Our study compared oppositional defiant disorder (ODD) in children with autism to ADHD-Combined presentation and ADHD-Inattentive presentation. Mothers of 2,400 children 3-17 years old with autism and/or ADHD completed the Pediatric Behavior Scale. ADHD-Combined was most strongly associated with ODD, with an ODD prevalence of 53% in children with ADHD-Combined only. When autism was added to ADHD-Combined, prevalence increased to 62% and the ODD score increased significantly….
