Kids with ADHD may benefit from great outdoors

Kids with attention-deficit hyperactivity disorder who have a few hours on their hands might want to consider heading to the nearest grassy park or tree-lined street.

In a study of several hundred children with the disorder, researchers found that those who spent time in green, natural settings reported fewer symptoms than kids who worked on activities indoors or who took part in activities in more urban areas.

“I think we’re on the track of something really important,” said study coauthor Frances E. Kuo, a psychology professor at the University of Illinois at Urbana-Champaign, who is also a professor in the school’s department of natural resources and environmental sciences. “We’re on the trail of potential treatment.”

The neurological disorder ADHD affects 3% to 9% of the country’s school-age kids, according to a study published in August in the Journal of the American Medical Assn. The disorder can create problems in school and relationships and can lead to depression and substance abuse, the study said.

Drugs such as Ritalin or Adderall are often used to help sufferers focus, but they can have side effects and -- families sometimes feel -- a stigma. As a result, many families prefer to try nonmedical approaches first, although these remain unproven.

Previous studies conducted by Kuo and Andrea Faber Taylor, a postdoctoral researcher at the University of Illinois who specializes in children’s environments and behaviors, found that time in nature helps adults and children without ADHD concentrate. “If it works with other kids, we thought, maybe it will work in kids who have difficulty with attention,” Kuo said.

For the study, researchers recruited 406 participants -- 322 boys and 84 girls -- who had been diagnosed with ADHD. Most of the participants, ages 5 to 18, were on medication.

The parents were interviewed by e-mail about how their children performed after activities conducted inside, outside in downtown areas without much greenery, and in more natural outdoor settings such as a tree-lined street or a park. The researchers asked parents to compare 56 activities and how their children fared afterward.

Regardless of whether they were on medication, children who spent a few hours after school or on the weekend playing outside in green, natural settings showed a significant reduction of symptoms compared with those who had spent time indoors or surrounded by asphalt and pavement, parents reported.

But the study did not quantify how much symptoms were reduced.

“Unfortunately, all we can say is that it [the effect of nature] is a real effect that is big enough that parents were noticing it, and they were not looking for it,” said Kuo, explaining that parents did not know the objective of the questions or the study.

Dr. James McGough, director of ADHD programs at UCLA’s Neuropsychiatric Institute, was skeptical of the study.

“We know that with all behavioral treatments that have been tested with children with ADHD, the positive effect is there only while the activity is being carried out. It doesn’t carry over when the intervention isn’t there,” he said. “There is no reason to believe that children exposed to more green time will do better in the classroom.

“The best you can say is this is an interesting hypothesis that needs to be tested in a scientific manner.”

Dr. L. Eugene Arnold, professor emeritus of psychiatry at Ohio State University in Columbus, said it was too early to tell whether spending time in natural settings holds much promise for kids with ADHD. He pointed out, however, that a kids’ summer program at the University of Pittsburgh, which uses outdoor spaces and a classroom, seemed to be getting good results.

“I would characterize this as an interesting and provocative study which deserves further research,” Arnold said.

Kuo said she and her partner were doing just that. They recently completed a study in which kids were taken on guided walks in different environments on the same day of the week, at the same time, with the same person. Afterward they tested the children’s concentration with objective measures, to move beyond people’s impressions and toward actual performance data. Results have not been published.

Results of the current study appear in the September issue of the American Journal of Public Health.