In people suffering from mild to moderate depression, extracts of the plant Hypericum perforatum, also known as St. John’s wort, can provide effective relief, similar to that achieved with standard antidepressants but with fewer side effects, a new review of published research indicates.

Researchers from Germany, led by Klaus Linde of the Centre for Complementary Medicine in Munich, reviewed 29 studies involving a total of 5,489 patients with depression that compared treatment with extracts of St. John’s wort for 1 to 3 months with placebo treatment or standard antidepressant medications.

The studies came from a variety of countries, tested several different St. John’s wort extracts, and mostly included patients suffering from mild to moderately severe symptoms of depression, according to the research team.

“Overall, we found that the St. John’s wort extracts tested in the trials were superior to placebos and as effective as standard antidepressants, with fewer side effects,” Linde said in a written statement.

The reviewers point out that the study findings were “more favourable” to St. John’s wort in studies conducted in German-speaking countries where these remedies have a long tradition and are often prescribed by doctors. In studies from other countries, St. John’s wort extracts “seemed less effective,” they report.

The findings are published in the Cochrane Library, a publication of the Cochrane Collaboration, an international organization that evaluates medical research.

In the report, the investigators urge patients who are thinking of using a St. John’s wort product to talk to their doctor first. “Using a St. John’s wort extract might be justified,” they write, but the products on the market “vary to a great extent” and these extracts can sometimes compromise the effects of other medications.

SOURCE: Cochrane Library 2008.