The relationship of attention-deficit hyperactivity disorder and autism spectrum disorder to adaptive skills in young children

Objective: Attention-deficit hyperactivity disorder (ADHD) has been linked to deficits in socialization and communication, similar to those observed in children with ASD. In the present study, we examine the differences in developmental quotient and subscale scores between children with ASD and children with ADHD.Methods: We compared the developmental scores in a sample of 2990 children who presented to an early intervention program, who met criteria for ASD, inattentive ADHD, hyperactive/impulsive ADHD, combined ASD/ADHD, or are at risk for developmental disorders.Results: The overall developmental quotient did not significantly differ between those in the ADHD inattentive and hyperactive subtype groups. Adaptive skills differed most greatly between the ASD groups and the ADHD/atypically-developing groups.Conclusion: The present study represents a first step towards understanding the relationship of ADHD to ASD in early childhood. Young children with ASD symptoms are more greatly impaired than those with symptoms of ADHD.