Increased default mode network activation in depression and social anxiety during upward social comparison

Abstract

Social comparisons are a core feature of human life. Theories posit that social comparisons play a critical role in depression and social anxiety triggering negative evaluations about the self, as well as negative emotions. We investigated the neural basis of social comparisons in participants with major depression and/or social anxiety (MD-SA, n = 56) and healthy controls (n = 47) using functional magnetic resonance imaging. While being scanned participants performed a social comparison task, during which they received feedback about their performance and the performance of a coplayer. Upward social comparisons (being worse than the coplayer) elicited high levels of negative emotions (shame, guilt, and nervousness) across participants, with this effect being enhanced in the MD-SA group. Notably, during upward comparison the MD-SA group showed greater activation than the control group in regions of the default mode network (DMN). Specifically, for upward comparison MD-SA participants demonstrated increased activation in the dorsomedial prefrontal cortex and reduced deactivation in the posteromedial cortex, regions linked to self-referential processing, inferences about other people's thoughts, and rumination. Findings suggest that people with depression and social anxiety react to upward comparisons with a more negative emotional response, which may be linked to introspective processes related to the DMN.

Keywords: depression; fMRI; social anxiety; social comparison.

Figure 1.

(a) The social comparison task. rt, reaction time; s, seconds. (b) Emotional responses to the social comparison task outcomes. RR: “Self_Right, Other_Right”; RW: “Self_Right, Other Wrong”; WR: “Self_Wrong, Other_Right”; WW: “Self_Wrong, Other Wrong’’. Error bars denote standard error of the mean. Asterisks denote significant between group differences.

Figure 2.

Neural responses related to downward comparison. Across all subjects (a) as well as in the control (b) and MD-SA (c) groups, the contrast for downward comparison elicited activations across the mPFC, dlPFC, posteromedial cortex, thalamus, caudate, and bilateral insula.

Figure 3.

Neural responses related to upward comparison. For the contrast upward comparison greater than the even wrong outcome, (a) across all subjects activations were observed in the upper dmPFC and insula; (c) the MD-SA group showed activation in the dmPFC, (b) while controls did not show this activation. For the opposite contrast (the even wrong outcome greater than upward comparison), activations are shown across (d) all subjects; (e) controls; and (f) MD-SA group. Controls showed activation in the vmPFC and posteromedial cortex (e), while the MD-SA group did not show these activations (f).

Figure 4.

(a) Between group differences in neural responses related to upward comparison. In the bar graphs, the Y-axis represents the mean value of parameter estimates across voxels within a sphere diameter of 10 mm centered at peak coordinates (b) (−10, −42, 46), (c) (−4, −56, 14), and (d) (6, 56, 20). Error bars denote standard error of the mean.