A Q&A with researcher Frances Kuo on the impact of outdoor "green time" on children and adults with attention deficit disorder (ADHD).
What's your new study about?
Frances Kuo: Before the current study, we were confident that acute exposures to nature — one-time doses — have short-term impacts on ADHD symptoms. Brief exposure to green outdoor spaces can improve concentration and impulse control in children and adults. The question is, if you're getting chronic exposure, but it's the same old stuff -- your backyard, say -- does that help?
So does it?
FK: Yes. Those who play regularly in the same green outdoor settings do have milder symptoms than those who play indoors or in playgrounds. We also found that children who were hyperactive had less severe symptoms if they played in an open environment, such as a soccer field, rather than in a green space with lots of trees.
How much green therapy does a child need?
Andrea Faber Taylor: We can't say that two hours of outdoor play will get you this many days of good behavior. We can say that as little as 20 minutes of outdoor exposure in an open green space could potentially buy you a couple of hours in the afternoon to get homework done with your child.
How does nature moderate ADHD symptoms?
FK: In one study we did, in 2008, children generally concentrated better after a walk in the park than they did after the other two kinds of walks -- in a "green" downtown area and in a residential neighborhood. The greenest space was best at improving attention. We don't know what it is about the park -- the greenness or the lack of buildings -- that seems to do the trick, but a dose of nature may be as helpful, at least for a while, as a dose of stimulant in increasing attention.
Based on your research, what should parents do?
AFT: Try nature out for themselves. Take their child to the park, either when his symptoms are severe or as a regular routine. There’s little risk involved and, possibly, much to gain.
Frances Kuo, Ph.D., and Andrea Faber Taylor, Ph.D., are child environment and behavior researchers at the University of Illinois.