ADHD misdiagnosed in December babies
Study finds that children born later in year given unnecessary medication more often than peers
The youngest kids in class are diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) much more often than children born at the beginning of the year, and it may be simply because they are less mature, a new study concludes.
Researchers at the University of British Columbia suggest too many youngsters are incorrectly labelled and treated with medication for the neurobiological disorder when they may just need time to catch up to peers born 11 months earlier. The study, which followed 938,000 British Columbia students ages 6 to 12 over an 11-year period, was published Monday in the Canadian Medical Association Journal.
“What’s clear is the relative age of children within their grade is having an influence on who receives the diagnosis,” said Richard Morrow, lead author and health research analyst at UBC’S department of anesthesiology, pharmacology and therapeutics.
The researchers found that children with December birthdays were 39 per cent more likely to be diagnosed with ADHD than the oldest children in their grade, born the previous January. The youngest were also 48 per cent more likely to be treated with medication. The cut-off date for entry into school is Dec. 31 in British Columbia, Ontario and other provinces. “In some cases a lack of maturity among children is being misinterpreted as symptoms of a neuro-behavioural disorder,” Morrow said. “It’s really a case of medicalizing a normal range of childhood behaviours. Some children mature at a slower rate.” In 2010, two major U.S. studies came to similar conclusions and cautioned teachers and parents against comparing children in the same grade when they can be up to almost a year apart in age. The “relative age effect” — which puts younger kids within an age cohort at a disadvantage — isn’t new. It is known to impact children’s performance in academics and sports, and was most notably explored by Malcolm Gladwell in his bestselling book The Outliers. The UBC study suggests this same phenomenon is at play when it comes to behaviour. ADHD is the most common childhood psychiatric disorder, affecting between 5 and 12 per cent of school-age children. But symptoms, which include impulsivity, inattention and hyperactivity, are also typical of kids still developing self-control and the ability to focus. Morrow says one of the potential harms of misdiagnosis is unnecessary medication. Like all drugs, Ritalin, Adderall and others used for ADHD have some risk of side effects. The study doesn’t surprise Georgina Rayner of Toronto, who has spent years advocating for students with special needs, including many with ADHD.
She frequently sees cases where a child is disruptive, and schools then recommend testing or suggest parents approach the family physician to investigate ADHD.
“I really believe it can be a classroom management problem. The behaviour is driving the diagnosis,” Rayner says.
An ADHD diagnosis must also include evidence of impairment in multiple settings and not just the classroom, says Dr. Declan Quinn, child and adolescent psychiatrist at the University of Saskatchewan.
Boys are typically treated for ADHD three times more often than girls but UBC researchers found both were affected by birth dates.