Double-blind, placebo-controlled trial of risperidone plus topiramate in children with autistic disorder.

Background: Autism is a complex neurodevelopmental disorder that forms part of a spectrum of related disorders referred to as Autism Spectrum Disorders. The present study assessed the effects of topiramate plus risperidone in the treatment of autistic disorder.

Method: Forty children between the ages of 4 and 12 years with a DSM IV clinical diagnosis of autism who were outpatients from a specialty clinic for children were recruited. The children presented with a chief complaint of severely disruptive symptoms related to autistic disorder. Patients were randomly allocated to topiramate+risperidone (Group A) or placebo+risperidone (Group B) for an 8-week, double-blind, placebo-controlled study. The dose of risperidone was titrated up to 2 mg/day for children between 10 and 40 kg and 3 mg/day for children weighting above 40 kg. The dose of topiramate was titrated up to 200 mg/day depending on weight (100 mg/day for <30 kg and 200 mg/day for >30 kg). Patients were assessed at baseline and after 2, 4, 6 and 8 weeks after starting medication. Measure of outcome was the Aberrant Behavior Checklist-Community (ABC-C) Rating Scale.

Results: Difference between the two protocols was significant as the group that received topiramate had a greater reduction in ABC-C subscale scores for irritability, stereotypic behavior and hyperactivity/noncompliance.

Conclusion: The results suggest that the combination of topiramate with risperidone may be superior to risperidone monotherapy for children with autistic disorder. However the results need to be further confirmed by a larger randomized controlled trial.