Differential effects of mild chronic stress on cortisol and S-IgA responses to an acute stressor

While acute stress is adaptive in the short term, chronic stress may interfere with HPA axis functioning and self-regulation that can, in turn, alter the body's immune response. Several studies suggest that acute and chronic stress consistently increase cortisol levels; however, the same cannot be said about S-IgA levels. We tested the effects of a mild chronic stress (an academic exam period), on cortisol and S-IgA responses to an acute stress. Exposure to an acute stressor significantly increases cortisol levels during periods of no-stress, but not during mild chronic stress, while S-IgA levels consistently increase during both sessions. Furthermore, we find that during the period of chronic mild stress, the perception of stress is related to increased cortisol response to an acute stressor. Combined, these findings shed light on the impact of increased background stress on acute stress responses.