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.