Psychiatria pre prax 3/2023

Stress, inflammation and depression – the search for correlations

One of the most encouraging and widely publicised discoveries in recent years is the discovery of a positive correlation between the presence of depression and anxious symptoms and higher blood-circulating inflammatory cytokines, specifically Interleukin-6. Proinflammatory cytokines are considered anxiogenic and depressogenic. Increases in inflammatory markers in depressed patients may indicate a population that is relatively resistant to treatment. It is noteworthy that individuals with autoimmune illnesses exhibit remarkably elevated prevalence rates of depression. The discovery that pro-inflammatory vs anti-inflammatory immunoregulatory cytokines are produced in response to psychosocial stressors has significant consequences for stress-related illnesses, including depression. A dysregulated immune response involving myeloid innate immune cells from peripheral tissues (monocytes, macrophages, and neutrophils) and the central nervous system (microglia), as well as adaptive immune cells (T cells), dysbiosis of host commensals and infection from exogenous pathogens, and abnormal neuroendocrine signalling may increase the production of inflammatory mediators in the circulation and brain, increasing the potential risk of depression, anxiety, and suicide. In line with all those findings is a co-inhibition of depressive symptoms and inflammation, which was also observed with antidepressant treatment.

Keywords: stress, inflammation, depression, anxiety, imunity, hormonal regulation, antidepressants