Timing of Stimulant Treatment for ADHD and Effect on Academic Progress
Pediatric Neurology Briefs
and other centers in Iceland and in USA studied the probability of academic decline (drop of >5.0 percentile points) in ADHD children according to drug exposure and timing of treatment start between National Scholastic Examinations. Medications recorded for each person with ADHD in the Icelandic Medicines Registry included amphetamine, methylphenidate, and atomoxetine; the majority (96%) were treated with methylphenidate in extended-release formulation. Of 13,617 children registered in the
... istered in the Icelandic school system, 11,872 took standardized tests, and 1029 (8%) were treated with ADHD drugs at any time during the study period. Medicated children scored lower on their fourth-grade tests (taken before their start of treatment) than the nonmedicated general population. Those children starting treatment between their fourth (age 9) and seventh-grade (age 12) tests were more likely to decline in test performance, in contrast with nonmedicated children. The mean decline was 9.4 percentile points in mathematics for those with delayed treatment initiation. The probability of academic decline was 72.9% in mathematics and 42.9% in language arts for children who started treatment 25 to 36 months after the fourth-grade test. Compared to those starting treatment earlier (<12 months after tests) the risk ratio (RR) for decline was 1.7 (1.2-2.4) in mathematics and 1.1 (0.7-1.8) in language arts. The adjusted RR of mathematics decline with later treatment was higher among girls (RR 2.7; [1.2-6.0]) than boys (RR 1.4 [0.9-2.0]). (Zoega H, Rothman KJ, Huybrechts KF, et al. A populationbased study of stimulant drug treatment of ADHD and academic progress in children.