wort did not use rigorous standards to measure depression or were too small to say there were statistical significance between the St. John's wort and comparison groups.
The findings are reported in the current issue of the Journal of the American Medical Association.
The researchers say St. John's wort was well tolerated, except for some patients who experienced headaches. Since patients experienced few adverse reactions, the researchers say more research needs to be done to see if patients with less severe depression may benefit from the herbal supplement.
Other Studies Coming
The federal National Institutes of Health is conducting a study comparing St. John's wort, placebo and the antidepressant Zoloft. Results are expected sometime this year.
Experts are looking towards the results of the NIH study because the Vanderbilt study by some statistical fluke may have included patients that would not have responded to any medication, an unlikely, says Shelton, but possible occurrence.
"I think most people will reserve final judgment on the issue of St. John's wort effectiveness until after the NIH study is done, although this study will be and important component in making such a judgment," says Randy Juhl, dean of the school of pharmacy at the University of Pittsburgh.