One in every 10 kids gets diagnosed with ADHD, and 62 percent go on medication for it. That’s a lot of Ritalin. And according to a new study, kids don’t need all that medication to treat the condition. All they need is to spend more time outdoors. The new study suggests that children with ADHD who walked through a park for 20 minutes were just as effective as a dose of medication. Another study found that the greener a child’s play settings are, the less severe their general symptoms are.