Authors studied 160 patients with chronic hepatitis C on antiviral treatment. Depressive disorders developed in 85 patients. Clinical and pharmacotherapeutic features of depression were specified. Predictors for the prevalence, structure and severity of the depressive syndrome were found. The clinical and demographic heterogeneity of depressions was identified. The results of the clinical and statistical analysis allow to specify the nosological qualification of these depressions, to optimize diagnostic and treatment algorithms and to make more effective treatment of the main disease (chronic hepatitis C).