Psychosocial Outcomes Among Adult Siblings of Individuals with ASD and Other Developmental Disorders: Support for Potential Risk/Protective Factors and Points of Intervention

Background: Typically-developing (TD) adult siblings are often tasked with caring for their siblings with ASD or other developmental disability, both during childhood and in adulthood (e.g., Heller & Kramer, 2009). Given genetic (e.g., broader autism phenotype) and environmental (e.g., increased burden) risk factors, conventional thinking suggests that TD adult siblings may be at increased risk for negative outcomes.  However, research on TD child siblings has found wide variability in childhood psychosocial constructs (e.g., Meadan et al., 2010; Orsmond & Seltzer, 2007). These discrepancies suggest that negative outcomes only occur under certain conditions; however, little research has examined TD siblings during adulthood.   

Objectives:   This presentation aims to provide descriptive information about psychosocial outcomes among a sample of adult siblings of individuals with ASD and/or intellectual disabilities (IDs). Possible risk and protective factors and points of intervention will be discussed.  Finally, examination of differences according to sibling disability type and indirect effects of diagnostic group inclusion through sibling relationship attitudes on psychosocial outcomes will be presented.

Methods:   105 TD siblings (Mage = 33.04, SD = 14.13) completed a demographic form, the Depression Anxiety and Stress Scale (DASS; measure of distress in siblings), the Parentification Inventory (PI, measure of childhood parentification), the Interpersonal Support Evaluation List (ISEL, measure of social support), the Lifespan Sibling Relationship Scale (LSRS; measure of sibling relationship attitudes) and the Satisfaction with Life Scale (SLS; measure of life satisfaction).

Results:    Descriptive statistics and correlations among the variables of interest will be presented to provide context.  For specific mediation analyses, covariates were determined a priori and entered into the models where necessary. A series of multiple regression analyses revealed that sibling relationship attitudes predicted several outcomes in TD siblings across both groups: level of assistance provided, ΔF(5, 76) = 7.65, p = .01, ΔR² = .07; life satisfaction, ΔF(3, 78) = 6.39, p = .01, ΔR² = .07, depression ΔF(3, 77) = 9.33, p = .003, ΔR² = .09, and stress, ΔF(3, 78) = 4.78, p = .03, ΔR² = .05. TD siblings in the ASD group reported significantly fewer positive sibling relationship attitudes compared to siblings in the ID group.  Using bootstrapping analytical methods via Hayes’s PROCESS macro (Hayes, 2013), indirect effects of group membership on assistance [point estimate = -.93 (95% CI [-2.26, -.22])], depression [point estimate = 2.00 (95% CI [.52, 4.53])], and stress [point estimate = 1.52 (95% CI [.25, 3.61])] in TD siblings through sibling relationship attitudes were identified (Figure 1). 

Conclusions:   Overall, TD siblings’ report of outcomes varied, with some differences related to the type of disability (ASD or ID) experienced by the affected sibling. Over and above demographic correlates, sibling relationship attitudes appear to be an important predictor of psychosocial outcomes among TD adult siblings.  Moreover, the identified indirect effects suggest that sibling relationship attitudes may be a particularly salient point of intervention for improving sibling functioning, particularly among siblings of individuals with ASD.  Clinical implications of other identified risk- and protective-factors (e.g., low or high social support) will also be discussed.