According to a study released by the University of Michigan, nearly 1 million children in the United States are potentially misdiagnosed with ADHD.
The research was conducted, not by a medical group, but by economist Todd Elder in the Journal of Health Economics (Elder et al. The importance of relative standards in ADHD diagnoses: Evidence based on exact birth dates. Journal of Health Economics, 2010; DOI: 10.1016/j.jhealeco.2010.06.003).
Elder found that the youngest or often the most immature children are misdiagnosed with the ADHD label simply because of their age and exhibited maturity. Elder also found that these children are significantly more likely than their older classmates to be prescribed medications like Ritalin to control their behavior. Using a sample of 12,000 children, Elder examined the difference in ADHD diagnosis and medication rates between the youngest and oldest children in a grade. He found that the youngest kindergartners were 60 percent more likely to be diagnosed with ADHD than the oldest kindergarten children. Elder followed that group of children and found that they were more than twice as likely to be prescribed stimulant medication by the time they reached the fifth and eighth grades.
Currently, about 4.5 million children are diagnosed with ADHD. Elder concludes that about 20 percent or about 900,000 children have likely been misdiagnosed.
In a press release from the University of Michigan, Elder said that such inappropriate treatment is particularly worrisome because of the unknown impacts of long-term stimulant use on children’s health. Elder is also concerned that misdiagnosis wastes an estimated $320 million-$500 million a year on unnecessary medication. He estimates that between $80 million-$90 million of it is paid by Medicaid.
“If a child is behaving poorly, if he’s inattentive, if he can’t sit still, it may simply be because he’s 5 and the other kids are 6,” said Elder. “There’s a big difference between a 5-year-old and a 6-year-old, and teachers and medical practitioners need to take that into account when evaluating whether children have ADHD.”
ADHD has no pathology, no biological marker in the brain that clearly demonstrates its existence. Thus, its diagnosis is always subjective. While teachers are not permitted to make this diagnosis, their perceptions and opinions serve as the initial step to a diagnosis made by a doctor.
“Many ADHD diagnoses may be driven by teachers’ perceptions of poor behavior among the youngest children in a kindergarten classroom,” he said. “But these ‘symptoms’ may merely reflect emotional or intellectual immaturity among the youngest students.”
According to Science Daily, Elder’s paper will be published in the Journal of Health Economics in conjunction with a related paper by researchers at North Carolina State University, Notre Dame and the University of Minnesota that arrives at similar conclusions as the result of a separate study.