Segregated neural representation of psychological and somatic-vegetative symptoms in severe major depression.

OBJECTIVE The Beck Depression Inventory (BDI) is probably the most widely used depression scale. It has been suggested that it contains a two-factor structure measuring cognitive-affective (i.e. psychological) and somatic-vegetative depressive symptoms. In this study we aim to evaluate these factors by probing for their neural correlates. METHODS Neural responses evoked by emotional perception, relative to an emotional judgment task, were measured using functional magnetic resonance imaging (fMRI) in 20 medication-free patients with severe MDD. Psychological and somatic-vegetative symptoms were evaluated with the BDI. RESULTS Psychological symptoms correlated with signal changes in the dorsomedial and right ventrolateral prefrontal cortex, while somatic-vegetative symptoms correlated with signal changes in the pre-genual anterior cingulate cortex. CONCLUSIONS These preliminary findings demonstrate segregated neural representation of psychological and somatic-vegetative symptoms of MDD in different cortical regions. Thus, our results indicate that the two-factor structure of the BDI is related to distinct neural correlates.