Relationship Between Adaptive Functioning and Autism Symptom Severity

Background: Communication and socialization are adaptive skills which are central for the study of individuals with autism, since impairment in these two domains are the defining features of the disorder. When compared with typically developing children, those with autism have shown greater impairment in their adaptive behavior, even when matched for age and IQ

 Objectives: The aim of the present study was to investigate the relationship between adaptive behavior and autistic symptomatology in preschool children with autism. It was predicted that there would be a correlation between autistic symptomatology and adaptive functioning, and that this relationship would be stronger in terms of socialization and communication.

 Methods: Age, adaptive skills levels, and autistic symptomatology levels were collected on consecutive participants, as a part of an epidemiological study of autism spectrum disorders at the University of Zulia’s Developmental Disorders Clinic. Participants in this study included 52 children with autism aged 3 to 6 years. Children were diagnosed using SCQ scores above 15, algorithm scores from the Autism Diagnostic Observation Schedule (ADOS); and having the diagnosis confirmed by an expert clinician; and parents were interviewed using the Spanish Vineland Adaptive Behavior Scales (VABS). All children in the study met SCQ , ADOS and clinican criteria for autism. Exclusion criteria were: known brain lesions, tuberous sclerosis, neurofibromatosis, hemiparesis, ataxia, or any “hard” neurological sign.

 Results: The socialization domain only exhibited significant correlations with the play scores (-0.565), and repetitive/stereotyped behavior (-0.485). The communication domain showed the most correlations with the autistic symptomatology; there were significant negative correlations with the ADOS social reciprocal interaction (-0.413), the sum of communication and social interaction (-0.387), play (-0.425), and repetitive/stereotyped behavior (-0.641).  For the daily living skills domain, the significant correlations were with the play (-0.458), and the repetitive/stereotyped behavior (-0.46). The highest and strongest correlations with all the VABS domains were for the ADOS repetitive/stereotyped behavior scores. All the correlations were significant (p<0.01), indicating negative relationships with the daily living skills (-0.46), socialization (-0.485), and communication (-0.641) domains. Sequential regressions were run for each adaptive behavior domain . For VABS socialization domain, ADOS play score was the most predictive variable accounting for 33% of the variance for this domain. For VABS communication, all the ADOS scores were significant predictors, being the play score the most significant predictor (49.9%), followed by the total sum of communication and reciprocal social interaction (39%).  The VABS daily living skills were also best predicted for the stereotyped behavior and restricted interests’ scores, contributing to 34% of the variance.

 Conclusions: Communication adaptive skills were predictive of all autism symptoms, whereas socialization adaptive skills showed no significant relationship with them.  Play and stereotyped behaviors might be an important element in the diagnostic process, since it predicted communication and socialization adaptive behaviors. The findings of this study highlight the need to have a better understanding of the relationships between adaptive behaviors and autism symptoms, so the planning of treatment will have an effect on children´s everyday functioning.