Objective. The high level of comorbidity of coronary heart disease (CHD) and depressive disorders and general aspects of their pathogenesis is an actual problem of modern research. Authors studied the content of cholesterol, platelet serotonin, platelet aggregation, activity of pro-inflammatory markers in CHD patients with comorbid depressive disorders. Material and methods. The study included 76 patients with CAD. The diagnosis of depressive disorder was set according to ICD-10, The Hamilton depression scales was used. Results and conclusion. Depressive disorders in CHD patients were associated with an increase in the activity of pro-inflammatory markers (IL-6 and TNF-α), and with high levels of low density lipoproteins. In patients with CAD and depressive disorders with high contents of platelet serotonin, the level of cholesterol was higher compared to those with low contents of serotonin. No significant differences in the functional platelet activity were identified in patients with CAD and comorbid depression compared to patients without mood disorders.