SUSAN DENTZER: An estimated 18 million Americans suffer each year from depression. And as many as two million are believed to be treating themselves with this. St. John's Wort is a simple yellow wildflower, so named because it blooms in Europe around June 24, or St. John's Day. Extracts of it have been used for centuries to treat depression, including, reportedly, by the roman emperor Nero. It's long been widely used in Europe and caught on in 1990s in the United States. Sold most frequently as an over- the-counter herbal supplement, St. John's Wort has found its way not only onto pharmacy shelves, but also into breakfast cereals, herbal teas and fruit juices.
Dr. Norman Rosenthal is a psychiatrist affiliated with Georgetown Medical Center, and the author of a book on St. John's Wort. He says that the herb contains Hyperforin, one of several substances in the plant that could be active ingredients in battling depression. One or more of these ingredients is believed to function much like conventional antidepressants, such as Prozac and Zoloft, by affecting brain chemicals called neurotransmitters that in turn influence mood.
DR. NORMAN ROSENTHAL: I think "Nature's Prozac" is a fun way of referring to St. John's Wort, and not that out of line.
SUSAN DENTZER: Rosenthal says several dozen of the mildly depressed patients he's treated have used St. John's Wort with good results.
DR. NORMAN ROSENTHAL: For example, someone who had job difficulties, felt irritable and angry with the people at work, it bothered her sleep a little bit, she didn't feel like going to work in the morning, she developed a negative attitude around work. She decided to take St. John's Wort, and within two or three weeks her whole attitude had improved. She wasn't seriously disturbed in any way, but it turned her around.
SUSAN DENTZER: But a study published this week in the "Journal of the American Medical Association" could have a depressing effect on enthusiasm for St. John's Wort.
DR. RICHARD SHELTON: So someone would come in and say, "I've taken the herb and it really didn't help me at all."
SUSAN DENTZER: Dr. Richard Shelton is a psychiatrist at Vanderbilt University and lead author of the new study.
DR. RICHARD SHELTON: I saw enough people, it started giving me some concern that perhaps something was wrong here and that St. John's Wort was not going to be effective for the treatment of depression.
SUSAN DENTZER: So Shelton devised the new study, funded by a $2 million grant from Pfizer Corp., Which produces both Zoloft as well as St. John's Wort supplements. The study examined 200 patients with mild to severe depression who sought treatment at 11 academic medical centers around the country. Half were treated with St. John's Wort, and half were given a dummy pill, or placebo.
DR. RICHARD SHELTON: What we found was that if you looked at the change in the depression ratings over the eight-week period of treatment, there were no differences between active St. John's Wort and placebo.
SUSAN DENTZER: The finding on St. John's Wort was somewhat surprising. It seemed to contradict earlier studies of the herb -- most of them done in Europe. But Shelton says most of those studies were seriously flawed. Some examined too few patients to be statistically valid, or failed to use standard rating tools to judge the how depressed patients were. Although Shelton and his colleagues sought to correct those flaws in their study, they admit that it has one key shortcoming: It only compared St. John's Wort with a placebo, and not with a prescription antidepressant like Prozac. Rosenthal says that research loophole could be plugged later this year. That's when results are scheduled to be published from a major study funded by the National Institute of Mental Health that will compare St. John's Wort to both Zoloft and a placebo.
DR. NORMAN ROSENTHAL: What we will know is whether St. John's Wort is better than placebo, but also how it stacks up against a popular modern antidepressant.
SUSAN DENTZER: In the meantime, there's some evidence that Americans are already beginning to sour on St. John's Wort. Jerome Danoff is a pharmacist in McLean, Virginia.
JEROME DANOFF: I'd say we probably sell three or four a month at the most at this point. We were selling quite a bit a few years ago.
SUSAN DENTZER: In fact, according to the trade magazine "Nutrition Business Journal," U.S. retail sales of the supplements peaked at roughly $300 million in 1998; they fell by almost $70 million the following year. All signs point to an ongoing decline ever since. Some mental health providers, like Rosenthal, say they're still keeping an open mind about St. John's Wort, especially for treating the mildest cases of the blues. But even he says the new study reinforces the view that people with serious depression should absolutely not use the supplement.
DR. NORMAN ROSENTHAL: If you've been depressed for a month or more, if you're not sleeping properly, you're not eating, you're losing weight, you can't get out of bed in the morning, your job is suffering, your relationships are suffering, that is the cluster of symptoms you see in depression. Sometimes people feel hopeless and despairing, see no future or actually consider suicide. If you have those features, don't mess around. Get to a doctor. Get the best treatment by a professional for that condition. Don't self-medicate.
SUSAN DENTZER: And that's likely to be the best advice that mental health professionals can offer for now, at least until it's known for certain how the so-called nature's Prozac really stacks up against the man-made kind.