Martin Paul Whitely And Suzanne Robinson

New research has found the youngest children in West Australian primary school classes are twice as likely as their oldest classmates to receive medication for Attention Deficit Hyperactivity Disorder (ADHD).

Published in the Medical Journal of Australia, the research analysed data for 311,384 WA schoolchildren, of whom 5,937 received at least one government subsidised ADHD prescription in 2013. The proportion of boys receiving medication (2.9%) was much higher than that of girls (0.8%).

Among children aged 6–10 years, those born in June (the last month of the recommended school-year intake) were about twice as likely (boys 1.93 times, girls 2.11 times) to have received ADHD medication as those born in the first intake month (the previous July).

For children aged 11–15 years, the effect was smaller, but still significant. Similar patterns were found when comparing children born in the first three months (July, August September) and the last three months (April, May, June) of the WA school year intake.