A population-based study of stimulant drug treatment of ADHD and academic progress in children.

• Published in: Pediatrics
• Main Authors: Zoëga, Helga, Rothman, Kenneth J, Huybrechts, Krista F, Ólafsson, Örn, Baldursson, Gísli, Almarsdóttir, Anna B, Jónsdóttir, Sólveig, Halldórsson, Matthías, Hernández-Diaz, Sonia, Valdimarsdóttir, Unnur A
• Other Authors: Center of Public Health Sciences, Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Reykjavik, Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: Achievement; Age Factors; Amphetamine; Attention Deficit Disorder with Hyperactivity; Central Nervous System Stimulants; Child; Educational Measurement; Female; Humans; Iceland; Language Arts; Male; Mathematics; Methylphenidate; Multivariate Analysis; Odds Ratio; Propylamines; Registries; Sex Factors; Treatment Outcome
• Online Access: http://hdl.handle.net/2336/302014; https://doi.org/10.1542/peds.2011-3493

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field. We evaluated the hypothesis that later start of stimulant treatment of attention-deficit/hyperactivity disorder adversely affects academic progress in mathematics and language arts among 9- to 12-year-old children. We linked nationwide data from the Icelandic Medicines Registry and the Database of National Scholastic Examinations. The study population comprised 11,872 children born in 1994-1996 who took standardized tests in both fourth and seventh grade. We estimated the probability of academic decline (drop of ≥ 5.0 percentile points) according to drug exposure and timing of treatment start between examinations. To limit confounding by indication, we concentrated on children who started treatment either early or later, but at some point between fourth-grade and seventh-grade standardized tests. In contrast with nonmedicated children, children starting stimulant treatment between their fourth- and seventh-grade tests were more likely to decline in test performance. The crude probability of academic decline was 72.9% in mathematics and 42.9% in language arts for children with a treatment start 25 to 36 months after the fourth-grade test. Compared with those starting treatment earlier (≤ 12 months after tests), the multivariable adjusted risk ratio (RR) for decline was 1.7 (95% confidence interval [CI]: 1.2-2.4) in mathematics and 1.1 (95% CI: 0.7-1.8) in language arts. The adjusted RR of mathematics decline with later treatment was higher among girls (RR, 2.7; 95% CI: 1.2-6.0) than boys (RR, 1.4; 95% CI: 0.9-2.0). Later start of stimulant drug treatment of attention-deficit/hyperactivity disorder is associated with academic decline in mathematics Pfizer Novartis University of Iceland Icelandic Centre for Research (RANNIS)