Study: St. John's Wort Not Effective In Treating Depression

St. John's wort's popularity first surged in Europe in the '80s, then it spread to the United States.

"It kind of woke us up here to the possibility that here's a treatment for depression that we didn't know much about," Duke psychiatrist Dr. Jonathan Davidson said.

No one knew if the drug really worked, so researchers at Duke University and 11 other centers recruited more than 300 patients with major depression. Some patients took St. John's wort, some took the prescription drug Zoloft, and others took a sugar pill.

"For major depression of at least moderate severity, St. John's Wort is not effective," Davidson said.

In fact, St. John's wort was no more effective than the sugar pill. Davidson said patients took 1,500 milligrams a day, more than enough to see it was not working.

"I think people who were believing a lot in it may obviously have to think again about it," Davidson said.

Davidson said if you think you are depressed, you should see your doctor. There are effective treatments out there for it.

The research does not close the book on St. John's wort and depression. Studies are under way to see if it has any effect on the more milder forms of depression.

There is even another study out this week that said St. John's wort can also keep a common cancer drug from working as well as it should.

The research shows that it can disrupt other drug treatments like those used to treat AIDS, heart disease and seizures. The research concerns doctors since many cancer patients use supplements and other over-the-counter treatments hoping to improve their chances of beating the disease.