Social Functioning in Adults with Autism: The Role of Biological Stress Response, Perceived Stress, and Stressful Life Events

Background and Purpose: Poor social functioning is a central feature of autism spectrum disorder (ASD) and has far-reaching effects on multiple domains of life for affected individuals. Yet, we know little about modifiable factors that predict social functioning in this population. This study aimed to improve our understanding of the biological and behavioral underpinnings of adult outcomes in ASD by (1) identifying differences in stress response among adults with ASD and healthy volunteers; and (2) examining the relationship between stress response and social outcomes adults with ASD. We hypothesized that adults with ASD would experience greater biological and psychosocial stress than healthy volunteers and that there would be a significant relationship between stress and social functioning in adults with ASD.

 

Methods: Cross-sectional data were collected from 40 adults with ASD and 25 healthy volunteers. Participants with ASD were ages 18-44 (M=24.2), had intelligence quotient (IQ) scores from 80-132 (M=106.3), and 90.0% male. Healthy volunteers were ages 18-32 (M=25.1), had IQ scores from 82-138 (M=110.6), and 84.0% male. Repeated measures of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were taken during a social stress challenge task, while salivary cortisol was collected before and after the task. Measures also assessed perceived stress, stressful life events, global functioning, social disability, daily living skills, and social functioning. Analyses examined group differences between adults with ASD and healthy volunteers on z-metric composite scores of biological stress response (SBP, DBP, and HR growth coefficients and salivary cortisol change scores) and psychosocial stress (perceived stress and stressful life events) using analysis of variance procedures. The relationship between stress response and social functioning (z-metric composite of global functioning, social disability, daily living skills, and social functioning) was analyzed using hierarchical multiple regression procedures separately for biological and psychosocial stress response.

 

Results: Results indicated that adults with ASD experienced significantly more psychosocial stress than healthy volunteers, F(1,60)=33.13, p<.001, and greater biological stress response, F(1,60)=5.97, p<.05, than healthy volunteers when controlling for IQ and sex. Results of regression analyses indicated that psychosocial stress, β=-.26, t(35)=-2.02, p<.05, but not biological stress response, β=-.04, t(35)=-.25, p=.801, significantly predicted social functioning when controlling for IQ and sex.

 

Conclusions and Implications: Findings indicate that adults with ASD experience significantly greater psychosocial stress and biological stress response than healthy volunteers and that psychosocial stress significantly predicts social functioning in adults with ASD. These results suggest that, while adults with ASD experience both greater biological stress response and experience greater psychosocial stress than healthy volunteers, the lived experience of stress may have a greater influence on social functioning than biological stress response in this population. Future research should examine interventions that might improve social functioning by helping adults with ASD experience stress differently.