Sibling Status (TD or ASD) Is Associated with Parent Reports of Adaptive Skills in Children with ASD

Background: Previous research has focused on the impact of having a sibling with autism spectrum disorder (ASD) on typically developing (TD) children. Findings suggest that having an ASD sibling is associated with increased adjustment problems, peer problems, internalizing and externalizing behaviours and less prosocial behaviour in TD children (Hastings, 2003; Ozonoff et al., 2010). However, little research exists on how the effect siblings have on the behaviour of children with ASD. In the current study we examined adaptive skills of children with ASD who had a TD sibling vs. a sibling with ASD. Children with ASD generally show poor adaptive skills (Gillberg, 2002), even those with average intellectual functioning show adaptive behaviour in the “at risk” range (Volker et al., 2010). In this study we assessed adaptive skills including adaptability, social skills, leadership, activities of daily living, and functional communication in children with ASD who had a TD sibling and inthose who had an ASD sibling.

Objectives: To investigate whether sibling status (i.e., TD or ASD) is associated with different levels of adaptive skills in children with ASD

Methods:  Participants were 40 children with ASD between the ages of 6 and 17 years old (M=11.4; SD=2.4) who have one sibling (agerange = 6–21 years; M=12.1; SD=2.4) with ASD (n=12), or one TD sibling (n=27). The parents ratedtheir children's adaptive skills on the Behaviour Assessment System for Children Second Edition (BASC-2), and ASD symptoms on the Social Responsiveness Scale (SRS). Children’s IQ scores were assessed using the Wechsler Abbreviated Scale of Intelligence (WASI-II), or Stanford-Binet Intelligence Scales, abbreviated version (SB5).

Results:  Hierarchical multiple linear regression analyses indicated that sibling status was a significant predictor of Adaptive Skills in children with ASD, above and beyond ASD symptoms, IQ, siblings age, and participants age. Specifically, having a TD sibling accounted for a significant additional 19% of the variance in adaptive skills (.To further explore this relationship we examined the subscales of the Adaptive Skills. Certain subscales remained significant, Adaptability(, Activities of Daily Living (,and Functional Communication (. In contrast, social skills and leadership subscales did not reach significance.

Conclusions: In children with ASD, having a TD sibling is a significant predictor of higher scores on Adaptive Skills including Adaptability, Activities of Daily Living and Functional Communication. These results suggest that TD siblings may have an important role to play in the daily functioning of children with ASD. Having a TD sibling may provide opportunities for modeling of adaptive behaviour in children with ASD and sibling mediated interventionsmay be a potentially powerful tool for teaching adaptive skills to children with ASD.