Differential Role of Fusiform Gyrus Coupling in Depressive and Anxiety Symptoms During Emotion Perception

Abstract

Background: Anxiety and depression co-occur; the neural substrates of shared and unique components of these symptoms are not understood. Given emotional alterations in internalizing disorders, we hypothesized that function of regions associated with emotion processing/regulation, including the anterior cingulate cortex(ACC), amygdala, and fusiform gyrus(FG), would differentiate these symptoms.

Methods: Forty-three adults with depression completed an emotional fMRI task and the Hamilton Depression and Anxiety Scales. We transformed these scales to examine two orthogonal components, one representing internalizing symptom severity and the other the type of internalizing symptoms (anxiety vs depression). We extracted BOLD signal from FG subregions, ACC, and amygdala and performed gPPI analyses to assess relationships between symptoms and brain function.

Results: Type of internalizing symptoms was associated with FG3-FG1 coupling(F=8.14,p=0.007). More coupling was associated with a higher concentration of depression, demonstrating that intra-fusiform coupling is differentially associated with internalizing symptom type(anxiety vs depression). We found an interaction between task condition and internalizing symptoms and dorsal(F=4.51,p=0.014) and rostral ACC activity(F=4.27,p=0.012). Post hoc comparisons revealed less activity was associated with greater symptom severity during emotion regulation.

Conclusions: Functional coupling differences during emotional processing are associated with depressive relative to anxiety symptoms, and internalizing symptom severity. These findings could inform future treatments for depression.