Dosage effects of methylphenidate on the social behavior of adolescents diagnosed with attention deficit hyperactivity disorder.

Abstract

Research participants were 46 adolescents (mean age = 13.8 years) who completed an intensive summer treatment program including a placebo-controlled, double-blind, crossover trial of 3 doses of methylphenidate (MPH) totaling 25, 50, or 75 mg per day. Dependent measures focused on social behavior and included observed behavior frequencies and ratings completed by counselors and parents, including side effects. Multiple data analytic methods were used with the goal of (a) describing the shape of the dose-response curves across multiple measures of social functioning, (b) determining the percentage of adolescents whose social behavior improved in response to MPH, and (c) assessing the incremental gains that result from increases in dose. The results show that (a) the shape of the dose-response curve is influenced by the measurement method, (b) the majority of adolescents exhibited improved social behavior when treated with MPH, (c) the bulk of the positive effects of MPH were achieved at the lowest dose, and (d) there appear to be diminishing positive effects and an increased risk of negative effects with successively higher doses.