(NEW YORK) -- Children with attention deficit hyperactivity disorder (ADHD) who start taking medications as early as fourth grade may be more likely to score better academically than those who start taking medication in middle school, according to a study published Monday in the journal Pediatrics.
ADHD is a developmental disorder characterized by problems focusing and erratic behavior. Since 2007, 5.4 million children ages 4 to 17 have been diagnosed with ADHD, and 66 percent reported taking medication to treat their symptoms, according to the U.S. Centers for Disease Control and Prevention. A majority of children are diagnosed with ADHD by age 7.
Researchers looked at data of nearly 12,000 Icelandic children born between 1994 and 1996, each of whom began taking medication for ADHD sometime between fourth and seventh grades. By the time the children reached seventh grade, those who had begun taking medications within the first year of fourth grade showed only a 0.3 percent drop in their math score, compared to a 9 percent drop among children who started medication around sixth or seventh grade.
"Performance of kids with ADHD tends to decline over time, especially if medication is delayed," said Helga Zoega, an epidemiologist at the Institute for Translational Epidemiology at Mount Sinai School of Medicine in New York, and lead author of the study. "Starting medication earlier may halt this decline."
The girls among the group only showed improvement in math after starting medication. The boys showed improvement in both math and language arts.
A majority of kids are diagnosed with ADHD by age 7, Zoega said.
Besides medication, treatments for ADHD include behavioral interventions, education plans and parental training. The interventions may be the first line of treatment before medication, or may be used in combination with medication.
The study data did not show whether the children received other forms of treatment besides medication, and whether these additional treatments may have influenced their performance.
Copyright 2012 ABC News Radio