Youngest children in class more likely to get ADHD medication, study says

The youngest children in class are more likely than their older classmates to receive medication for ADHD (attention deficit hpyeractivity disorder), a study has found.

The Western Australian study, published in the Medical Journal of Australia, has again raised concerns children are being misdiagnosed with the psychiatric disorder and medicated for what could simply be age-related immaturity.

As a new school year looms in Australia, the study has also added to the debate about the best age for a child to start kindergarten.

“Allowing parents to decide when their child is ready for school could prevent misdiagnosis,” lead researcher Martin Whitely said.

“Alternatively, the greater age range within a class that occurs when there is increased flexibility may increase the late birthdates effect. Unless we do the research we simply won’t know the answer to this important question.”

Researchers at Curtin University compared the proportion of WA children in the early and late months of a recommended school year intake who received at least one prescription for an ADHD medication in 2013.

Among the children aged six to 10, those born in June – the last month of a recommended school year-year intake – were about twice as likely to have received ADHD medication than those born the previous July.

For children aged 11-15, the effect was less marked “but still significant”.

“Similar differences were found when comparing children born in the first three (or six) months and the last three (or six) months of the school year intake,” the authors wrote.

Delayed school entry is much less common in WA than other Australian states but the results were consistent with four large-scale northern hemisphere studies, the study authors said.

“Similar findings in north America indicated that developmental immaturity is mislabelled as a mental disorder and unnecessarily treated with stimulant medication,” the authors wrote.

ADHD normally manifests itself in three ways – inattention, impulsivity and overactivity.

Nick Kowalenko from the Royal Australian and New Zealand College of Psychiatrists said there was insufficient detail in the research, but there was cause for concern.

Prescribing antipsychotic drugs for children as young as six was always done with great care and after thorough discussions with the parents, he said.

“Because the guidelines are actually pretty tight most practitioners actually use them. There must be some maverick practitioners and rogue prescribers but they would be very few.”

Diagnosing ADHD can be complicated because it can mimic or occur with other conditions, including autism.

But the diagnosis criteria were very well refined, Kowalenko said. “The question is: does everybody follow them accurately?”