Abstract
The review article examines the biological factors and pathophysiological mechanisms that contribute to the formation of suicidal behavior. The stress of modern life, being psychosocial at its core, is realized through certain biological mechanisms that affect the biological essence of a person. According to numerous literary sources, in case of suicide, not only the central nervous system is involved in the pathological process, but also various peripheral components - metabolic systems of the body, such as peripheral serotonin, tryptophan, neurokynurenines and cortisol. In addition, the contribution of the inflammatory process in mental disorders, which is an important factor in suicide, is of interest, in particular, immunity, the cytokine system, neurohormonal reactions, and also as a component of the gut-brain axis, intestinal microflora. All these connections are multifaceted and have implications for the search for peripheral markers of suicidality. A comprehensive literature search was conducted using the Web of Science, PubMed, Scopus, and eLibrary databases.