An individual double-blind crossover trial for assessing methylphenidate response in children with attention deficit disorder.

To obtain more objective data on response to therapy and to overcome parents', teachers', psychologists', and physicians' concerns about potential overuse, I instituted individual double-blind crossover trials of methylphenidate for children with attention deficit disorder (ADD). Each child is given 0.3 mg/kg/dose twice daily for 2 weeks and placebo for 2 weeks in random order and in double-blind fashion. Parents and teachers record observations of behavior and academic performance. Analysis of 70 trials and follow-up clinical data demonstrated that (1) 51 children showed improvement in one of the 2-week periods and that period corresponded with methylphenidate therapy in 48 (69%); (2) 6 of the 22 who did not respond to methylphenidate experienced worsening of function while taking the drug; (3) history and physical findings were not helpful in predicting methylphenidate response; (4) there were no serious side effects during the trial; and (5) all but three of the responders took methylphenidate for at least 1 year with sustained improvement in behavioral function, academic function, or both. Individual double-blind crossover trials can be used in an office setting to identify objectively which children with ADD respond to treatment with methylphenidate. Because the trial demonstrates to parents, teachers, psychologists, and physicians that methylphenidate is or is not beneficial to a particular child, this clinical tool is associated with a high level of confidence that the drug is being appropriately prescribed.