124 patients with diabetes mellitus were examined in hospital of endocrine profile. The borderline mental disorders were revealed in 115 cases (92,7%) in the form of neurosis-like disturbances and pathological development of personality. Asthenic, asthenohypochondriac, asthenodepressive, obsessive and hysteroformic syndromes were diagnosed in patients with neurosis-like disorders. The personal disorders included asthenic, hysteric, obsessive, explosive and psychosomatic variations of development of the personality. Besides, poor cooperation of patients with the doctor was observed in the course of ''diabetic control''.