The herb St. John's wort may help those with major depression just as well as some prescription antidepressants, says a new review written by Klaus Linde, of the Centre for Commplementary Medicine Research at Technical University in Munich, and his colleagues.
The most striking finding, say the authors, was that "trials from German-speaking countries clearly have more positive effects, both compared to placebo and standard antidepressants, than trials from elsewhere."
Although there is some interest in St. John's wort in the U.S., in some countries, such as Germany, doctors commonly prescribe it for mild symptoms.
Linde and his colleagues also wrote a previous review in 2005 in which they concluded that St. John's wort did help mild to moderate depression symptoms. The biggest difference in the new review is that the reviewers included only studies related to major depression, while the older review included all depressive disorders.
Compared to 2005, said Linde, the evidence that St. John's wort works is better now. There is also now evidence that that there are fewer side effects with St. John's wort compared to SSRIs.
Exactly how the herb works is unclear, however, because the extracts contain several different components. In addition, there is no regulation on exactly what components the extracts should contain.
Linde also notes that the products on the market vary considerably as far as quality and potency. The extracts used in the studies, however, were high-quality products with daily extract dosages standardized between 500-1,000 milligrams.
The reviewers conclude that the currently available evidence suggests that St. John's wort extracts are better than placebo and similarly effective as standard antidepressants.
The review appears in the current issue of The Cochrane Library, a publication which reviews and evaluates research in order to draw conclusions about medical practice.