St. John’s Wort Helps Some Patients With Major Depression

The herbal medicine St. John’s wort appears to work just as well as some prescribed antidepressants for treating patients with major depression, a new review finds. However, patients in German-speaking countries might experience the best benefits.

While there is public interest in the United States about whether St. John’s wort adequately treats depression, in some countries, like Germany, doctors commonly prescribe it for mild symptoms. Authors of the review found that studies with German patients did, in fact, have the best results.

“The most striking finding from our review is that trials from German-speaking countries have clearly more positive effects, both compared to placebo and standard antidepressants, than trials from elsewhere,” said lead reviewer Klaus Linde of the Centre for Complementary Medicine Research at Technical University in Munich. “In principle, we can say that hypericum extracts work in German-speaking countries, but we are less certain for other countries.”

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

A person could be experiencing major depression when depression symptoms interfere with his or her ability to work, sleep, eat and take pleasure in activities previously enjoyed. The symptoms usually last for at least two weeks, but can often last longer than several months. St. John’s wort (an extract of the plant Hypericum perforatum L.) is an herbal alternative for patients who do not want prescribed antidepressants.

Exactly how the herb works to treat depression is unclear, partly because the extracts can contain at least seven groups of components, according to the reviewers. There is also no regulation on what the extract must contain.

“There is no patent protection on herbs; therefore, more or less anyone can market hypericum extracts,” Linde said. “The products on the market vary enormously in their quality and content in active ingredients.”

Linde added that consumers should be aware that many St. John's wort products on the market have very low concentrations (such as dosages of less than 300 milligrams per day), and therefore, probably act only by placebo effects.

In the United States, the National Center for Complementary and Alternative Medicine (NCCAM), a division of the National Institutes of Health, reports that St. John’s wort is “of minimal benefit in treating major depression.” A study co-funded by NCCAM, found St. John’s wort to be no more effective than placebo in treating major depression of moderate severity.

Linde and his colleagues wrote a previous Cochrane review in 2005 on St John’s wort and concluded that it did reduce symptoms of mild to moderate depression. The significant difference between the 2005 review and the current one is the reviewers now include only studies restricted to major depression, while the older version included all depressive disorders.