A study shows the youngest children in kindergarten are more likely to be diagnosed with attention deficit hyperactivity disorder in early grades. It's an intriguing finding for parents on the fence about when to start their child in school.
The study found younger students, especially boys, are also more likely to be started on medications for it and kept on the drugs longer. ADHD medications are generally safe, but can have harmful side effects.
Researchers say doctors should be aware of how classroom comparisons shape diagnosis.
The paper was published Wednesday by the New England Journal of Medicine.
About 6 million U.S. children and teenagers have been diagnosed with ADHD, which causes inattention, hyperactivity and impulsivity. The rate of diagnosis is climbing.