Cognitive and emotional profiles in children with ASD, ADHD, and comorbid presentations: evidence for a distinct clinical phenotype

Background: Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) frequently co-occur, yet their comorbid presentation (ASD+ADHD) remains under- characterized. Clarifying cognitive and behavioral profiles is crucial for accurate diagnosis and effective intervention. Methods: A total of 207 children and adolescents (ages 6-16) were assessed using the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) and the Child Behavior Checklist (CBCL 6-18). Participants were grouped into ASD (n = 21), ADHD (n = 103), and ASD+ADHD (n = 83) cohorts. Group differences were analyzed through ANOVAs with Bonferroni corrections; Pearson correlations explored associations between cognitive indices and behavioral outcomes. Results: Children with ASD+ADHD scored significantly lower than the ASD group in working memory, processing speed, and full-scale IQ, while no significant differences emerged between the ASD+ADHD and ADHD groups. Behaviorally, ADHD participants exhibited higher externalizing symptoms (e.g., aggression, rule-breaking), while the ASD group showed greater withdrawn/depressed traits. The comorbid group presented the broadest dysregulation, with elevated scores across both internalizing and externalizing domains, including Sluggish Cognitive Tempo and obsessive-compulsive symptoms. Notably, protective associations between cognitive abilities and behavioral regulation, present in ASD and ADHD, were absent in the ASD+ADHD group. Conclusions: Findings suggest that ASD+ADHD comorbidity represents a distinct clinical profile, marked by compounded cognitive impairments and pervasive emotional-behavioral dysregulation. These patterns underscore the need for differential diagnostic approaches and tailored interventions that account for the unique neurocognitive architecture of comorbid presentations.