The Impact of Attention-Deficit/Hyperactivity Disorder and Motor Deficit on Socio-Emotional Behaviors of School-Aged Children with Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is a group of developmental disorders marked by impaired social interaction and communication, restricted and repetitive behaviors. In addition to core symptoms, children with ASD often have various comorbidities, including attention-deficit/hyperactivity disorder (ADHD) and motor deficit (MD). Both the core symptoms and comorbidities of ASD have adverse effects on children’s socio-emotional behaviors that are major concerns of their parents and teachers. However, previous studies mostly focused on ASD core symptoms but rarely investigated the impact of comorbidities on children with ASD.

Objectives: The purpose of this study was to examine the influence of comorbidities, including ADHD and MD on socio-emotional behaviors of school-aged children with ASD.

Methods: Forty-four children with high-functioning ASD (8.8±1.1 years of age, 38 boys) participated in this study. ASD and ADHD diagnoses were determined by child psychiatrists. Bruininks-Oseretsky Test of Motor Proficiency, Second Edition was used to determine MD of children with a cut-off standard score of 40. Children’s socio-emotional behaviors were assessed using parental reports of the Child Behavior Checklist (CBCL). Cut-off T scores were 70 for the 8 CBCL narrow band syndromes and 63 for internalizing, externalizing, and total behavior problems. Two-way ANOVA was applied to examine the impact of ADHD and MD on socio-emotional behavior problems of children with ASD. Considering the influence of intellectual function on children with ASD, children’s intellectual ability was controlled in the analyses.

Results: Among the 44 children with ASD, 20 (45%) were also diagnosed with ADHD. Nine out of 20 (45%) children with ASD and with ADHD and 13 out of 24 (54%) children with ASD but without ADHD were found to have MD. Statistical analyses revealed that comorbidity of ADHD significantly increased attention problems (F=5.620, P=0.023), aggressive behavior (F=5.901, P=0.02), and externalizing problems (F=4.685, P=0.037) in children with ASD while comorbidity of MD only significantly increased children’s social problems (F=5.634, P=0.02). After controlling children’s intellectual quotient, however, the effect of MD on social problems in children with ASD was diminished and became borderline (F=3.979, P=0.053). No ADHD*MD interaction effect was found for socio-emotional behaviors of children with ASD.

Conclusions: Comorbidities of ASD, including ADHD and MD have further negative impact on various domains of children’s socio-emotional behaviors during school age. Medical professionals, teachers, and parents should be aware of the impact of comorbidities on functioning of children with ASD to help better plan for intervention or teaching strategies. Future research needs to consider possible influence of various comorbidities when investigating socio-emotional behaviors of children with ASD.