Objective: To evaluate the hypothesis that gross body mass is functionally related to methylphenidate (MPH) response in children with attention deficit disorder/hyperactivity disorder (ADDH).
Method: Seventy-six children with ADDH received each of five counterbalanced doses of MPH (placebo, 5 mg, 10 mg, 15 mg, 20 mg) in the context of a double-blind, placebo-controlled, within-subject (crossover) experimental design. Dependent measures included direct observations of attention, academic efficiency, and teacher ratings of behavior in the classroom.
Results: Dose-response profiles did not differ across children varying incrementally in body mass, nor were systematic variations in dose-response curve parameters observed across discrete groups of children differing in mean body mass. Neither did these groups differ with respect to gains from placebo at each dose. Finally, body mass failed to predict optimal dose or gains achieved at optimal dose and did not distinguish between drug responders and nonresponders.
Conclusions: Collectively, the findings fail to support the practice of titrating MPH on the basis of body weight in children with ADDH.