The monograph summarizes the results of clinical and extraclinical studies conducted over the past two decades in St. Petersburg NIPNI named after V.M. Bekhterev regarding negative and cognitive disorders in endogenous psychoses. The presentation of clinical material is given in several aspects: typology of negative disorders (primary secondary), typology of manifestations of cognitive deficit, features of the formation of one and another group of disorders in different forms of schizophrenia and affective psychoses, including consideration of the criteria for their differential diagnosis and new approaches to drug and psychosocial correction.