The role of cellular immunity and systemic inflammation indices in the pathogenetic mechanisms of mental disorders

To date, inflammatory mechanisms are known to be involved in neuronal damage and increased risk of associated mental disorders, but most previous work has focused primarily on cytokines and other inflammatory markers that are difficult to replicate and not economically feasible for use in routine clinical practice. Other extremely important indicators of the systemic inflammatory process are circulating blood cells and changes in their number, composition, and ratio. Hematologic indices of systemic inflammation (HISI) are already used in somatic specialties: neutrophil-lymphocyte (NLR), monocyte-lymphocyte (MLR) and platelet-lymphocyte (PLR) ratios, as well as the Systemic Immune Inflammation Index (SII) and the System Inflammation Response Index (SIRI). In the context of psychopathology, the HISI require additional investigation, which makes it necessary to pay more attention to the possible mechanisms underlying their changes. The article provides data on the contribution of each cellular element to the mechanism of neuroinflammation and neurodegeneration and on their role in the development of psychopathological processes.