Middle‐childhood executive functioning mediates associations between early‐childhood autism symptoms and adolescent mental health, academic and functional outcomes in autistic children

BACKGROUND: Executive functioning (EF) varies in children with autism spectrum disorder (ASD) and is associated with clinical symptoms, academic, and adaptive functioning. Here, we examined whether middle‐childhood EF mediates associations between early‐childhood autism symptoms and adolescent outcomes in children with ASD. METHODS: The Pathways in ASD Cohort comprising children recruited at the time of ASD diagnosis (at 2–4 years‐of‐age) and followed prospectively across eight subsequent timepoints over ~10 years was used. A subset of Pathways participants (n = 250) with Behavior Rating Inventory of Executive Function (BRIEF)‐Parent Form data from at least one timepoint when participants were school‐aged was analyzed. A mediation framework was used to examine whether BRIEF‐measured EF across age 7–10 years (middle‐childhood) mediated associations between early‐childhood autism symptoms (measured using the parent‐report Social Responsiveness Scale across age 2–6 years) and clinical, academic, and functional outcomes, indexed at age >10–11.8 years (early‐adolescence) using the Child Behavior Checklist (CBCL)‐Internalizing and Externalizing Scales, Academic Performance from the Teacher's Report Form, and Vineland Adaptive Behavior Scales. Models were rerun substituting clinician‐rated and teacher‐rated measures, where possible. RESULTS: Mediation models indicated a significant indirect effect of middle‐childhood EF on associations between early‐childhood autism symptoms and externalizing behavior, academic performance, or adaptive functioning in early adolescence; kappa squared (κ(2)) effect sizes ranged from large to small. Model findings were stable across raters. Middle‐childhood EF did not mediate associations between early‐childhood autism symptoms and adolescent internalizing behavior. CONCLUSIONS: Among children with an ASD diagnosis, middle‐childhood EF may be one pathway through which early‐childhood autism symptoms influence a variety of outcomes in early‐adolescence. An experimental study targeting middle‐childhood EF to improve adolescent academic, emotional/behavioral, and adaptive functioning is needed to evaluate the clinical meaningfulness of these findings.