Ineffective alternative

Researchers find St. John’s Wort does not lessen ADHD symptoms

Nearly 4.5 million American children ages 4 to 17 suffer from attention-deficit/ hyperactivity disorder, according to the Centers for Disease Control and Prevention. Because not all these children respond to medications such as Ritalin or Adderall, some parents turn to herbal supplements to treat the symptoms associated with the neurobehavioral disorder.

NO FLOWER POWER Caption: For years parents whose children suffer the symptoms of ADHD have looked for effective treatments. Pharmaceutical drugs do not always work, so some parents turn to herbal remedies, such as St. John’s Wort. John Hayes

But a new study, led by Wendy Weber, a physician specializing in naturopathic medicine and a professor at BastyrUniversity in Seattle, is one of the first to rigorously test one of these herb-based medicines. Weber’s team reports that children suffering symptoms of ADHD show no improvement in attentiveness when treated with St. John’s Wort extract. The results appear in the June 11 Journal of the American Medical Association.

“There are a lot parents who have concerns about having their kids take stimulants such as Ritalin,” Weber says. “Reading the literature you can see why they are hesitant. Stimulants are strong medications, and parents at my practice hesitant to use them unless they have to.”

St. John’s Wort is a yellow-flowered plant whose medicinal uses were first recorded in ancient Greece. In 1997, scientists in Germany showed that taking extracts of St. John’s Wort can inhibit the reuptake of brain chemicals such as serotonin and norepinephrine.

Medications used to treat ADHD have the same inhibiting effects on brain chemicals. Blocking the uptake of the chemicals seems to result in improvement in ADHD-diagnosed children’s ability to pay attention, Weber says. The children also are less hyperactive.

In the last 10 years, the FDA approved Strattera, a non-stimulant drug that blocks norepinephrine uptake. Weber and her colleagues hypothesized that extracts from St. John’s Wort might affect the brain in the same way as Strattera. Since reports were coming in that parents might be trying to treat ADHD with St. John’s Wort, Weber and her colleagues wanted to see if the plant extract actually did have an effect in treating symptoms of the disorder.

The researchers conducted the first-ever randomized, placebo-controlled clinical trial designed to treat children diagnosed with ADHD with St. John’s Wort. Fifty-four participants ranging in age from 6 to 17 participated in the study. The researchers randomly assigned 27 children to receive 300 milligrams of 0.3 percent hypericin. Hypericin is one of two compounds derived from the St. John’s Wort flower and leaves. Researcher think hypericin is the active ingredient that affects brain chemicals, Weber says. The dose is the standard level thought to be effective.

The other 27 children received a placebo filled with rice protein powder and activated charcoal to match the color of the St. John’s Wort pill. The researchers told the participants to take the respective pills three times a day for eight weeks, and not to take any other ADHD medications during the study.

To measure the changes in attentiveness, researchers used the psychiatrist-developed ADHD Rating Scale-IV and the Clinical Global Impression scale. Using these diagnostic tools, the researchers can rank improvement in behavior on a scale of 0–54 and 0–7, respectively.

The study found no statistically significant improvement in the behavior of children given the hypericin versus those given the placebo. On the ADHD rating scale, for example, inattentiveness improved, on average, 2.6 points for the children taking the experimental treatment. The behavior improved 3.2 points for those taking the placebo.

Weber says for FDA-approved medications such as Strattera and Ritalin, the improvement in attention increases by 10 to 15 points on the ADHD rating scale. She also notes that in clinical trials researchers tend to see what they call the placebo effect, where participants show improvement even though they are not receiving medication.

“This study was well done,” says Eugenia Chan, a developmental-behavioral pediatrician at Children’s Hospital Boston. “It was a small study, and it is possible that with a much larger sample of patients you might find that there is some positive effect of St John’s Wort.”

But, she adds, this study is the first of its kind for St. John’s Wort.

“It is important to keep in mind that herbs and supplements are not always safe or well-studied. They can have side effects, and they are not regulated to the degree that pharmaceutical drugs are,” Chan says. “Because of the lack of regulation, the potency can differ from pill to pill within the same bottle.”

One possible reason for the results is that the hypericin in the pills used in the study may have degraded over time, Weber says. This problem could also affect the St. John’s Wort pills currently on the market, the team reports.

She says that if researchers want to retest St. John’s Wort and its effect on ADHD, they will have to figure out how to keep the compound from degrading. As for she and her colleagues, they will choose another alternative medicine to run clinical tests on.

“People deserve to know and be able to understand the potential risks and benefits to all treatments they may be considering,” Chan says.

Currently, physicians are better able to explain the risks and benefits of FDA-approved drugs, such as Ritalin, because a large research base exists for these types of medications.

“There isn’t the same accumulation of high quality evidence for most complementary and alternative medicine therapies. This study used rigorous methodology to study one of those therapies,” Chan says, “and I hope it inspires others to do the same.”

photo of Ashley Yeager

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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