Effects and noneffects of methylphenidate in children with mental retardation and ADHD.

Stimulant medication efficacy was evaluated in 14 children with attention-deficit hyperactivity disorder and IQs of 48 to 74 in a double-blind crossover study of two methylphenidate doses and placebo. Dependent measures included behavioral ratings, work output, measures of learning, attention and impulsivity, and direct observation of peer social interactions. Nine children (64%) were methylphenidate-responders, based upon the Conners Hyperactivity Index. Significant gains in on-task behavior and attentional skills were noted with methylphenidate in comparison to placebo. No improvement on measures of learning or social interactions were observed. Results extend and replicate previous research conducted by the authors.