A study of 378,881 subjects aged 4-17 years by the Taiwan National Health Insurance Research Database found that the likelihood of receiving an ADHD diagnosis and treatment was higher for those born in August (the youngest) compared with those who were born in September (the oldest). The researchers conclude that “relative age, as an indicator of neurocognitive maturity, is crucial in the risk of being diagnosed with ADHD and receiving ADHD medication among children and adolescents. Our findings emphasize the importance of considering the age of a child within a grade when diagnosing ADHD and prescribing medication for treating ADHD.”
Influence of Relative Age on Diagnosis and Treatment of Attention-Deficit Hyperactivity Disorder in Taiwanese Children. Journal of Pediatrics, Published online March 10, 2016