Perception of Life As Stressful, Not Biological Response to Stress, Predicts Greater Social Disability in Adults with Autism Spectrum Disorder

Background: Poor social functioning is a central feature of autism spectrum disorder (ASD) and has far-reaching effects on multiple domains of life. Yet, we know little about modifiable factors that predict social functioning in this population. Preliminary work suggests that there may be differences in the underlying mechanisms that drive stress management in individuals with ASD and that these differences may be associated with adult outcomes.

Objectives: This study aimed to (1) identify differences in stress response among adults with ASD and healthy volunteers; and (2) examine the relationship between stress response and social functioning adults with ASD. We hypothesized that adults with ASD would experience greater biological stress, perceived stress, and stressful life events 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 (Perceived Stress Scale), stressful life events (Stress Survey Schedule), social disability (Social Adjustment Scale-II), daily living skills (Waisman Activities of Daily Living), and social impairment (Social Responsiveness Scale). Analyses examined group differences between adults with ASD and healthy volunteers on biological stress response variables (SBP, DBP, and HR growth coefficients and salivary cortisol change scores) and self-reported stress variables (perceived stress and stressful life events). The relationship between biological stress response and psychosocial stress variables and social functioning variables (global functioning, social impairment, social disability, and daily living skills) was analyzed using hierarchical multiple regression procedures.

Results: Results indicated that adults with ASD experienced significantly more perceived stress, F(1, 63)=23.13, p<.001, and stressful life events, F(1, 63)=25.90, p<.001, and greater SBP reactivity, F(1,63)=4.95, p<.05 but did not differ from healthy volunteers in terms of DBP reactivity, HR reactivity, or cortisol reactivity. Results of regression analyses indicated that perceived stress, β=0.07, t(35)=3.16, p<.05, and stressful life events, β=0.02, t(35)=3.20, p<.05, significantly predicted social disability, when controlling for age, IQ, and treatment exposure. However, none of the biological stress response variables significantly predicted any social functioning variables, and perceived stress and stressful life events did not predict social impairment or daily living skills.

Conclusions: These results suggest that, while adults with ASD experience both greater systolic blood pressure reactivity and greater perceived stress and stressful life events than healthy volunteers, the perception of life as stressful is associated with social disability in this population while measured biological response to stress is not. Future research should examine both the directionality of the association between perceived stress and social functioning and interventions designed to help adults with ASD experience and respond to stress differently.