School Age Cut-Offs and ADHD: What's the Connection?

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After finding out she was due sometime in early November, Julie Graves of Ann Arbor, Michigan, remembers quickly looking up the kindergarten age cut-off for her local school district.

"I breathed a sigh of relief when I saw it was December 1," Graves explains. "In my mind, this meant that my son 'wouldn't need to wait' like I did with an October birthday, growing up in a state where the cut-off was September 1."

What Graves didn't really stop to consider then—or over the next five years—was what being among the youngest in class might mean for her son.

When she volunteered in her son's class about halfway through his kindergarten year, however, she was immediately struck by the age gap. "It was January and one of his classmates was turning 6 that day. This little girl read a birthday card from the class with such confidence that I couldn't help but compare her to my son, who still looked and acted like a preschooler. I became instantly worried that I had made a horrible mistake by enrolling him just because he squeaked by the age cutoff," admits Graves.

Was she right to be concerned? According to education and child development experts, in the early elementary years (and younger), age spreads of even of a few months may mean significant differences in language ability, social skills, and maturity levels between children in the same grade level.

But there is potentially a new wrinkle for parents to take into account when it comes to school age cut-offs—and it's a big one. According to a study published recently in the journal Pediatrics, school age children in the youngest third of their class are 50 percent more likely than their older peers to be prescribed ADHD drugs.

The study, conducted in Iceland where there's been a fierce debate over the diagnosis of attention deficit hyperactivity disorder—ADHD—and the use of stimulants to treat it, tracked nearly 12,000 children born between 1994 and 1996. Researchers looked at children's standardized test scores at ages 9 and 12, and examined whether they were prescribed drugs for ADHD.

Overall, 740 children—about 6 percent of the total—were prescribed ADHD drugs at some point from 2003 to 2009. However, children in the youngest third of their classes were 50 percent more likely than those in the oldest third to be prescribed ADHD medications from ages 7 to 14. The study also found that younger children scored lower on standardized tests.

Are the statistics just an anomaly? It doesn't seem to be the case since previous research, conducted in Canada, found the same correlation between age and ADHD diagnoses. According to a study in the Canadian Medical Association Journal that examined medical records from nearly one million 6- to 12-year-olds in British Columbia, where incoming kindergarten students need to turn five by Dec. 31, boys born in December were 30 percent more likely to receive an ADHD diagnosis than boys born in January (who are 11 months older). Likewise, December-born girls were 70 percent more likely to get the diagnosis, though boys still make up the bulk of children diagnosed with the disorder.

What does all this mean? Graves says she's now on guard. "If I ever have a teacher or counselor at school float the idea of ADHD, I would demand my son be tested in such a way that the standard he is held to is what's appropriate for his precise age, not some kind of grade level assessment."

A researcher involved with this most recent study, Helga Zoega, a postdoctoral fellow at Mount Sinai School of Medicine in New York City, seems to agree. "Educators and health-care providers should take children's ages in relation to their [classmates] into account when evaluating academic performance and other criteria for ADHD diagnosis," she tells HealthDay. "Parents can use these findings to help inform their decisions about school readiness for children born close to cutoff dates for school entry."

But what does this mean for parents going back and forth over whether to have their child start kindergarten now or wait another year? There's simply no easy answer. Some parents may choose to delay kindergarten if their child's birthday falls too close to the cutoff point as a way to give them an academic and social advantage, but this doesn't work for all families, and it's not practical for all children. Plus, it doesn't solve the problem that there will always be kids who are the youngest in their class.

Instead, it may be time to look at whether schools are set up to truly help all children succeed, regardless of age. As Richard Morrow, a health research analyst at the University of British Columbia who studies ADHD, tells HealthDay, "In the education system, it leads to the question, 'What strategies or resources do we need to help ensure the well-being of all children in the classroom, where children vary in age by up to a year?'"

"Parents need to be aware that if behavioral issues arise for their child, this may be related to their child's relative age in the classroom."