Discrepancy in Social Support Perceptions As a Risk Factor for Siblings of Individuals with ASD

Background: Typically-developing (TD) siblings of individuals with ASD are at risk for negative outcomes due to a variety of factors. One such factor is the severity of their sibling’s ASD deficits (Meyer et al., 2011). Social support has been identified as a protective factor against these deficits on sibling adjustment (Hastings, 2003). However, the availability of support may not be as meaningful as the discrepancy between one’s perceived importance of support and the amount of support available (Newcomb, 1990). Further, social support encompasses many distinct domains of support. Research in other populations illustrates that different forms of support may have differential effects on physical and mental health (Wong et al., 2014). However, social support discrepancy has not been examined in the adjustment of TD siblings of children with ASD.   

Objectives: This study explored: 1) If social support discrepancy moderates the relation between ASD symptom severity in siblings with ASD and TD sibling adjustment problems, overall, and in terms of emotional and externalizing problems. 2) Which domain(s) of support discrepancy uniquely predict(s) TD sibling adjustment, while controlling for ASD symptom severity in siblings with ASD. 3) If the relation between ASD symptom severity in siblings with ASD and TD sibling adjustment is moderated by the unique domain(s) of support.  

Methods: 113 Families completed study measures. Parents completed the Children’s Social Behavior Questionnaire (CSBQ) about the child with ASD, assessing ASD symptom severity. TD siblings (Mage = 13.33, 50% male) self-reported emotional and behavioral functioning via the Strengths and Difficulties Questionnaire (SDQ), and social support availability and importance via the Child and Adolescent Social Support Scale (CASSS).  

Results: Moderated multiple regression analyses were conducted to examine interactions via the computational tool, PROCESS (Hayes, 2013).  Significant interactions emerged between ASD symptom severity and greater social support discrepancy (coded: importance minus availability) when predicting overall sibling maladjustment, B = .09, SE = .04 p = .03, and emotional problems, B = .04, SE = .02 p = .01. Separate regression analyses (Table 1) revealed that emotional support discrepancy was the only unique predictor of overall sibling adjustment,β = .51, p = .001, and externalizing and emotional problems (both β > .37, both p < .02).  Finally, significant interactions between ASD symptom severity and emotional support discrepancy emerged predicting overall sibling maladjustment, B = .10, SE = .04, p = .01 (Figure 1), and both emotional, B = .04, SE = .02, p = .02, and externalizing problems, B = .03, SE = .01, p= .03.  

Conclusions: Social support discrepancy moderates the relations between ASD symptom severity and overall and emotional adjustment problems in TD siblings. This was driven by emotional support discrepancy, which also moderated the relation between ASD symptom severity and externalizing problems. Findings highlight that support discrepancy may be more predictive of sibling adjustment than actual perceived support. Further, emotional support may be a particularly useful area to target for siblings and has unique predictive value over and above total and other domains of support discrepancy.