CHICAGO – St. John’s wort, the popular herbal remedy touted as a natural alternative to prescription antidepressants, is ineffective in treating major depression, according to a new study.
Dozens of previous studies, most conducted in Europe, have found some benefit from the herb, which has been used for thousands of years.
But authors of the new report say St. John’s wort shouldn’t even be recommended for those with mild depression without more research.
“We can say with confidence that it calls into serious question the effectiveness in moderate to major depression,” said Dr. Richard Shelton, a psychiatry professor at Vanderbilt University and the lead author of the study in Wednesday’s Journal of the American Medical Association.
The study was funded by Pfizer Inc., which makes antidepressants and St. John’s wort extract. It did not weigh the herbal supplement’s effect on mild depression. A spokesman for a trade group for nutritional supplements says the conclusions are overstated.
“Nobody ever said St. John’s wort was effective for major depression,” said John Cardellina, a vice president with the Council for Responsible Nutrition. “Now these guys run one trial of major depression and say it should outweigh all other trials.”
The researchers studied 200 adult outpatients with major depression at 11 academic medical centers in the United States. Each patient was evaluated for depression and randomly assigned to receive St. John’s wort extract or a placebo for eight weeks. Patients were not permitted to use any anti-depressant drugs.
Researchers concluded that St. John’s wort “failed to produce significant differences vs. placebo” based on previously established scales to rate depressed patients. Dr. Shelton said his study was limited because it did not compare the use of St. John’s wort to an anti-depressant drug. Such a study is being conducted by the National Institutes of Health.
Dr. Shelton criticized previous studies as poorly designed, having too few participants or using inadequate doses of anti-depressant medicines to which St. John’s wort was compared. He said it was inconceivable that so many trials – there have been at least 31 – all were positive.
Dr. Darrel Regier, director of the American Psychiatric Association’s research division, said previous reports of St. John’s wort’s effectiveness might be attributed to a placebo effect – some people will get better simply by believing it works. He said the study shows St. John’s wort should not be recommended for anyone who is depressed.
