August 28, 1998

Multi-center study to test effectiveness of St. John’s Wort

Multi-center study to test effectiveness of St. John's Wort

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St. John's Wort has been used as an herbal medicine for 2,000 years and, over the past century in Europe, to treat anxiety and depression.

It's the plant's use as a treatment for depression that's now spurring its popularity in the Unites States. Up to this point, however, there has been inadequate testing to prove whether it is, in fact, effective.

That will change in September, when Vanderbilt University Medical Center begins enrolling patients in a six-month, multi-center study to test the effectiveness of St. John's Wort in treating depression.

Dr. Richard C. Shelton, associate professor of Psychiatry and principal investigator of the study, said there have been more than 30 studies of the herb, but all have been flawed.

"It's been widely reported in the media that St. John's Wort is the most extensively studied anti-depressant in history. The reality is that since it is an herb and not regulated by the FDA, health food stores and folks selling it on the internet can make any kind of claim they want," Shelton said.

St. John's Wort is a bushy perennial that contains a variety of chemicals, the most significant of which is hypericin — named after the botanical name for the plant, Hypericum Perforatum.

Recent estimates show nearly one million people in the United States use St. John's Wort. According to Shelton, about 50 percent of these people suffer from significant depression, which has about a 1 percent annual mortality rate. Therefore, assuming that approximately half of these people seek treatment if St. John's Wort fails, it is conservatively estimated that more than 1,500 people could die annually of suicide if St. John's Wort is not an effective treatment.

"If this herb is being used in the United States for the treatment of depression and it really doesn't work, then lots of people are dying and it's a major public health problem," Shelton said.

Shelton was approached by the National Institutes of Health to participate in a large, multi-center study that would take four years to complete. He declined.

"We needed a study completed sooner than that," Shelton said.

So he approached a pharmaceutical company that makes a leading anti-depression medication and asked them to fund an independent St. John's Wort study. Although the drug company funds the study, it does not control the results.

VUMC will be the administrative site of the study.

The study will be double-blinded and placebo-controlled, meaning that neither the patient nor the staff will know whether the patient is getting St. John's Wort or a placebo. The patient will receive either a refined preparation of the herb or the placebo for eight weeks of active treatment. At the completion of the eight weeks, the study will be unblinded and any patients doing well with St. John's Wort will continue to receive the herb for six months. Anyone not doing well with the herb will be given an anti-depressant drug for the six months.

"We're going to assure everybody of active treatment," Shelton said. "We're going to try and answer this question once and for all in a high-quality study. My goal is to take an herbal product that is widely used and widely recommended worldwide and really give it a rigorous test — the same way we would any other kind of treatment.

"There are all kinds of wild claims being made about all sorts of herbal products. My desire is to reconnect the American public with what's been referred to as evidence-based medicine."

Twenty patients will be enrolled in the study at VUMC. Nationally, 200 will participate.

To be accepted for the study, a person must be moderately to severely depressed and be 18 or older. Both men and women will be accepted, although depression is twice as common in women.

"My feeling is that if it's an effective anti-depressant drug, we ought to be using it because it appears to be quite safe," Shelton said. "But if it's not effective, then nobody should be using it. There are so many good anti-depressant drugs that there is absolutely no excuse to be promoting something that's not effective."

Suicide isn't the only risk, Shelton said. For patients suffering from depression, not improving is equally risky.

"Because depression is often longstanding it often impairs function in ways people just get used to," Shelton said. "They get used to not enjoying things in life. They get used to not performing well on their job. They get used to not being a good parent because they're tired all the time. And they don't even necessarily recognize the degree to which they are impaired."

"So if they continue to take St. John's Wort and it really doesn't work, they will continue not only to run a risk of killing themselves, but also of experiencing the risk that everybody with depression faces — impairment of day-to-day function."

For more information, call study coordinator Linda Todd-Lingley at 343-9664.