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Clinical Trial on St. John's Wort


The National Institute of Mental Health/National Center for Complementary and Alternative Medicine/ODS Clinical Trial on St. John's Wort

There is considerable public interest in claims that extracts from the herb Hypericum perforatum, commonly known as St. John's wort, may be an effective treatment for depression. Although St. John's wort is widely prescribed in Europe, no studies of its long-term use have been conducted, and published studies have treated different types of patients and have used several different doses. The NIH National Institute of Mental Health (NIMH)external link icon, in collaboration with the  National Center for Complementary and Alternative Medicineexternal link icon  (formerly the Office of Alternative Medicine) and the ODS, is beginning the first U.S. large-scale controlled clinical trial on St. John's wortexternal link icon to assess whether it has a significant therapeutic effect in patients with clinical depression.

This 3-year study, coordinated by Jonathan Davidson, M.D., at Duke University Medical Center, will include 336 patients with major depression, as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Patients will be assigned randomly to one of three treatments for an eight-week trial. One-third of the participants will receive a uniform dose (900 mg daily) of St. John's wort, another third will receive placebo, and the other will take a selective serotonin reuptake inhibitor (SSRI), commonly prescribed for depression.