Comparing classroom and clinic measures of attention deficit disorder: Differential, idiosyncratic, and dose-response effects of methylphenidate.

The present investigation examined the utility of clinic-based testing (CPT: Continuous Performance Test) and classroom observations in detecting dose-related behavioral changes in Attention Deficit Disorder (ADD) children. Fourteen ADD children between 6 and 10 years of age participated in a double-blind, placebo-control, within-subject (crossover) design in which each child received three doses of methylphenidate (5, 10, 15 mg) in a randomly assigned sequence. A one-way multivariate analysis of covariance with repeated measures demonstrated a highly significant effect on the six dependent measures. A series of one-way analyses of covariance with repeated measures showed significant medication effects on classroom percentage of on-task behavior, percentage of assignments complete, percentage of accurate assignments, CPT omission and commission errors, and teacher ratings of children's behavior. Trend analyses revealed a significant quadratic relationship between the primary measures of attention and dose. Fixed-dose and milligram per kilogram plots were drawn and compared for a random subset of children to illustrate the idiosyncratic and task-specific behavior exhibited across doses.