Concordance in salivary cortisol and subjective anxiety to the trier social stress test in social anxiety disorder

Background
Social anxiety disorder (SAD) is characterised by an excessive fear of negative social evaluation. There is a limited understanding of how individuals with SAD react physiologically and subjectively to social stress.

Method
The Trier Social Stress Test (TSST), an acute social stress task, was completed by 40 SAD individuals (50% female) and 41 healthy controls (matched on age, sex, and education) to examine salivary cortisol and self-reported stress reactivity. Salivary cortisol concentrations and self-reported affect (anxiety, sadness, tiredness, withdrawal, and happiness) were assessed at baseline and across nine-time points during the TSST.

Results
Bayesian salivary cortisol analyses revealed no group differences in salivary cortisol levels at baseline or during the TSST, with results comparative after the removal of 17 cortisol non-responders (21%). Contrastingly, the groups significantly differed on self-reported affect. At baseline, the SAD group (vs. controls) reported heightened negative affect and diminished happiness. In response to the TSST, the SAD group (vs. controls) displayed greater negative affect reactivity and diminished happiness reactivity, and significantly higher rates of change in their anxiety and sadness over time. After accounting for differences in the temporal resolution of self-reported versus cortisol responses, a moderate positive association was found between salivary cortisol and anxiety reactivity to social stress that was comparable between the groups.

Conclusions
Despite elevated subjective anxiety, our findings suggest concordance in psychobiological stress reactivity in SAD and healthy controls. We discuss the possibility of heightened subjective sensitivity to social evaluative stress as a core treatment target for SAD.