The article presents epidemiological study data on depressive disorders prevalence and dynamic of the population emotional well-being and affective disorders incidence in the world during the COVID 19 pandemic. Typical anxiety-depressive states are described with the emphasis on the specific COVID 19 stress syndrome. The article highlights the depression evolutional model as an adaptation mode to the unfavorable defined environmental conditions with the limited life-supporting resources, the nowadays pandemic situation can be definitely considered as one of them. The research data uniting psychodynamic and biological approach are considered in particular genetic specific of the serotoninergic regulation and environmental influence of the early adverse experience vulnerability with the later depressive disorders manifestation Additionally the research results on the bidirectional relationships between affective and immunological disturbances with the immune-metabolic syndrome description are presented. The peculiarities of the depression patients cognitive functioning are identified with specific personal negative rigid cognitive style and executive cognitive functions consideration. The combined therapy algorithm including implementation of SSRI antidepressants and cognitive-behavior psychotherapy, cognitive remediation programs is proposed.