Biomarkers of endogenous mental disorders: the role of cortisol, extracellular DNA, BDNF, and cytokines in relation to disease stage and therapy

Background. With the growing number of publications on the search for biological markers of mental disorders, it is important to analyze studies on the role of extracellular DNA, cortisol, cytokines, and the BDNF as markers of the severity of endogenous mental disorders, depending on disease stage and antipsychotic treatment. Purpose: to analyze available data on the relationship between biomarkers of endogenous mental disorders (cortisol, cytokines, extracellular DNA, and BDNF) and disease stage, as well as antipsychotic therapy. Materials and method. Publications accessible to the authors were selected from MEDLINE/PubMed, Scopus, Crossref, eLibrary, and RSCI databases using the key words “biomarkers of mental disorders”, “stress and cortisol”, “cytokines and mental disorders”, “BDNF”, “extracellular DNA”. A total of 428 sources were identified, and 71 were selected, primarily from 2020 to 2024, focusing on the impact of biological marker levels on the progression of mental disorders and their changes under therapy. Priority was given to meta-analyses and systematic reviews, which reflect recent discoveries and can significantly influence future research directions. Conclusion. The review analyzes studies of biomarkers in patients with endogenous mental disorders and their associations with stress, autoimmune disturbances, disease stage (first episode, long-term course, relapse, or remission), and therapy, as well as the influence of biomarker levels on the severity of clinical manifestations of mental illness. Correlations were identified between specific biomarker levels and cognitive impairments, positive symptoms, and negative symptoms. Research on biomarkers of endogenous mental disorders aims to enable early diagnosis, develop new therapeutic targets, and stratify patients for optimal therapeutic protocols, providing new opportunities to address clinical, diagnostic, therapeutic, and rehabilitative challenges.