The stress of adult life can make living with undiagnosed ADHD very difficult, doctors say. Jing Wei for NPR hide caption

itoggle caption Jing Wei for NPR

The American Academy of Pediatrics recommends that children have no more than two hours a day of "screen time." Marilyn Nieves/ hide caption

itoggle caption Marilyn Nieves/

Ten milligram tablets of the prescription drug Adderall. The drug is used to treat ADHD and is used by some students to boost their academic performance. Jb Reed/Bloomberg via Getty Images hide caption

itoggle caption Jb Reed/Bloomberg via Getty Images

Eliminating junk food from a child's diet is usually not enough to effectively treat attention deficit disorders, a paper shows. Tarah Dawdy via Flickr hide caption

itoggle caption Tarah Dawdy via Flickr