Against the background of the aging population and the rise in the incidence of diabetes mellitus, there is an increase in complications, including those related to the central nervous system. Today, diabetes mellitus remains a socially significant nosology, since the therapy of long-term complications of diabetes mellitus is ineffective due to insufficient study of the mechanisms of multifactorial pathogenesis. The purpose of this literature review is to summarize modern scientific data on morphofunctional changes in the brain in diabetes mellitus.