Being younger than one’s classmates affects academic performance as well as children’s risk of being on prescribed drugs for ADHD, according to a new study conducted in Iceland.
The study’s lead author is Helga Zoëga, assistant professor at the University of Iceland and postdoctoral researcher at Mount Sinai School of Medicine in New York.
A cohort of 11,785 children in Iceland born in 1994-1996 was used. Helga and her colleagues found that test scores in mathematics and language arts among nine-year-olds were lowest among the youngest children in the class and increased linearly with relative age.
The effect decreases over time but is still present at age 12, as reported on the website of the University of Iceland.
The study also found that the youngest third of children in the class were over 50 percent more likely to use stimulants for ADHD than the oldest third in class.
The study was conducted in collaboration with Harvard School of Public Health and was published in the journal Pediatrics on November 19.
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