A new study has found that children born in August are more often diagnosed with attention deficit hyperactivity disorder (ADHD) than kids born a month later in September, and researchers have suggested that rather than looking for some kind of biological or genetic basis to explain this strange phenomenon, we should be looking at when we enforce school year cut-offs.

Though researchers are still debating the particulars of ADHD on a general level, many agree that the real problem is how we diagnose the disorder, especially in children. Now, researchers from Taiwan have analysed data from 378,881 children aged 4 to 17, and say schoolyear cut-off months could go some way in explaining why we can't seem to get it right

The study, conducted by a team from Taiwan's National Yang-Mind University, found that since children born in August can be much younger than their classmates due to the schoolyear cut-off, they can appear to have the symptoms of ADHD when they're actually just younger and more immature, reports Kj Dell'Antonia for The New York Times.

The best way to wrap your head around all this is to think about two children that are the same age: one born in August - the last month allowed before the cut-off for a particular school year - and one a month later in September.

When both of these children reach school age, the August child will enter school a full year before the September child, because the September child has missed the schoolyear cut-off, and will be forced to wait till next year to enrol. 

This allows the September child to have a full year of maturing before entering the classroom, while the August child is super-young compared to their other classmates, which makes them stand out.

According to Dell'Antonia, the team's findings are also backed up by a similar study that took place in US which found that "8.4 percent of children born in the month before their state's cut-off date for kindergarten eligibility are given ADHD diagnoses, compared to 5.1 percent of children born in the month immediately afterward".

The team hopes this study will make professionals take a person's age into account, and how that affects them in social situations such as school, before they diagnose younger children with ADHD, especially since most treatments involve some form of prescription medication.

Though many agree that early diagnosis is vital to finding a proper treatment so that children with ADHD do not fall behind, it's also crucial that we figure out how to accurately diagnose each case. 

You can read the team's report in The Journal of Pediatrics.