Age Matters When Diagnosing ADHD

ADHD diagnosis more likely among younger classmates

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) The younger a child is, the more rambunctious they tend to be.  While this behavior is typically seen as normal, more and more younger children today are being diagnosed as ADHD as compared to their older classmates.  

This has led some to wonder if too many young children are being misdiagnosed and over-prescribed medication.

"Evaluate diagnostic method options for ADHD.  "

While there are over 5.2 million children ages 3-17 in the US diagnosed with ADHD as of 2010 according to the Centers for Disease Control and Prevention, scientists decided to focus on a younger age range to determine if children are being misdiagnosed as ADHD.  

In a group study focusing on Canadian school boys and girls ages 6-12, researchers from the Canadian Medical Association found that it is typically the youngest members of a class that are diagnosed as ADHD as well as prescribed medication for it. 

The study, which focused on the British Columbian school cut-off date of December 31, compared ADHD diagnosis among children who were born in December versus children who were born in January.

Since students have to be a certain age by the school’s enrollment date, kids who barely qualify before the deadline ends tend to be a lot younger than kids that were born earlier in the year.  They are sometimes up to a whole year younger than their classmates.

Researchers evaluated 937,943 children who were ages 6-12 any time from December 1, 1997 to November 30, 2008.  They also compared boys and girls who were born in December to boys and girls who were born in January. 

What researchers found was that boys who were born in December were 30 percent more likely to be diagnosed as ADHD and 41 percent more likely to be prescribed medication for their diagnosis than their male classmates who were born in January. 

Similarly, girls who were born in December were 70 percent more likely to be diagnosed as ADHD and 77 percent more likely to be given medication to treat it than girls who were born in January. 

This has led the Canadian researchers to believe that there is valid concern for the misdiagnosis of ADHD and over-prescription of medications among children who experience relative-age differences within their classrooms. 

Although the study focuses on the child enrollment age in Canadian school systems, US schools have similar cut off dates and experience a similar age differences among children who are in the same class. 

This study was conducted by the Canadian Medical Association and published by the Canadian Medical Association Journal in March of 2012.  No conflicts in funding were presented.

Reviewed by: 
Review Date: 
March 9, 2012
Last Updated:
October 3, 2012