For the 7 percent of American kids who suffer from attention deficit hyperactivity disorder (ADHD), relief may come in the form of green fields, leafy trees and open sky.
Andrea Faber Taylor and Frances Kuo, researchers at the Human Environment Research Laboratory at the University of Illinois at Urbana-Champaign, have found that spending time in ordinary "green" settings—such as parks, farms or grassy backyards—reduces symptoms of ADHD when compared to time spent at indoor playgrounds and man-made recreation areas of concrete and asphalt. The findings were consistent regardless of the child's age, gender, family income, geographic region or severity of diagnosis.
The study builds on the lab's previous finding that adding grass and trees to the grounds of public housing developments is linked to fewer reports of domestic violence and stronger neighborhood ties.
In the study, parents rated their child's behavior after extracurricular and weekend activities. The Illinois team controlled for the effect of physical exercise on hyperactivity, so that the improved symptoms weren't simply a reflection of kids burning off their pent-up energy. Children with attention deficit disorder (ADD)—who were not hyperactive—also had fewer symptoms after playing outdoors. In a follow-up experiment, children who spent 20 minutes on a guided outdoor walk saw the greatest benefits when they walked in smaller groups or one-on-one, compared to those who walked in larger groups. Kuo suggests this may be because in a smaller group, children are not competing for a teacher's attention, awaiting their turn or resisting the distractions of other kids—making them more relaxed.
The findings are especially important because of the increased rate at which kids are being diagnosed with ADHD, says Kuo. The Mayo Clinic estimates that more than 7 percent of children suffer from the neurological disorder. "In nearly every classroom there's a child who has ADHD," Kuo says. "We need to realize that it's a public health problem, not the result of bad parenting."
If doctors eventually prescribe "green time" for the treatment of ADHD, it has the advantage of being widely accessible, free of side effects, nonstigmatizing and inexpensive, Kuo says.