Background: chronic endogenous depression in youth has a number of features associated with their severe atypia, work and social maladjustment, deterioration in the quality of life, high risk of suicidal and self-injurious behavior, difficulties in choosing therapy, difficulty in diagnosis and nosological evaluation. Until now, no special research has been done on chronic endogenous depression among young people of this age.Purpose of research: to identify psychopathological features and dynamics of endogenous depression developed in youth, to work out a clinical typology. Patients: 62 young patients (16–25 years old) were clinically and psychopathologically examined, who were first admitted to FSBSI MHRC, within the period of 2017 to 2020 suffering from chronic endogenous depression state for more than two years. Clinically significant somatic, neurological, and mental pathology defined the criteria for exclusion.Methods: for the research the clinical-psychopathological and psychometric methods were used. The patients were examined by the psychometric method upon admission to the hospital and at the stage of reduction of psychopathological disorders upon discharge: the HDRS, SANS and SOPS scales included.Results and conclusion: the clinical picture of youth chronic endogenous depression is characterized by pronounced polymorphism, atypia, erosion of the thymic component, and the dominance of negative affectivity. Based on the analysis of psychopathological characteristics of endogenous depression in youth, two typological varieties were identified: unitary depressions (type I) and supplementary depressions (type II). Among the type II depressions, 2 subtypes were distinguished: with neurosis-like disorders and with psychopathic-like disorders.