Effects of methylphenidate on reading in children with attention deficit disorder.

Effects of methylphenidate on measures related to reading were studied in a group of nine boys who had attention deficit disorder with hyperactivity; a double-blind crossover design using active drug and placebo was used. Administration of methylphenidate improved subjects' performance on language processing tests but not their performance on oral reading measures. The findings provide evidence in support of a two-factor theory of attention deficit disorder.