[Severe depression : pharmacological treatments].

Depression is a common illness with a large clinical phenotype, and clinicians have numerous guidelines to treat this disorder : many antidepressant drugs are available with different pharmacological profiles and stepped strategies are proposed to obtain a remission. It exists a relationship between baseline depression symptom severity and treatment response and patient with higher levels of severity received significantly more intervention visits, more months of antidepressant treatment and more antidepressant trials, but there is not accepted and consensual definition for severe depression. By using cut-off scores on rating scales severe depression is at one extreme of a continuum of severity (but scales which serve for quantifying the intensity of the depression with thresholds present an interest and also limits, in the current practice, they are rarely used), in the other hand some symptoms contributes to severity (psychotics features, suicidal ideation), evolution and prognosis is a part of severity too (recurrences, chronicity), severe depression can influence a somatic pathology contributing to severity (could be considered itself as a major risk factor) and have an impact on treatment outcome, finally by its role on morbi-mortality and handicap, depression is often a severe disorder. So, concerning the therapeutic choices, there are few data to choose specific options because the concept of severity in the depression is not still clearly defined in studies and few randomized contolled studies have been done in this indication and adapted to different modality of the severity expression. Symptom-free remission is a goal for treatment in severe depression, but complications have to be considered in medication algorithms. In this paper, we review the modalities of prescription of antidepressants according to these differences of the severity in depression.