By Dulce Zamora
April 17 (CBS HealthWatch)--The popular dietary supplement St. John's wort may not effectively treat major depression, according to a new study published in the April 18 issue of the Journal of the American Medical Association.
"Our study found that there was no difference between St. John's wort and placebo over an eight-week treatment period," study author Richard Shelton, MD, told CBS News. Shelton is a professor of psychiatry at Vanderbilt University in Nashville, Tennessee.
Researchers studied 200 adults with major depression at several academic medical centers in the US. The participants were split up into two groups: one set received St. John's wort, and the other was given placebo (dummy pills). The patients in the St. John's wort group took 900 milligrams (mg) of the herb per day for four weeks, and if they didn't respond to the herbal remedy, their dosage was increased to 1200 mg/day for the remainder of the trial.
Eight weeks after the study began, investigators found no statistical difference between what St. John's wort and placebo did for the depressed patients.
The results suggest that St. John's wort may not be helpful for people with severe depression, says Shelton. "Since there are effective treatments for depression, I would chose [them] first rather than going with St. John's wort."
Joseph Betz, PhD, vice president of scientific and technical affairs for the American Herbal Products Association, does not find the study's results surprising. He says the trial looked at patients with major depression, whereas previous studies have shown St. John's wort to work for people with mild to moderate forms of the mental condition.
"The study was designed to look at something that the herb is not used for," he says. "This is like designing a study to see if aspirin would cure cancer."
In addition, Betz says it would have been better if the trial monitored patients for a longer time period. He also would have liked to have seen St. John's wort compared to not just placebo, but to a proven antidepressant such as Prozac or Zoloft.
Another expert, Lloyd Sederer, MD, director of the division of clinical services for the American Psychiatric Association, praises the study, calling it "methodologically rigorous." He says it does a good job in showing that St. John's wort is not effective for major depression in the population of people studied. The study's subjects excluded patients with mild to moderate forms of depression, those from other health environments (such as those in primary care settings), and people who preferred alternative medicine approaches to traditional treatment.
Sederer says, however, that people who are already taking St. John's wort need not worry if the herb works for them. "If you're on St. John's wort and if you're feeling better, and if you don't seem to have problems with the medication, well then, that's a good thing," he says. "I would urge those people to tell their doctor so that their doctor knows that they're taking this herbal because it can interact with certain prescribed medications, and also because their doctor needs to know that they're suffering from depression, even if it's mild."
Persons who are depressed
or who are thinking about taking St. John's wort are urged to speak with
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