The impact of autism and ADHD symptomology and cognitive functioning on executive functioning in autistic children

Children with ADHD, autism, and/or IDD often demonstrate EF challenges. Many children with these conditions likely demonstrate overlapping and differing EF presentations and profiles of strengths and difficulties. The extant literature investigating the impact of co-occurring ADHD and IDD on the EF of autistic children is limited and contradictory, potentially due to varying levels of symptom severity, undiagnosed co-occurring ADHD and ID, and overlapping areas of EF. Consequently, we examine how autism symptomology, ADHD symptomology, and cognitive functioning predict the EF of autistic children. Participants were 65 autistic children between the ages of 6 and 17 years and their caregivers. Multilevel modeling was used to determine the impact of ADHD symptom severity, autism symptom severity, and cognitive functioning on the EF of children with autism. Aspects of ADHD symptomology - specifically hyperactivity - and autism symptomology - namely social communication difficulties - had a significant and positive relation with EF functioning. After controlling for hyperactivity and social communication skills, there were significant differences in EF domains with emotion regulation being the most negatively impacted. The severity of ADHD and autism symptoms is positively related to EF difficulties in autistic children. Specifically, greater levels of hyperactivity and social communication difficulties predict more EF challenges. Emotion regulation appears to be the EF skill most impacted. A significant association between cognitive functioning and EF was not found in this sample.