Double-Blind, Placebo-Controlled Trial of Risperidone Plus Amantadine in Children With Autism: A 10-Week Randomized Study

Objective: This study aimed to investigate the effect of adding amantadine to risperidone for treatment of autism. Methods: Forty outpatients aged 4 to 12 years, who were diagnosed with autism spectrum disorders based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria, were assigned to this double-blind clinical trial. The subjects were divided randomly into 2 groups. One group received risperidone plus amantadine, and the other group received risperidone plus placebo. The dose of risperidone was titrated between 1 and 2.0 mg/d, and the dose of amantadine was 100 or 150 mg/d for patients less than 30 kg or more than 30 kg, respectively. The patients were assessed using the Aberrant Behavioral Checklist-Community (ABC-C) and adverse effects checklist as well as clinical global impression-improvement (CGI-I) at 2 checkpoints of 5-week intervals after the baseline. Informed consent was obtained from the parents of each participant. Results: Among ABC-C subscales, Hyperactivity and Irritability showed significantly greater reduction in the amantadine group than the placebo group. There was no significant difference in adverse effects between the 2 groups. The CGI-I scores show significant improvement in the amantadine group compared to the placebo group. Conclusions: The present study suggests that amantadine may be a potential adjunctive treatment strategy for autism and it was generally well tolerated.