Dec. 9, 1999 (Urbana, Ill.) -- Extracts of the herb St. John's wort can safely help mildly depressed people beat the blues, according to research to be published in the Dec. 11 issue of the British Medical Journal. But while the herb extract was more effective than placebo, it fared no better than imipramine, a tricyclic antidepressant used widely in Europe that is available only by prescription.
Depression affects nearly one in ten Americans each year, costing the nation up to $44 billion in treatment costs and lost productivity. The American Psychiatric Association estimates that depressed individuals have a greater than 80% chance of being successfully treated.
But some people don't seek medical help because of the stigma involved, and seek to self-medicate with St. John's wort and other remedies. In addition, extracts of the herb are widely prescribed in Europe, and in Germany they are prescribed more than any other antidepressant. But clinical trials that have purported to demonstrate the effectiveness of St. John's wort remain disputed because some researchers say they were not properly designed.
To settle the question, Karl-O Hiller of the Steiner Arznelmeitel in Berlin and his colleagues compared the effects of St. John's wort extracts, imipramine, and a placebo on 263 moderately depressed people.
The patients took three capsules a day of the herb extract, the prescription drug, or a sugar pill, and all pills were adjusted to look and taste the same. After eight weeks, the doctors judged the extent of the patient's depression using a questionnaire called the Hamilton depression rating scale that measures depressive symptoms.
St. John's wort extract eased depressive symptoms significantly more than placebo pills and to about the same extent as imipramine, the authors write. And both the herbal remedy and the drug improved the patients' scores on a questionnaire that gauged quality of life. According to the researchers, St. John's wort extract "may thus be considered as an alternative first choice treatment in most cases of mild to moderate depression without psychotic symptoms."
Other experts called the study encouraging, but in some ways inconclusive. "What's important is the fact that St. John's wort is better than placebo after eight weeks, and that certainly is encouraging for concluding that St. John's wort extract is effective in [treating] depression, at least for the short term," says Benedetto Vitiello, MD, of the National Institute for Mental Health, who is coordinating a study comparing St. John's wort with the antidepressant Zoloft (sertraline hydrochloride).
Vitiello also notes that the St. John's wort used in the study may not even be available in the U.S. In Germany, St. John's wort extracts and other herbal remedies are carefully regulated by government agencies. But no such controls exist in the U.S. because of a 1994 law that forbade the FDA regulating so-called natural products like St. John's wort.
"It's like tea or coffee -- there is a different concentration of ingredients," Vitiello says. "That is the major risk for the consumer -- they don't know what they're buying."
- In a European study, extracts of the herb St. John's wort worked just as well as a tricyclic antidepressant in treating mild depression.
- Current trials in the U.S. are examining how St. John's wort fares against the widely prescribed antidepressant, Zoloft.