Eating disorders of bulimic type are among the most common comorbidities with depression. The objective is to evaluate cognitive function and mood dynamics in patients with depression and eating disorders in pharmacotherapy. In total, 52 outpatients, who met criteria for “major depressive episode” (ICD-10), participated. The level of depression was estimated with Hamilton Depression rating scale (HAM-D) and cognitive function–Montreal Cognitive Assessment (MoCa). Sample was divided into two groups. Patients of group 1 also met criteria for eating disorder of bulimic type and patients of group 2 did not have any eating disorder. Treatment included standard doses of SSRI. Assessments were performed after 2, 4 and 8 weeks (D14, D30, D60). The level of HAM-D was significantly greater (P < 0.05) in eating disorders group (16.75 ± 2.83 in group 1; 13.04 ± 1.93 in group 2 at screening) and significance was preserved till D60 (9.39 ± 2.54 in group 1; 6.32 ± 1.27 in group 2 at D60). Clinically significant antidepressive effect was revealed faster in group 2 (at D7) compared to group 1 (at D14). Overall score of MoCA was significantly lower (P < 0.05) in eating disorders group (20.33 ± 0.54 in group 1; 23.43 ± 2.32 in group 2 at screening) at all stages of treatment (23.39 ± 0.78 in group 1; 26.96 ± 3.27 in group 2 at D60) and it reached normal range (25 and more) only in group 2 at D60. Significant change from screening was revealed at D30 at group 2 and at D60 at group 1.