Attention deficit disorder and methylphenidate: normalization rates, clinical effectiveness, and response prediction in 76 children.

Objective: To evaluate the magnitude and clinical significance of methylphenidate (MPH) effects on the classroom behavior and academic performance of 76 children with attention deficit disorder/hyperactivity (ADDH).

Method: A double-blind, placebo controlled, within-subject (crossover) experimental design was used to evaluate acute MPH effects at four dose levels (5 mg, 10 mg, 15 mg, and 20 mg) on children's attention, academic functioning, and behavior in regular classroom settings. Results were contrasted with a normal control sample.

Results: Standard statistical analysis revealed MPH effects on classroom functioning that were primarily linear. Analysis of the clinical significance of effects indicated that large proportions of treated children exhibited significantly improved or normalized classroom functioning; however, a large subset of them failed to show improved academic functioning. Overall, children failing to respond at lower dose levels have a high probability of improving or becoming normalized as a function of increasing dose.

Conclusions: For a majority of children with ADDH, MPH results in significantly improved or normalized attention and classroom behavior. A significant subset, however, fail to realize gains in their academic functioning and will require supplemental interventions.