[Severe depression : functional neuroanatomy]

Depression is a severe disorder to which some individuals are more vulnerable than others. The study of the neurocognitive basis of the vulnerability to depression is, therefore, of major importance. Several neuroimaging studies have shown the persistence of brain dysfunctions in remitted patients. At the neuroanatomic level, alterations of the amygdala, ventral, medial and dorsolateral prefrontal cortices, cingulate gyrus, hippocampus and basal nuclei, and their connections, have been reported. These impairments have been linked to altered cognitive and emotional processes including a higher sensitivity to specific environmental stimuli, impairment in emotional regulation and diminished working memory or inhibition. Moreover, other studies suggest that these dysfunctions should be distinguished from those related to the vulnerability to suicidal behavior, which should be considered as a specific pathological entity. Finally, preliminary studies have underlined the genetic modulation and the influence of early traumatic events on brain activations, which underscore the developmental features of these alterations. These findings open the door to new treatments.