April 27 (HealthDay News) -- Children who take medication to treat attention-deficit hyperactivity disorder (ADHD) do better in elementary school than those who don't, a new study has found.
Of 594 children whose parents reported an ADHD diagnosis, those who took medication scored 2.9 points higher on standardized math tests and 5.4 points higher on reading tests than children with ADHD who were not taking medication.
Researchers used a nationally representative sample from the Childhood Longitudinal Study of children who entered kindergarten in 1998, and followed them through fifth grade.
The higher test scores were comparable with the progress expected during one-fifth of a school year for math and about one-third of a school year for reading, according to the study funded by the U.S. National Institute of Mental Health.
"It's one more important piece of evidence that states clearly that taking the medication isn't just about parents or teachers feeling better about the child or thinking he or she is more compliant," said study author Stephen P. Hinshaw, chair of the department of psychology at University of California, Berkeley. "On an objective, rigorously-designed standardized test of reading and math ability, we have evidence there are 'real world' gains in achievement."
The study is published in the May issue of Pediatrics.
About 4.4 million children in the United States, or nearly 8 percent, have been diagnosed with ADHD, according to the U.S. Centers for Disease Control and Prevention. About 56 percent of those children take medication to treat the disorder and help them focus.
Boys are more likely to be diagnosed than girls. The incidence rate for boys is 10.9 percent compared to 4.4 percent of girls, according to CDC statistics from 2003.
Symptoms of ADHD include distractibility, impulsivity, excessive daydreaming, squirming and fidgeting and difficulty finishing tasks. There are several types: one that is marked primarily by inattentiveness, one marked by hyperactivity and a combined type.
ADHD has been linked with low academic achievement, including lower math and reading scores, higher rates of special education placement and high drop-out rates.
Prior research has shown the benefits of ADHD medications to children with the disorder, including improvements in short-term memory, performance of school-related tasks and rate of homework completion.
But this is one of the first to look at academic performance over the long term, said study author Richard Scheffler, a professor of public policy at UC Berkeley.
Dr. Jon Shaw, director of the division of child and adolescent psychiatry at the University of Miami School of Medicine, said the study confirms what many mental health professionals and parents have known for years about the benefits of ADHD medication.
"This well-designed research study substantiates what has been known clinically for many years, that children compromised by the symptoms of ADHD are handicapped in their school experiences and academic performance," Shaw said. "Judicious use of appropriate medications for this neurobiological condition helps these children to be successful in school and in the academic arena."
Although medications have been shown to help children with ADHD, the extensive use of drugs has been controversial, with some claiming children are being medicated unnecessarily.
The study is not advocating that every child who has attention problems be put on medication, Hinshaw said. An ADHD diagnosis should only be made after a careful evaluation by doctors.
And not all children will see test scores rise as a result of medication.
"This doesn't mean every single child will show that benefit," Hinshaw said. "Some will show more, some less. The family and clinician have to evaluate carefully the trade-off between the potential benefits and potential side effects."
While the ADHD medications improved scores, children with ADHD still had test scores that were lower on average than children without the disorder.
In addition to prescriptions, children with ADHD need active parent and teacher involvement and possible tutoring to make sure they achieve in school.
SOURCES: Stephen P. Hinshaw, Ph.D., professor and chair, Department of Psychology, University of California, Berkeley; Richard Scheffler, Ph.D., professor, public policy, University of California, Berkeley; Jon Shaw, M.D., director, Division of Child and Adolescent Psychiatry, University of Miami School of Medicine; May 2009, Pediatrics