Younger Kids Are More Likely to Be Diagnosed with ADHD

Kids born between January and April have an edge over their younger classmates.

Posted Oct 17, 2017

A number of research studies (for examples: here, here, and here) have shown that children who are the youngest in their classroom, born from September through December, are more likely to get a diagnosis of ADHD and be medicated with stimulant drugs than their older classmates. This research was conducted in countries that have generally high rates of the ADHD diagnosis—like the United States and Canada. 

But what about Finland, an advanced country where very few children have ADHD? Finnish researchers were interested in whether younger kids still run a greater risk of being diagnosed. New research from Finland, published on October 6, 2017, in The Lancet Psychiatry, shows that even in countries where ADHD diagnosis is less frequent, it is still given to the youngest children in a classroom.

According to the lead author of the research Kapil Sayal, younger kids run the risk of being incorrectly diagnosed with ADHD merely because they are less mature than their older peers. Sayal writes: 

"Teachers and parents might interpret the behaviour of younger and older children within the same class differently because they might not take relative age into account. This situation could result in a referral and diagnostic bias, meaning that relatively young children within the class are more likely to be clinically referred and subsequently diagnosed with ADHD—possibly incorrectly."

According to Daryl Efron, whose comments on the article were also in The Lancet, relatively young children within a classroom are more likely to be clinically referred and subsequently misdiagnosed with ADHD.

This study is yet another confirmation of the view that children, especially boys, should not be rushed into kindergarten because they run the risk of being misdiagnosed with ADHD. And, if a child has already been diagnosed with ADHD, teachers, parents, and doctors should take the child's relative age into account. They should ask whether the child really has a mental disorder or whether he is simply less mature than his classmates and only appears to have ADHD.