Effects of methylphenidate on behavioral adjustment in children with mental retardation and ADHD: Preliminary findings from a study in progress

In this preliminary report from a study in progress, the effects of methylphenidate on behavioral adjustment in children (N = 13) with mental retardation (MR) and Attention Deficit Hyperactivity Disorder (ADHD) were investigated using a placebo-controlled double blind, crossover design. Parent and teacher behavioral ratings, and reports of side effects, were obtained with placebo 0.15 mg/kg, 0.30 mg/kg, and 0.60 mg/kg BID dosages of methylphenidate. Results revealed significant declines in ADHD symptomatology (e.g., inattention, hyperactivity) with medication treatment, with the most significant declines appearing at the 0.60 mg/kg dose of the medication. No significant behavioral improvements (relative to placebo) were noted below the 0.60 mg/kg threshold, i.e., at the 0.15 mg/kg or 0.30 mg/kg dosages. These preliminary results strongly suggest that teachers may be more sensitive raters of symptoms of ADHD, or else may simply have more opportunity to observe the core symptoms of ADHD in a setting in which such symptoms are most likely to be problematic. Although teachers appeared to be more sensitive raters of ADHD symptomatology, parents may have been more sensitive raters of symptoms of side effects than were teachers. Results suggest that both parents and teachers provide important information in titrating stimulant medication in children with MR and ADHD.