A recent study found that child's birth date may predict whether they will be treated for attention deficit hyperactivity disorder (ADHD). Researchers claim that younger children in classrooms were being misdiagnosed with ADHD because they were immature.

The Proportion Of Boys Receiving Medication Was Much Higher Than Girls

Researchers from researchers from Curtin University, Murdoch University and the University of WA followed a study of more than 311,000 Western Australia schoolchildren, and found that the youngest students in a classroom were about twice as likely to be on ADHD drugs than their older classmates, ABC News reported. Out of the study subjects, 5,937 received at least one government subsidised ADHD prescription in 2013. The proportion of boys getting medication (2.9 percent) was much higher compared to girls (0.8 percent).

The study, which was published in Medical Journal of Australia, found that among 6- to 10-year old kids, those born in June - the last month of the recommended school-year intake - were about twice as likely to have received ADHD medication as those born in the first intake month (the previous July).

There is a smaller but still significant effect for kids aged 11 to 15 years. Similar patterns were found when comparing children born in the first three months, or July, August September, and the last three months or April, May, June, of the WA school year intake.

Research Suggests We Need To Throw Away The 'Meaningless Label' Of ADHD Altogether

According to The Sydney Morning Herald, International studies found similar results. In Canada, a population study of almost 1 million showed that boys who were the youngest in their class were 30 percent more likely to be diagnosed with the condition, and 41 percent more likely to be medicated.

Experts say that the problem is that, diagnostic criteria for ADHD were too vague. "To diagnose kids with ADHD we rely on subjective things like whether they're distracted easily, playing too loudly, fidgeting in their seat, disliking or avoiding homework, climbing excessively, and interrupting. Of course we're going to see problems with diagnostic reliability," lead researcher Dr Martin Whitely said.

Dr Whitely said that the "meaningless label" of ADHD should be thrown away altogether. "Sometimes they just need to grow up, sometimes it's trauma, bullying, eyesight, sleep deprivation, poor nutrition, inappropriate teaching styles, they're too bright and bored in class or they're struggling and disadvantaged," he added.