The long-awaited government-sponsored study on the effectiveness of the popular herb is being published this Wednesday, April 10 in the Journal of the American Medical Association. The study, conducted by researchers at Duke University and 11 other medical centers in the U.S., concludes that neither St. John’s wort nor the drug sertraline showed any measurable benefit in patients with more severe forms of depression. Although the study was conducted in patients with moderate to severe depression, the herb has been tested and used mainly in patients with less severe forms of depression.

The study conducted from December 1998 to June 2000 included 340 moderate to severely depressed patients that were randomly assigned to three groups. Over an eight-week period, one group received a dose between 900–1500 milligrams of a leading brand of St. John’s wort extract, one group took the antidepressant drug sertraline (50–100 mg), popularly know by its trade name Zoloft®, and the third group took a placebo, a sugar or dummy pill. Patients who responded to treatment continued to receive their assigned treatment for an additional 18 weeks. Curiously, fewer of the patients in both the herb and the drug groups responded to the treatments than did those in the placebo group.

According to Jerry Cott, Ph.D., former Chief of the Psychopharmacology Research Program, at the National Institute of Mental Health, the NIH designed this trial to include a standard anti-depression drug (sertraline) as "an active comparator" to document the sensitivity of the trial, that is, the ability of this trial to detect an actual treatment effect. "The fact that the sertraline was not effective in the primary measures of depression demonstrates (according to the NIH’s own design protocol) that this trial lacked assay sensitivity and should not be considered a successful study." Dr. Cott was involved in the original design of the trial when he worked for the NIMH.

He added that "this study does not invalidate the use of SJW in clinical depression. There are still many well-controlled trials supporting the use of St. John’s wort in mild to moderate depression, and additional studies with more appropriate patient populations are in progress."

In Dr. Cott’s estimation, this study could be considered "neutral", one that simply fails to show effectiveness of either treatment rather than proving the test drug doesn’t work. "This result is not uncommon in pharmaceutical industry-sponsored studies, though normally they are not published. The study simply lacked the sensitivity to detect a difference." Dr. Cott is an expert on the effects of herbs and conventional drugs on mental disorders, including depression. He also formerly worked at the Food and Drug Administration where he evaluated clinical studies on new antidepressant drugs. (More information available at jerrycott.com.)

Dr. Steven Bratman, a physician-author in Fort Collins, Colorado agrees "The conclusion of the study is taken too far. Both treatments have been found effective in the majority of clinical trials. This study, while not supporting the use of St. John’s wort, doesn't discredit it either."