A developmental dose-response analysis of the effects of methylphenidate on the peer interactions of attention deficit disordered boys.

Mixed dyads of 42 normal and 42 ADD boys were videotaped in free play, co-operative task, and simulated classrooms. ADD boys received placebo, 0.15 mg/kg, and 0.50 mg/kg of methylphenidate. ADD boys were more active and off task, watched peers less, and scored lower on mathematics and visual-motor tasks. Older boys interacted less, ignored peer interactions and play more frequently, were less controlling, and more compliant. In class, methylphenidate improved visual motor scores, and reduced the controlling behaviour, activity level, and off task behaviour of ADD boys. Normal peers displayed reciprocal reductions in controlling behaviour, activity level, and off task behaviour.