Differential effects of stimulant medication on reading performance of boys with hyperactivity with and without conduct disorder

Abstract

Controversy surrounding stimulant medication, particularly its effects on reading performance, continues to obscure the issue of the use of this drug in classroom situations. The present study emphasized careful differential diagnosis, double-blind and placebo approaches, and curriculum-based dependent measures to address these concerns. Methylphenidate was administered to two groups of boys, ages 8 through 11. The two groups included 27 subjects meeting criteria for attention deficit-hyperactivity disorder but not conduct disorder, known as hyperactive disorder (HD), and 28 subjects meeting criteria for both diagnostic categories, known as hyperactive-aggressive (HA). Only four subjects in each group met a discrepancy criterion for learning disabilities (LD). Methylphenidate was administered to both groups at three levels of dosage, along with baseline and placebo conditions. Dependent measures involved both reading recognition and reading comprehension, equivalent across all conditions. No significant results were found for the group with HD in either reading recognition or comprehension, due largely to unusual placebo reactions. Results were generally in the direction predicted for the group with HA, but only significantly so in reading comprehension, and no dose effect was found on this variable. Implications for reading as a dependent measure of medication effects are discussed.