A research team led by Grazia Maria Giovanna Pastorino of Magna Graecia University of Catanzaro, working with colleagues at the University of Salerno and the University of Messina, recruited 123 children aged 6 to 11 years across two Italian public healthcare centers between 2021 and 2025. The sample comprised 42 children with Autism Spectrum Disorder Level 1, meaning autism without intellectual disability, 43 children with the combined presentation of Attention-Deficit/Hyperactivity Disorder, and 38 typically developing controls matched for age, sex, and socioeconomic status. Diagnoses were validated with gold-standard instruments: the ADOS-2 and ADI-R for autism, and Conners-3 parent and teacher rating scales for ADHD. Children with both conditions were deliberately excluded to isolate what the researchers call pure clinical phenotypes.

The central question was deceptively simple. Executive functions, the top-down regulatory processes of response inhibition, working memory, planning, cognitive flexibility, and attentional control, are known to support social cognition, the capacity to process and respond to socially relevant cues. Social cognition includes affect recognition, the perceptual decoding of emotional expressions, and theory of mind, the ability to attribute beliefs, intentions, and emotions to oneself and others. But it has remained unclear whether the social difficulties seen in autism and ADHD arise from shared executive failures or from disorder-specific neurocognitive wiring. Developmental models propose that executive functions provide the cognitive scaffolding on which theory of mind is built, yet the strength and shape of that scaffolding may differ dramatically across diagnostic profiles.

To find out, the team combined three standardized instruments. The WISC-IV measured cognitive functioning across verbal comprehension, perceptual reasoning, working memory, and processing speed. The BRIEF-2, completed by parents, captured everyday executive behavior at home, with higher T-scores indicating greater dysfunction. Selected NEPSY-II subtests probed performance directly, including Affect Recognition and Theory of Mind for social cognition, and Inhibition, Auditory Attention, Visual Attention, Response Set, and Design Fluency for executive functions. Testing sessions lasted roughly 90 to 120 minutes per child, and all analyses used non-parametric statistics with Bonferroni-corrected post-hoc comparisons, followed by multiple linear regression models within each clinical group.

The comparative results revealed a striking double dissociation. Both clinical groups showed widespread executive and social-cognitive impairments relative to typically developing peers, but their profiles diverged in opposite directions. Children with ADHD performed worst on response inhibition and basic attentional control, scoring significantly below the autism group on the NEPSY-II Inhibition, Visual Attention, and Auditory Attention subtests, and on the BRIEF-2 Inhibit scale, where the ADHD group’s deficit reached a large effect size. Children with autism Level 1, by contrast, showed the deepest impairments in social cognition itself, with Theory of Mind and Affect Recognition scores significantly lower than in ADHD, alongside greater difficulties in cognitive flexibility on the Response Set and Design Fluency tasks and more everyday inflexibility on the BRIEF-2 Shift scale.

Not everything separated the groups. Working memory emerged as a shared endophenotype: both clinical cohorts scored significantly lower than controls on the WISC-IV Working Memory Index, with no significant difference between them, while verbal comprehension, perceptual reasoning, and processing speed remained statistically homogeneous across all three groups. This pattern suggests that some cognitive vulnerabilities cut across traditional diagnostic boundaries, consistent with transdiagnostic models of neurodevelopmental psychopathology, even as other domains remain profile-specific.

The regression models delivered the study’s most consequential insight. In the ADHD group, theory of mind performance was strongly scaffolded by executive functions: a model combining Inhibition, Auditory Attention, and Design Fluency explained 72.2 percent of the variance in theory of mind scores. Affect recognition in ADHD was similarly driven by Inhibition and Visual Attention, accounting for 60.7 percent of variance, with theory of mind notably absent as a predictor. The interpretation is that children with ADHD do not lack social competence per se; rather, their social-cognitive performance collapses under executive load. To solve a theory of mind task, a child with ADHD must sustain attention on the narrative, inhibit premature responses, and flexibly generate solutions, and it is precisely these regulatory resources that are compromised.

In the autism group, the architecture looked fundamentally different. Theory of mind was predicted primarily by Affect Recognition and Response Set, explaining 55.1 percent of variance, with basic inhibitory and attentional resources exerting no direct predictive role. Affect recognition, in turn, was best predicted by theory of mind itself, explaining 32.7 percent of variance, suggesting an intimate interconnection between bottom-up perceptual decoding of faces and top-down mentalizing within the autistic socio-cognitive core. The authors read this as evidence that the social deficit in autism without intellectual disability is primary and pervasive, not merely a downstream consequence of generic executive failure, though it depends on higher-order flexibility and rule monitoring rather than on basic inhibition.

The clinical implications are substantial. If social difficulties in ADHD stem from executive-regulatory deficits while those in autism reflect primary mentalizing and shifting impairments, then rehabilitation cannot be one-size-fits-all. Interventions targeting inhibition and attentional control may unlock social-cognitive gains in ADHD, whereas autism-focused programs must address emotion decoding, perspective taking, and cognitive flexibility directly. The findings support transdiagnostic profiling that enriches categorical diagnoses with fine-grained cognitive mapping, potentially improving early screening during the 6-to-11 window, which the authors identify as a critical period of asynchronous maturation for both executive control and social reasoning.

The study has limitations the authors acknowledge candidly. The cross-sectional design cannot establish causal direction or track how these architectures remodel across adolescence. Excluding comorbid cases, while essential for isolating pure profiles, reduces ecological validity in a clinical world where autism and ADHD frequently co-occur. Parent-report measures on the BRIEF-2 may be shaped by informant perception and family context, and the sample, drawn from two southern Italian centers over five years, limits generalizability across cultures and to other phenotypic variants such as the predominantly inattentive presentation of ADHD. Future work, the team proposes, should add a comorbid ASD-plus-ADHD group to test whether co-occurrence produces additive, synergistic, or entirely novel endophenotypes, and should integrate eye-tracking and functional neuroimaging to quantify the visual strategies, diminished fixation on the eye region in autism, chaotic impulsive scanning in ADHD, that may underlie the distinct profiles revealed here.

Subject of Research: Neuroscience

Article Title: Neurocognitive endophenotypes in neurodevelopmental disorders: social cognition and executive functions in children with Autism Spectrum Disorder Level 1 and Attention-Deficit/Hyperactivity Disorder

Article References: Pastorino, G. M. G., Olivieri, M., Aquino, A., Mungo, N., Suriano, R., & Operto, F. F. (2026). Neurocognitive endophenotypes in neurodevelopmental disorders: social cognition and executive functions in children with Autism Spectrum Disorder Level 1 and Attention-Deficit/Hyperactivity Disorder. Frontiers in Child and Adolescent Psychiatry, 5, Article 1920753. https://doi.org/10.3389/frcha.2026.1920753

Image Credits: AI Generated

DOI: 10.3389/frcha.2026.1920753

Keywords: autism, ADHD, executive functions, social cognition, theory of mind, neurodevelopmental disorders, working memory, neuropsychology, Neurocognitive, endophenotypes, neurodevelopmental, disorders