Reduced left subgenual anterior cingulate cortical activity during withdrawal-related emotions in melancholic...

Research regarding the neurocircuitry in mood disorders suggests an important role for affective information processing of the subgenual part of the anterior cingulate cortex (Cg25: Brodmann area 25).

In this study, we focused on Cg25 neuronal responses in depressed females using a paradigm in which emotions are elicited without explicit cognitive control, relying on the salient nature of the mood inducing stimuli eliciting approach-related emotions (like happiness) or withdrawal-related emotions (like disgust).

Twelve treatment-resistant melancholic depressed women and 12 healthy female control subjects were asked to passively view blocks of emotionally valenced baby faces while undergoing functional magnetic resonance imaging (fMRI).

Compared to the healthy females, the depressed patients displayed significantly higher bilateral Cg25 neuronal activities in both emotional conditions. In melancholically depressed women, we found significantly less left-sided than right-sided Cg25 neuronal activity during the withdrawal-related emotions, while right-sided Cg25 activity was comparable for both emotional responses.

Our results indicate that in depressed women the left Cg25 modulates intense visceral emotional responses to aversive visual stimuli. This could help explain why the left Cg25 provides a valid target region for antidepressant treatment strategies in unipolar melancholic depression.