Atomoxetine in Autism Spectrum Disorder: No Effects on Social Functioning; Some Beneficial Effects on Stereotyped Behaviors, Inappropriate Speech, and Fear of Change

Objective: The objective of this study was to investigate the short-term treatment effects of atomoxetine on autism spectrum disorder (ASD) symptoms in children and adolescents with both ASD and attention-deficit/hyperactivity disorder (ADHD). Methods: A total of 97 patients 6-17 years of age, with ASD and ADHD, were treated with 1.2 mg/kg/day of atomoxetine during an 8 week double-blind placebo-controlled period. Here, we investigated effects on two parent-based secondary outcome measures, the Aberrant Behavior Checklist (ABC) and the Children's Social Behavior Questionnaire (CSBQ). Results: After 8 weeks of double-blind treatment, atomoxetine administration was associated with significant treatment effects on the ABC subscales Hyperactivity, Inappropriate Speech, and Stereotypic Behavior, and on the CSBQ subscale Fear for Changes. Conclusions: Our study results indicate no beneficial effects of atomoxetine on social functioning. However, atomoxetine may ameliorate restricted and stereotyped behaviors and communication. This study has been registered in ClinicalTrials.gov (www.clinicaltrials.gov) under registration number NCT00380692.