The accident of birth has a big effect on children’s development. The circumstances of kids’ earliest years can influence their cognitive development, growth and even their wages in later life.
Now new research suggests that even the month of the year a child is born can have consequences.
In a study of over 400,000 children by the Harvard Medical School, researchers found that children born in August were more likely to be diagnosed with Attention Deficit Hyperactivity Disorder, or ADHD, than those in September.
The research, published on November 28, shows that children born in August are 30% more likely to be diagnosed with ADHD than those born in September in schools with a September 1 cutoff date for school enrollment. It’s a finding which suggests that the more boisterous behaviour of the younger children in school classes is being misdiagnosed.
“The rate of ADHD has grown considerably in the last decade,” said Professor Anupam Jena, a senior author on the study.
For the youngest children aged two to five, between 2007-8 and 2011-12 the number of diagnoses rose by over 50%. It’s led to an increase in medication: in 2016, over 5% of U.S. children were being actively treated with medication for ADHD.
But this research suggests that at least some of these cases may be misdiagnoses.
At young ages, children can show quite stark differences in behaviour from year to year. For instance, boisterous behaviour, normal for children aged six, could seem abnormal in children just a year older.
“Whenever there’s a condition, you want to be careful about whether or not to treat it with medicines”
Because of the way school year groups are arranged, children born in September can be almost a year older than their classmates born in August.
For Jena, it’s this age difference which could lead to teachers or parents unconsciously drawing comparisons between the behaviour of children of different ages.
“If you think about how diagnoses for conditions like ADHD are made, it’s very subjective,” he said. “It really relies on an assessment of how one child’s behaviour compares to all the other children that you might be seeing in any given year.”
The implication is that children may be receiving medication which they don’t need.
“Whenever there’s a condition, you want to be careful about whether or not to treat it with medicines, because there’s risks and benefits for every medicine that you give somebody,” said Jena. When the diagnoses are less secure, as the findings suggest is often the case.
While other studies have looked into ADHD diagnosis before, this is the first large scale one to analyse children across the US. It was a suspicion by one of the reports authors about their own child’s schooling which inspired the research.
“[It] started initially around a discussion by a colleague of mine, about whether or not he should hold his son back an additional year because he was young for his grade,” said Jena. Wondering whether this assumption played out in reality, the team decided to test it.
Play, and boisterousness is an important part of growing up, and, particularly when unfettered, benefits children’s cognitive development. For the younger children within age groups, this research suggests that this natural urge to play is being misdiagnosed.
For Jena, parents, teachers and school government need to begin taking children’s ages into account when they have suspicions a child may have ADHD.
“If a child is young for their age, they should probably factor that in into their assessment, and all things being equal should probably be less likely to make a diagnosis for ADHD than they would otherwise,” he said. — Anoush Darabi
(Picture credit: Flickr/Paul Hart)