Stress-induced cortisol level elevations are associated with reduced negative affect after stress: indications for a mood-buffering cortisol effect.

OBJECTIVE Stress is associated with increased negative affect and activation of the sympathetic nervous system and of the hypothalamic-pituitary-adrenal axis. However, the relationship between these stress systems and negative affect is incompletely understood. We therefore investigated positive and negative affects in relationship with salivary cortisol and salivary α-amylase (sAA) levels in a large sample of participants exposed to a psychosocial stressor or a control condition. METHODS Cortisol and sAA levels from five studies with a total sample size of 232 participants were reanalyzed using hierarchical linear modeling. In these studies, we measured affective responses to the Trier Social Stress Test (TSST) and its control condition (placebo TSST) with the Positive and Negative Affect Schedule. RESULTS An inverse relationship between cortisol and negative affect was observed across all participants (β(06) = -0.13, p = .002). Higher level of negative affect was associated with lower mean cortisol levels 10 minutes after the TSST or the control condition. When the two conditions were tested separately, the effect was significant in the stress condition (β(06) = -0.05, p = .02) but not in the control condition (β(06) = -0.0008, p > .05). In contrast to the results for cortisol, a positive relationship was found between sAA and negative affect within the stress condition (β(06) = 0.10, p = .005). CONCLUSIONS The present findings suggest that cortisol is associated with an attenuated negative emotional arousal in response to acute stress, whereas sAA levels seem to reflect the degree of negative emotional arousal. Together with previous pharmacological studies, these data seem to support the hypothesis of mood-buffering effects of cortisol.