Differences in the neural correlates of affective responses in depressed and healthy women

Abstract

We aimed to characterize the extent to which there were differences in neural activation between female participants who were diagnosed with or without depression while viewing negative and neutral imagery. The study enrolled 105 medication-free, right-handed female participants between 17 and 63 years who met criteria for current Major Depressive Disorder (n=47) or no prior psychiatric diagnoses (n=58). All participants completed a clinical assessment and underwent a functional Magnetic Resonance Imaging (fMRI) scan while responding to an implicit affect task that required them to identify the location of ideographs embedded in one of four corners of each valenced image. When unpleasant (termed negative) stimuli were presented, depressed relative to healthy participants showed significantly decreased activation of the left amygdala and right Inferior Parietal Lobe (IPL). When activation was assessed during the negative versus neutral condition, depressed relative to healthy participants showed significantly increased activation in the Anterior Cingulate Cortex (ACC) and the left IPL. Notably, within-group analyses of healthy participants under the negative condition showed that depressive severity was positively correlated with activation in the left amygdala and left IPL. Our findings suggest that depression influences bottom-up and top-down processing of unpleasant information.

Keywords: Affect; Amygdala; Anterior cingulate cortex; Depression; Inferior parietal lobe; Women.