Objective. Naturalistic psychopharmacological study of efficacy and tolerability of agomelatine (valdoxan) in treatment of endogenous depressions (in the framework of schizophrenia, schizoaffective and bipolar disorder) in day patient department. Material and methods. Study sample consisted of 37 patient (59.4% female, mean age 41.6±3.7 years). Results and conclusion. CDS total score significantly reduced after 8 weeks of treatment 44.9% compared to baseline (р<0.001); HAM-D total score decreased on 51.3% compared to baseline (р<0.001). The proportion of responders at the 8th week of treatment was 54.1%. Agomelatine (valdoxan) had favorable safety profile. Follow-up study (up to 24 months) showed stable antidepressive effect and good tolerability profile of agomelatine (valdoxan). There was no withdrawal syndrome after treatment discontinuation.