Improved Executive Function over Time in Children with ASD and Relations with Mental Health and Functional Outcomes
Objectives: We aimed to examine: 1) how EF skills change over time in a large longitudinal sample of children with ASD followed across school age; and (2) whether EF skills in school-age predict functional outcomes in pre-adolescence.
Methods: Our sample included data from 202 children prospectively followed in a large Canadian multisite longitudinal study (Pathways in ASD Study) from the time of clinical diagnosis of ASD in early childhood (2-4 years of age, T1) across 7 additional timepoints (T2-7). Data collected when children were age 6 (T4), and every 1-2.5 years thereafter (T5-8) was used (sample age=10-11.8 years at T8). The Behavior Rating Inventory of Executive Function(BRIEF) Behavioral Regulation (BRI) and Metacognitive Index (MCI) Subscales (T5-8), Vineland Adaptive Behavior Scale(VABS) Adaptive Behavior Composite Score (T8), Child Behavior Checklist(CBCL) Internalizing/Externalizing Scores (T8), teacher-report of academic performance (Teacher Report Form) (T8), and Wechsler Preschool and Primary Scale of Intelligence-measured full scale IQ (T4) were used. Repeated measures analysis was used to examine change in BRI and MCI T scores collected in participants across school-age (T5-8). Hierarchical regressions were used to examine whether BRI and MCI scores (collected at T5-7) predicted VABS composite, CBCL internalizing/externalizing and academic performance scores at T8 (N=71-88). FSIQ was entered in the first step for each model to control for effects of general intelligence.
Results: Repeated measures analysis showed a significant decline for both BRI (F3, 279= 4.88, p = .003) and MCI T-scores (F3, 250= 5.56, p = .001) across T5 to 8. Hierarchical regressions indicated that: BRI predicted both internalizing (β=.46, p<0.01) and externalizing (β=.37, p<0.01) behaviours in models controlling for MCI, FSIQ and internalizing or externalizing behaviours; and BRI (β=-.37, p<0.01), MCI (β=.17, p<0.05), and FSIQ (β=.26, p<0.01) were all significant predictors of academic performance. Only FSIQ was a significant predictor of VABS composite scores.
Conclusions: Our preliminary findings indicate that in children with ASD, EF skills improve across school age. Parent-reported EF skills collected across school age are also predictive of parent-reported mental health symptoms, and teacher-reported academic performance in the same children in pre-adolescence. EF skills may be an important cognitive domain to track in children with ASD as well as a novel treatment target with the potential for positive downstream effects on academic performance and mental health symptoms.