The mechanisms of oxidative stress and inflammation involved in mood disorders are factors of chronicity and severity. These mechanisms induce a phenomenon of accelerated cellular senescence and are reflected by alterations in systemic gene expression detectable in leukocytes in peripheral blood. The genetic markers of these mechanisms are clinically significant markers. The identification of new genetic markers will make it possible to improve evaluations of the severity and somatic consequences of depressive syndromes.

Inclusion Criteria:

• Persons who have given their written informed consent
• absence of a diagnosis of major depressive disorder throughout the study and no history of psychiatric disorders
• diagnosis of a first episode of a major depressive disorder
• diagnosis of a recurrent major depressive disorder (at least three episodes) with or without resistance to therapy

Remarks:

• the diagnosis of major depressive disorder with characteristics of melancholy must be clearly mentioned in the case report form but is not a reason for not being included in the study
• the presence of a recent or older attempted suicide must lead to a careful clinical assessment of the diagnosis of depressive disorder and must be clearly mentioned in the case report form.

Exclusion Criteria:

• Persons not covered by the national Health Insurance Agency
• Psychotic or bipolar disorders
• Severe personality disorders
• cardiovascular disease, proven inflammatory disease and cancer
• persons unable to give their consent personally,
• persons in emergency situations,
• pregnant women,
• breast-feeding women