Investigation of the Rates of Comorbid Symptoms in Children with ADHD Compared to Children with ASD

There is a scarcity of research looking at how comorbid psychological disorders impact the assessment of children with autism spectrum disorders (ASD). The present study aimed to extend the literature in this area by evaluating rates of comorbid symptoms in both children with ASD and those with attention-deficit/hyperactivity disorder (ADHD). Children with ASD, ADHD, or no psychological diagnosis participated in this study. Internalizing and externalizing symptoms were assessed with the Autism Spectrum Disorders - Comorbidity for Children (ASD-CC). Multivariate and univariate main effect analyses with post-hoc comparisons were then conducted. Children with ASD evinced higher rates of comorbid symptoms than children with ADHD. Additionally, both children with ASD and those with ADHD exhibited more comorbid symptoms than children without a psychological disorder. These findings are in accordance with previous research and support the need for broadband assessment of psychiatric conditions in children presenting with developmental delays or externalizing behaviors. Other implications of these findings are discussed.