INTRODUCTION: The presented literature review is devoted to neurochemical, immunological and genetic aspects of the formation of anxiety and depression. The aim of the review was integration of the available knowledge on the topic to present it in a more systematized form and evaluate the existing scientific data on the topic. The review is non-systematic. It included the international and domestic literature sources, databases, the results of studies posted on the PubMed portal on the Internet, in the scientific electronic library e-Library. The search depth was 30 years (from 1993 to 2023). The review incorporated sources that satisfied the topic of the work. A deeper studying of anxiety and depression showed involvement of a number of systems in their formation: serotoninergic, noradrenergic, dopaminergic and other neurotransmitter systems, which leads to formation of neuroinflammation. There is also data on the interrelation between the immune and psychopathological statuses. The infectious component of the pathology cannot be excluded either. On the other hand, there is evidence of the involvement of AB (0) blood system in the occurrence of the above condition. Of special attention are publications showing a mediated influence of genetic factors on the course of anxiety and depression. CONCLUSION: There are a number of hypotheses confirming a close link between the functioning of the regulatory systems (endocrine, immune, central nervous system) and disorders that entail anxiety and depressive disorders. In result, the existing knowledge on the topic was presented in a more systematized form.