Symptomatic Predictors of Adaptive Functioning in Children with ASD

Background: Research has consistently shown that children with Autism Spectrum Disorders (ASD) exhibit adaptive skills that are substantially lower than would be expected on the basis of their intellectual functioning. ASD symptomatology has potential to account for this finding. However, the specific relationship between adaptive functioning and ASD symptomatology remains unclear.

Objectives: To examine if ASD symptomatology, as measured by the Autism Diagnostic Interview-Revised (ADI-R), predicts adaptive functioning, as measured by the Vineland-II, in children with ASD.

Methods: Data were obtained through retrospective file review from routine clinical practice over a three-year period at a university-based clinic specializing in assessment and diagnosis of children with ASD. All children (N=38), age 3-7, were diagnosed with an ASD and administered the ADI-R, the Vineland-II, and a standardized measure of cognitive functioning.  Separate hierarchical multiple regression analyses were conducted to determine if the ADI-R current algorithm items in the Communication and Socialization domains uniquely predicted the Communication and Socialization domains of the Vineland-II.  Composite non-verbal cognitive scores were entered in the first step of the regression for both analyses.

Results: For the communication analysis, cognitive scores explained 44.4% of variance in the Vineland-II Communication score.  After entry of the ADI-R Verbal Communication score at Step 2, the total variance explained by the model as a whole was 44.7%, F (2, 31) = 10.10, p < .01. In the final model, only cognitive scores significantly predicted communicative adaptive scores.  For the socialization analysis, cognitive scores explained 15.1% of variance in the Vineland-II Socialization score.  After entry of the ADI-R Socialization score at Step 2, the total variance explained by the model as a whole was 27.1%, F (2, 31) = 5.75, p < .01. The ADI-R Socialization score explained an additional 11.9% of the variance in the Vineland-II Socialization score, after controlling for cognitive functioning, R² change = .119, F change (1, 31) = 5.08, p < .01.  In the final model, both cognitive scores and ADI-R Socialization symptoms uniquely predicted Vineland-II Socialization scores.

Conclusions: These results suggest that ASD Socialization symptoms uniquely predict social adaptive functioning, while ASD Communication symptoms do not predict communicative adaptive functioning.  This finding is relevant to intervention efforts where a major effort is made to reduce symptoms with the goal of maximizing positive outcomes.  It is of note that the non-verbal cognitive composite score accounted for a significant portion of variance in both the Vineland-II Communication and Socialization domains.  This stresses the importance of considering the child's cognitive abilities when considering their adaptive functioning strengths and weaknesses. Future research examining how cognitive functioning and specific domains of ASD symptomatology influence the development of adaptive functioning in individuals with ASD will assist in designing individualized interventions.