Differential effects of serotonergic and noradrenergic antidepressants on brain activity during a cognitive control task and neurofunctional prediction of treatment outcome in patients with depression.

BACKGROUND We investigated the differential effects of serotonergic and noradrenergic antidepressants on brain activation in patients with major depressive disorder during a Stroop task. We predicted that pretreatment hyperactivity in the rostral anterior cingulate cortex would predict better treatment outcomes. METHODS In total, 20 patients underwent naturalistic open-label clinical treatment with citalopram (n = 12) or reboxetine (n = 8). We performed functional magnetic resonance imaging at baseline and after 6 weeks of treatment. RESULTS There were no significant group differences in clinical characteristics, treatment outcomes or baseline fMRI activations. The group by time interaction revealed significant voxels in the right amygdala-hippocampus complex (p < 0.05, family-wise error corrected by use of the bilateral amygdala and hippocampus mask image as a small volume), indicating a posttreatment blood oxygen level- dependent signal decrease in the citalopram group. Pretreatment hyperactivity in the rostral anterior cingulate cortex was not related to symptom improvement. LIMITATIONS Our study was a nonrandomized clinical trial. CONCLUSION These results indicate that serotonergic and noradrenergic antidepressants have a differential effect on brain activity, especially in the amygdala and hippocampus.