When children start school, there is often a gap in maturity between the oldest students and the youngest in the same grade. This age difference—ranging from 1 to 11 months—may partially explain the rising prevalence of attention-deficit/hyperactivity disorder (ADHD). Researchers in Tapei and Taoyuan, Taiwan reveal that there is a connection between the age children begin school and the likelihood of receiving a diagnosis for ADHD. The study suggests that some of the symptoms commonly associated with ADHD, like impulse control and difficulty sustaining attention, may be the result of immaturity rather than a disorder.
The researchers evaluated cohort data from 378,881 children aged 4 to 17 years from 1997 to 2011, noting how many children were diagnosed with ADHD or prescribed medication for ADHD. They assessed whether age was related to the prevalence of ADHD diagnoses or ADHD-related prescriptions by comparing the rates of both in the youngest students (those born in August) and the oldest students (those born in September), with the oldest students 11 months older than the youngest.
The youngest children in a grade were more likely to receive an ADHD diagnosis or a prescription for ADHD medication compared to the oldest children. This association between age and ADHD prevalence held only for children in preschool and elementary school. Adolescents born in August did not have the same increase in risk for ADHD. This may suggest that the risk for ADHD decreases as students age and mature.
“Our findings emphasize the importance of considering the age of a child within a grade when diagnosing ADHD and prescribing medication to treat ADHD,” concluded study author Dr. Mu-Hong Chen.
This research is published in The Journal of Pediatrics.