Inhibitors of serotoninergic reuptake on  Inclusion Criteria:  patients over 18 years old patients undergoing elective cardiac surgery patients diagnosed with depressive syndrome requiring treatment with Inhibitors of serotoninergic reuptake excluding neurodegenerative diseases patients on antidepressant therapy for more than 3 months at the time of enrollment  Exclusion Criteria:  absence of written informed consent to the study patients undergoing non-elective and emergency cardiac surgery patients undergoing off pump surgery patients with depression not on therapy patients with existing malignancies patients with acute infections in progress patients with previous stroke, cerebral haemorrhage with relics patients with acquired and congenital metabolic pathologies with CNS alterations Patients with acute and / or chronic renal failure according to RIFLE score (exclude only F-L-E) Patients with acute and / or chronic hepatic insufficiency according to Child - Pugh score <6 (but without encephalopathy); Patients with neurodegenerative diseases (dementias of all types both organic and vascular, parkinson's and ongoing delirium); Patients with previous or current drug and / or alcohol abuse pregnant or postpartum period patients (6 months after delivery)  Inhibitors of serotoninergic reuptake off  Inclusion Criteria:  patients over 18 years old patients undergoing elective cardiac surgery patients without a diagnosis of depressive and psychiatric illness requiring treatment with psychoactive drugs to the exclusion of neurodegenerative diseases  Exclusion Criteria:  absence of written informed consent to the study patients undergoing non-elective and emergency cardiac surgery patients undergoing off pump surgery patients with depression not on therapy patients with existing malignancies patients with acute infections in progress patients with previous stroke, cerebral haemorrhage with relics patients with acquired and congenital metabolic pathologies with CNS alterations Patients with acute and / or chronic renal failure according to RIFLE score (exclude only F-L-E) Patients with acute and / or chronic hepatic insufficiency according to Child - Pugh score <6 (but without encephalopathy); Patients with neurodegenerative diseases (dementias of all types both organic and vascular, parkinson's and ongoing delirium); Patients with previous or current drug and / or alcohol abuse pregnant or postpartum period patients (6 months after delivery)