Have you noticed that children who are closer to the deadline in age for school entry are more likely to be medicated for attention-deficit hyperactivity disorder (ADHD)? Vuori et al (10.1542/peds.2019-4046) evaluated whether there is an association between birth month and initiation of ADHD medications in children enrolled in the Finnish school system. The authors looked at three years of children born in 2005-2007 (N= 182, 802) and classified a child as having new-onset ADHD based on the first fill of an ADHD medication. Finnish children start school in the year they turn 7 years of age. In this study, there was an increase in ADHD medication use associated with children with later birth months qualifying for school entry among both males and females between September and December. The authors conclude that age immaturity relative to the age cutoff for starting the school year increases the likelihood of ADHD medication use in those children with later birthdays—or does it?
An accompanying commentary (10.1542/peds.2020-022798) by Dr. Eric Butter, Chief of the Division of Psychology at Nationwide Children’s Hospital, raises a number of concerns about the strength of this association found in this study by Vuori. Dr. Butter, for example, notes that labeling a child with ADHD may not necessarily be what the child has, but more reflective of a teacher hoping that ADHD medication will help a child who is less mature in their class. Dr. Butter notes the age of the Finnish dataset (2012-2014) for school enrollment as being before the AAP rolled out its clinical practice guidelines for ADHD (2019). These guidelines call for multidimensional input before giving a child the diagnosis of ADHD. Using teachers’ input only is not sufficient to establish the diagnosis of ADHD. Because so much has changed since this study period regarding recommendations for diagnosing ADHD, the study’s generalizability is lowered. Still, Dr. Butter points out that this study is an important reminder for all of us to not automatically think ADHD unless we consider the “relative age effect” and the biases that go with it. The commentary by Dr. Butter will remind you that age should not be the sole deciding factor in making the diagnosis of ADHD when compared to the diagnostic criteria as listed in the latest clinical practice guidelines from the AAP. Pay attention to both this study and commentary and it may make you even more accurate in your diagnosing of those children who truly meet the working definition of ADHD.
