C-65 Transdiagnostic Factors of Social Impairment in Comorbid Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder

Objective Comorbid Autism Spectrum Disorder (ASD) and ADHD are associated with greater symptom severity, including social impairment. Furthering work by Lerner, Pothoff, and Hunter (2015), we sought to identify unique and shared factors that contribute to parent-reported social deficits in children with ADHD, ASD, and ADHD+ASD. We hypothesized attention, hyperactivity, and motor skills would predict social deficits in ADHD, while functional communication and motor skills would predict social deficits in ASD; and additively, all factors would predict social deficits in ADHD+ASD. Method Utilizing a clinical database, we identified 236 participants (4-21 years; Mage = 10.6; 71% male; 28% African American; FSIQ M = 94.31) with diagnoses of ADHD, ASD, and ADHD+ASD. We examined FSIQ from the WISC-4/5, WPPSI-3, or DAS-2, motor skills and social impairment from the SIB-R and attention, hyperactivity, and functional communication from the BASC-2/3. Results Using hierarchical linear regression and controlling for FSIQ, hypotheses were partially supported. FSIQ was controlled for in each group. For ADHD, hyperactivity, functional communication, and motor skills contributed significantly to the model (p < .001), while for ASD, motor skills contributed significantly to the model (p < .001). For ASD + ADHD, functional communication and motor skills contributed significantly to the model (p < .001) Conclusion Results support previous findings that motor deficits and functional communication are associated with social impairment in children with ADHD and ASD, independently and comorbidly. This suggests that targeting motor dysfunction and functional communication concurrently may be effective for improving social interaction skills in children with ADHD +ASD.