Study douses St. John's wort depression claims
The first large-scale, multi-center study of the effectiveness of St. John's wort in treating moderately to severely depressed individuals has shown that the herbal remedy is not effective.
The double blind, placebo-controlled study, led by Dr. Richard C. Shelton, associate professor of Psychiatry at Vanderbilt University Medical Center, looked at 200 patients at 11 academic medical centers across the United States who had been diagnosed with moderate to severe depression.
The participants in the study were given either 900 to 1,200 milligrams of St. John's wort per day or a placebo for eight weeks. Then, the study was unblinded and patients doing well with St. John's wort received the herb for another six months. Those not responding were given an anti-depressant.
The preliminary results, reported last week at the American Psychiatric Association annual meeting in San Francisco, showed that St. John's wort is no more effective than a placebo in effectively easing the symptoms of depression.
"This study seriously calls into question the effectiveness of St. John's wort in the treatment of the typical depressed patient with a moderate to severe depressive condition. There were statistically no differences between the two groups (St. John's wort and placebo)," Shelton said. "People have been attracted to St. John's wort because it comes from a natural source but our study shows it's a treatment that doesn't work, the most dangerous type of treatment. This is especially true for depression where a significant proportion of untreated patients — 5 to 10 percent — are going to commit suicide."
Shelton said that patients with moderate to severe depression often become disillusioned if their medication is not effective and may be reluctant to try another type of medication.
Shelton said there have been more than 30 studies of the herb, but all have been flawed. In addition, the FDA does not regulate herbs so health food stores and companies on the Internet can make unsubstantiated claims as to their effectiveness.
"If people are out there taking St. John's wort, and it's not working, they may get discouraged and not proceed on to another type of treatment. If this is a really ineffective treatment, and we believe it may well be, based on our data, people need to know this. One of the principal reasons for doing this study is that people were basing their choice of St. John's wort as a treatment on studies that no reasonable researcher in the field would consider valid. We felt it was important for us to step back and take a serious look."
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 that nearly one million people in the United States use St. John's wort. Shelton said that about half of those people suffer from significant depression, which has about a one 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 if it is not an effective treatment.
Those of the 200 participants who did not respond to St. John's wort in the Vanderbilt-led study are continuing treatment with anti-depressants, Shelton said. Most are responding to the treatment.
There are currently two other ongoing large-scale studies of St. John's wort and depression, Shelton said. One of them, being conducted by the National Institutes of Health, should be completed by the end of the year.
"I believe that these studies will collectively answer any questions people have about whether or not St. John's wort is effective in treating depression," Shelton said. "I think the next logical step would be a study of whether St. John's wort is effective in treating mildly depressed patients."