Positive Effects of Methylphenidate on Inattention and Hyperactivity in Pervasive Developmental Disorders: An Analysis of Secondary Measures

Background Methylphenidate has been shown elsewhere to improve hyperactivity in about half of treated children who have pervasive developmental disorders (PDD) and significant hyperactive-inattentive symptoms. We present secondary analyses to better define the scope of effects of methylphenidate on symptoms that define attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), as well as the core autistic symptom domain of repetitive behavior. Methods Sixty-six children (mean age 7.5 y) with autistic disorder, Asperger’s disorder, and PDD not otherwise specified, were randomized to varying sequences of placebo and three different doses of methylphenidate during a 4-week blinded, crossover study. Methylphenidate doses used approximated .125, .25, and .5 mg/kg per dose, twice daily, with an additional half-dose in the late afternoon. Outcome measures included the Swanson, Nolan, and Pelham Questionnaire revised for DSM-IV (ADHD and ODD scales) and the Children’s Yale-Brown Obsessive Compulsive Scales for PDD. Results Methylphenidate was associated with significant improvement that was most evident at the .25- and .5-mg/kg doses. Hyperactivity and impulsivity improved more than inattention. There were not significant effects on ODD or stereotyped and repetitive behavior. Conclusions Convergent evidence from different assessments and raters confirms methylphenidate’s efficacy in relieving ADHD symptoms in some children with PDD. Optimal dose analyses suggested significant interindividual variability in dose response.