A government survey says 1 in 10 U.S. children has ADHD, a sizable increase from a few years earlier that researchers think might be explained by growing awareness and better screening.
ADHD, or attention deficit hyperactivity disorder, makes it hard for kids to pay attention and control impulsive behavior. It's often treated with drugs, behavioral therapy, or both.
The new study found that about two-thirds of the children who have ADHD are on medication.
The estimate comes from a survey released Wednesday that found an increase in ADHD of about 22 percent from 2003 to the most recent survey in 2007-08. The Centers for Disease Control and Prevention interviewed parents of children ages 4 through 17 in both studies.
In the latest survey, 9.5 percent said a doctor or health care provider had told them their child had ADHD. The earlier study found that fewer than 8 percent of kids had been diagnosed with it.
Researchers calculate about 5.4 million kids have been diagnosed with ADHD, which suggests that about 1 million more children have the disorder than a few years earlier.
One expert found it hard to believe that so many kids might have ADHD. "It sounds a little high," said Howard Abikoff, a psychologist who is director of the Institute for Attention Deficit Hyperactivity and Behavior Disorders at New York University's Child Study Center.
Other studies have suggested more like 5 percent of kids have ADHD, and there are no known biological reasons for it to be on a recent increase, he added.