Social Support As a Moderator of the Relation Between Sibling Relationship Attitudes and Depressive Symptoms Among Typically-Developing Adult Siblings of Those with Autism Spectrum Disorder

Background:  Literature examining typically-developing (TD) siblings of individuals with autism spectrum disorder (ASD) remains inconclusive.  Some studies suggest siblings may experience maladjustment, others suggest possible benefits, whereas others have found no differences in overall development (Meadan et al., 2010).  Thus, it has been suggested that future research should focus on identifying specific risk and protective factors for TD sibling adjustment.  Early sibling interactions and attitudes are thought to have potentially longstanding influences on behavior and development across the lifespan (Cicirelli, 1995; Riggio, 2000).  Perceptions of high levels of social support have also been found to act as a buffer against stressors, protecting individuals from negative outcomes (Armstrong et al., 2005).  Because TD adult siblings often eventually take over care of their siblings with ASD (Orsmond & Seltzer, 2007), examination of factors related to TD sibling well-being warrants consideration. 

Objectives:  The purpose of the current study was to examine perceptions of social support as a potential protective factor against depressive symptoms among TD adult siblings of those with ASD.  It was predicted that perceptions of social support would moderate the relation between child and adult attitudes about the sibling relationship and depressive symptoms. 

Methods:  Fifty-three typically-developing adult siblings [ages 18-68 (M = 30.58, SD = 13.7); 85% female] of individuals with an ASD participated.  Siblings completed a demographic form, the Interpersonal Support Evaluation List (ISEL) to assess perceived overall social support, the Lifespan Sibling Relationship Scale (LSRS; Riggio, 2000) to assess child and adult attitudes about the sibling relationship, and the Depression Anxiety Stress Scales (DASS; Lovibond & Lovibond, 1995) to assess current depressive, anxious, and stress symptoms.

Results:  Two separate moderated multiple regression analyses were conducted with sibling gender, age, income, and childhood family size entered in Step 1 as controls.  After centering the scores, the predictor variables and moderator variables were entered in Step 2.  The interaction terms were entered in Step 3.  Results of the first analysis revealed a significant interaction between TD sibling perceptions of social support and TD sibling child relationship attitudes when predicting depressive symptoms in TD siblings, ΔF(1, 45) = 9.19, p = .004, ΔR² = .088.  Results of the second analysis revealed a significant interaction between TD sibling perceptions of social support and TD sibling adult relationship attitudes when predicting depressive symptoms in TD siblings ΔF(1, 45) = 4.44, p = .041, ΔR² = .045.  As expected, interaction plots of both analyses showed that TD siblings who exhibited more negative child and/or adult sibling relationship attitudes and lower levels of perceived social support were more likely to have higher levels of depressive symptoms. 

Conclusions:   As predicted, perceptions of social support moderated the relations between child and adult sibling relationship attitudes and depressive symptoms among TD adult siblings of those with an ASD after controlling for sibling age, gender, income, and childhood family size.  Overall, these results suggest that those siblings with negative attitudes about their sibling relationship and low levels of perceived social support may be at greater risk for depressive symptoms.