A complex study of neurocognitive traits, depression symptoms, clinical and anamnestic characteristics and metabolic status of patients with diabetes mellitus (DM) with diabetic encephalopathy (DE) of stage I-II has been conducted. Patients with DE had relatively impaired memory and attention as compared to patients without DE. Nonverbal intellect scores were similar in both groups and did not differ from those for "good norm". Development of DE was related to increasing depressive "dissatisfaction", "fatigability", loss of libido and intensification of emotionally-colored complaints about physical health as well as to the relative increase of atherogenic index and glycemia on one of day curve points. An equation of discriminative function that allowed objective assessment of DE diagnosis by clinical and instrumental data was obtained.