ROCHESTER, Minn. -- In an 18-year-study on attention-deficit hyperactivity disorder (ADHD), Mayo Clinic researchers found that treatment with prescription stimulants is associated with improved long-term academic success of children with ADHD. The Mayo Clinic results are the first population-based data to show stimulant drug therapy helps improve long-term school outcomes.
A related Mayo Clinic study reveals that compared to children without AD/HD, children with ADHD are at risk for poor long-term school outcomes such as low achievement in reading, absenteeism, repeating a grade, and dropping out of school. Both studies appear in the current edition of the Journal of Development & Behavioral Pediatrics, (http://www.
Nearly 2 million children, or approximately 3 percent to 5 percent of young children in the United States, have ADHD. This disorder affects a child's ability to focus, concentrate and control impulsive behavior (http://www.
"In this study, treatment with stimulant medication during childhood was associated with more favorable long-term school outcomes," explains William Barbaresi, M.D., Mayo Clinic pediatrician and lead author of the reports.
Significance of the Mayo Clinic Studies
The two Mayo Clinic studies are the first population-based, long-term studies to investigate links between ADHD, school performance and factors that modify long-term school performance of children with ADHD. Researchers followed the children from the time they were born for, on average, 18 years. Of the more than 5,000 children evaluated, 370 (277 boys and 93 girls) were identified as having ADHD. Researchers matched them by age and gender to 740 children who did not meet the research criteria for having AD/HD. In addition to medical stimulants such as methylphenidate, also called Ritalin, the study examined the effects on school outcomes of maternal age, socioeconomic background, and special education services the students received.
School Outcome Results At a Glance
The children treated with stimulants typically began taking medication in elementary school and received it for nearly three years -- on average, for 30.4 months. Results indicate:
- Gender: Girls and boys with untreated ADHD were equally vulnerable to poor school outcomes -- and girls may be at risk for being under-identified as having ADHD, and therefore undertreated.
- Reading: By age 13, on average, stimulant dose was modestly correlated with improved reading achievement scores.
- Absenteeism: Both treatment with stimulants and longer duration of medication were associated with decreased absenteeism.
- Grade Retention: Children with A/HD who were treated with stimulants were 1.8 times less likely to be retained a grade than children with ADHD who were not treated.
Implications for Parents and Caregivers
Dr. Barbaresi believes that both studies provide the first solid evidence of the long-term negative academic performance associated with untreated ADHD -- as well as evidence for the best way to manage this problem. Dr. Barbaresi says, "The finding that treatment with stimulant medications is associated with long-term improvement in school outcomes is significant. Previously, there was evidence that treatment with stimulant medications improved short-term academic performance, but there was no good evidence that long-term outcomes are better with stimulant treatment. Our data can guide clinicians in their efforts to help children with ADHD succeed in school."
About the Studies
The Mayo Clinic team had a unique ability to identify groups of children with and without ADHD. Mayo Clinic has maintained a comprehensive communitywide medical records database since 1935, and researchers had access to all conditions, diagnoses and treatments the children received. In addition, Mayo obtained a research agreement with Independent School District #535, Rochester, Minn., including public and private schools, to access non-identifiable school records of all children born in Rochester between Jan. 1, 1976 and Dec. 31, 1982. This enabled researchers to correlate school performance of both children with and without ADHD in terms of medical conditions, maternal age, socioeconomic status and special education efforts.
Collaboration and Support
In addition to Dr. Barbaresi, the Mayo Clinic research team also included Slavica Katusic, M.D.; Robert Colligan, Ph.D.; Amy Weaver, M.S.; and Steven Jacobsen, M.D., Ph.D. Their work was supported by grants from the U.S. Public Health Service; National Institutes of Health; McNeil Consumer and Specialty Pharmaceuticals; and Mayo Clinic Foundation for Biomedical Research.