One in Five Kids with ADHD May Be Misdiagnosed
September 23, 2010
Some 4.5 million children in the U.S. are currently diagnosed with attention deficit hyperactivity disorder (ADHD), and parents of many others may worry that their children are suffering from the condition. But two recent studies point to the possibility that some children who are younger than their classmates are tagged with ADHD simply because of their immaturity.
In the first of the two studies, both published in the Journal of Health Economics, researchers from Michigan State University looked at information on nearly 12,000 kids nationwide. They looked at how ADHD diagnosis and rates of medication use differed between the youngest and oldest children in a grade. The result: Some 900,000 children may be incorrectly diagnosed with ADHD. The very youngest children in grades 5 and 8 were also twice as likely to take stimulant medication to treat ADHD.
This is worrisome, according to study author Todd Elder, a Michigan State University economist, because the effects of long-term stimulant use are still unknown.
The second study, conducted at North Carolina State University, Notre Dame and the University of Minnesota, came to similar conclusions, after looking at kids born shortly before and after the age cutoffs for kindergarten. (In a state where kids have to turn 5 by September 1 to enter kindergarten, for example, kids born in late August or on September 1 would be the youngest in their class, while kids born on September 2 would be the oldest, turning 6.)
The researchers looked at data from the National Health Interview Survey (NHIS), a second survey on medical spending, and insurance claims and found that kids born just before the age cutoff for kindergarten—young compared to their classmates—were twice as likely to be diagnosed with ADHD than the kids who were the oldest in their class.
Another intriguing possibility is that older kids are underdiagnosed. However, researchers of the second study believe that current evidence suggests ADHD overdiagnosis is the more likely, or bigger, problem.
Sources: Elder, TE. "The Importance of Relative Standards in ADHD Diagnoses: Evidence Based on Exact Birth Dates." Journal of Health Economics, Sept 2010; Press release, Michigan State University; and Evans, Morill and Parente. "Measuring inappropriate medical diagnosis and treatment in survey data: The case of ADHD among school-age children." Journal of Health Economics, September 2010. DOI:10.1016/j.jhealeco.2010.07.005.
Please go to Kid's Health News for more information for parents and caregivers.
