Stress and the Immune System: Mechanisms, Types of Interactions, and Adaptation

The effects of stress on human immune system are complex: they are dynamic, and derive from neuroendocrine-immune interactions. Activation of the HPA axis and the SNS leads to the production of cortisol and catecholamines which, in their own right, have the ability to alter immune cell trafficking, cytokine release, and inflammatory signaling (Dhabhar, 2018; Slavich & Irwin, 2014). Short-term stress can activate immune surveillance by mobilizing lymphocyte and natural killer cell activity, but long-term stress results in a constant exposure to glucocorticoids, which dampens the adaptive immune response, upsets the balance of cytokines, and maintains systemic inflammation (Cohen et al., 2022; Pedersen et al., 2021). This dysregulation impairs immunity to infections, slows cut healing, impedes the effectiveness of vaccination, and worsens chronic diseases including autoimmune diseases, cardiovascular diseases, and cancer (Segerstrom & Miller, 2004; Chida et al., 2008). Further, psychosocial and behavioral factors interact in the way chronic stress impacts neuroimmune pathways which have an effect on the outcomes of mental health (Slavich & Irwin, 2014). These findings suggest that integrative stress management approaches, such as cognitive-behavioral therapy, mindfulness-based stress reduction, and lifestyle interventions, could promote immune resilience and health.