During treatment, there was an improvement in neurophysiological parameters in both groups, which was more pronounced in patients treated with cytoflavin: their P300 amplitude increased by1.3 times in the left hemisphere (from 9.21 (8.36, 10.11) to 12.41 (10.23, 13.37 μV) and 1,7 times in the right hemisphere (from 6.48 (5.26, 7.35) to 11.04 (9.29, 12.18) μV). Our study confirms the advisability of using drugs that have complex cytoprotective and energy-correcting mechanism in patients with cognitive impairment. Cytoflavin has shown the high efficacy and safety and can be recommended as part of complex therapy for cognitive disorders. Using simple and inexpensive instrumental methods (assessment of cognitive P300 evoked potential) along with diagnostic scales in patients with cognitive impairment can significantly objectify the assessment of treatment dynamics.