One in five children identified as having attention deficit hyperactivity disorder (ADHD) may be misdiagnosed simply because they are the youngest in their kindergarten class, a recent study suggests.
Younger children are also more likely to be prescribed stimulants such as Ritalin, said Todd Elder, a researcher at Michigan State University.
"If a child is behaving poorly, if he’s inattentive, if he can’t sit still, it may simply be because he’s five and the other kids are six," Elder, an assistant professor, said in a news release.
"There’s a big difference between a five-year-old and a six-year-old, and teachers and medical practitioners need to take that into account when evaluating whether children have ADHD."
Vancouver’s Karen Elkins was surprised when her son’s Grade 1 teacher told her she suspected he had attention deficit disorder, which is similar to ADHD.
"He didn’t display any of those behaviours at home," Elkins said in an interview.
Although a psychologist said Elkins’ son was gifted, she decided to try Ritalin to see if it helped.
"I saw that he was a zombie and it took his joy away," Elkins said, adding that she believes many kids with vision or hearing problems are misdiagnosed with ADD and ADHD.
A B.C. educator who specializes in mentoring boys for success in school said he’s not surprised by the research.
"There is no blood test for ADHD – it’s very subjective and this study makes that very clear," said Barry MacDonald, author of Boy Smarts. "I’ve long suspected that our attitude toward rambunctious behaviour influences whether we perceive that children have ADHD."
The consensus is that four times as many boys as girls are diagnosed with ADHD, said MacDonald, who founded MentoringBoys.com.
The higher rate may be correlated with the fact that, generally speaking, boys are slower to develop than girls, MacDonald said.
In B.C., Dec. 31 is the cut-off date for entrance into kindergarten, so kids born earlier in the year are older than five when they enter school, while kids born in the fall are still just four years old on their first day of school.
The province introduced full-day kindergarten this month for half of B.C.’s five-year-olds with full implementation set for 2011. Patti Bacchus, Vancouver school board chairwoman, said it’s crucial that classrooms accommodate a wide range of maturity.
"That’s the one concern with all-day kindergarten – it has to be play-based and it can’t be about rushing kids into academic work and putting pressure and expectations on them," Bacchus said. "Kindergarten should be that very gentle introduction to school. It should be a very supportive and flexible environment. Kids are developing so quickly at that stage."
Using a sample of nearly 12,000 children, Elder examined the difference in ADHD diagnosis and medication rates between the youngest and oldest children in a grade. According to the study’s findings, the youngest kindergarten students were 60 per cent more likely to be diagnosed with ADHD than the oldest children in the same grade. Similarly, when that group of classmates reached the fifth and eighth grades, the youngest were more than twice as likely to be prescribed stimulants.
The B.C. Ministry of Education lists various symptoms, which, if sustained over at least six months in different settings, could be signs of ADHD. They include failure to: pay close attention to details; sustain attention in tasks or play; listen when spoken to; follow through on instructions; finish chores; and engage in tasks that require sustained mental effort. ADHD children are also forgetful and easily distracted.
The Elder study will appear in a coming issue of the Journal of Health Economics.