June 11, 2008 -- Despite widespread hope among harried parents that St. John's wort could cure their children's attention problems, a new study says the popular herbal supplement seems to have no effect on the mood disorder.
St. John's wort has been used for centuries as a kind of wonder drug, useful in treating anything from mental conditions to nerve pain, to wounds and burns; the herb was even used in ancient Greece to rid the body of evil spirits.
Today, St. John's wort remains one of the most popular and commonly purchased herbal supplements in the United States. However, like many other types of herbs and herbal supplements, St. John's wort is often used inappropriately to treat health conditions that it hasn't necessarily been proven to treat.
A study released Tuesday suggests that St. John's wort is not a useful treatment for one of the many mood disorders it has been linked to: attention deficit hyperactivity disorder, or ADHD.
Researchers at Bastyr University in Seattle, Wash., studied 54 children between 6 and 17 years old who have ADHD. What they found was that St. John's wort fell short when it came to improving the children's attentiveness or hyperactivity, when compared to the effects of a placebo.
Over-the-Counter Silver Bullet?
According to Wendy Weber, the lead study investigator and research associate professor at Bastyr University, the reason her team began this study was because of the high reported use of St. John's wort to treat ADHD in children.
"We are definitely the first group to evaluate the use of St. John's wort for ADHD, and our decision to do so was based on the fact that the public was using it that way," Weber said.
Although Weber and her team reported that the herb was safe for children to use and caused no serious side effects, their study seems to provide hard evidence against the use of St. John's wort for the treatment of ADHD.
Because the herb has a sedative effect on people, St. John's wort has been linked in recent years to the treatment of depression, anxiety disorders and even ADHD. And despite the lack of scientific evidence to support this link between St. John's wort and mood disorders, such as ADHD, this rumor has renewed public interest in the herb.
Preliminary studies suggest that St. John's wort might work in treating depression by blocking nerve cells in the brain from absorbing the chemical messenger serotonin, which plays a large role in depression and anxiety disorders, but has no significant impact on ADHD.
But several large studies seem to put an end to this theory. A study published in the Journal of the American Medical Association in 2002 found that St. John's wort was no more effective for treating major depression than placebo.
And because St. John's wort acts on serotonin levels -- which have no impact on ADHD -- many experts remain baffled that this myth about the use of St. John's wort still exists at all.
"In essence, this is like saying Prozac does not treat ADHD," said Dr. Michael DeLaHunt, chief of the division of psychology and psychiatry at the Nemours Children's Clinic in Jacksonville, Fla. "My response would be, 'And so what? I never expected that it would.'"
Sketchy Herbal Remedy
Yet, many U.S. adults spend hundreds and even thousands of dollars on the supplement each year, hoping that the herb could be an easy over-the-counter cure for their mood disorder.
"This study showcases the fact that the American consumer uses dietary supplements in a way that is inconsistent with the scientific indications which have been studied," said Dr. Nicole Nisly, director of the complementary medicine program at the University of Iowa. "The average U.S. user uses dietary supplements based on advertisements, and is unfamiliar with the reliable information on supplement use."
In fact, a study published in the journal Mayo Clinic Proceedings in 2007 found that roughly two-thirds of adults who use popular herbs and herbal supplements do not do so in accordance with evidence-based indications.
Moreover, herbal supplements such as St. John's wort are not as highly regulated as FDA-approved prescription drugs, which are subject to strict quality control measures before entering the market. For this reason, experts urge consumers to use the herb only for those indications that it has been proven to treat.
"Much less is known about using wort than using the FDA-approved medicines. Its adverse events are not well understood -- thus, caution is advised," said Michael Manos, head of the Pediatric Behavioral Health Center at the Cleveland Clinic's Children's Hospital.
According to the National Institutes of Health, the most common modern-day use of St. John's wort is for the treatment of depression, regardless of the conflicting evidence on whether the herb actually decreases symptoms of mood disorders at all.
And despite the fact that the NIH says there is not sufficient scientific data to recommend St. John's wort for children under the age of 18, more and more parents each year buy the supplement in hopes that it will help their child's mood disorder.
"Parents of children with ADHD are desperate to find something to help their children," Manos said. "This is one less place to look."