2021 Articles

Alterations in Resting-State Functional Activity and Connectivity for Major Depressive Disorder Eating Phenotypes

Piccolo, Mayron; Belleau, Emily; Holsen, Laura M.; Pizzagalli, Diego A.; Javaras, Kristin N.

Background: Major depressive disorder (MDD) is accompanied by changes in appetite and food intake. Identifying neural alterations associated with hyperphagic and hypophagic MDD can yield insight into the mechanisms by which depressed mood impacts appetite and weight changes. Taskbased functional magnetic resonance imaging (fMRI) findings suggest these MDD eating phenotypes are associated with altered reward (e.g., nucleus accumbens, orbitofrontal cortex (OFC)) and interoceptive (e.g., anterior insula) processing. Methods: We used resting state fMRI data to compare fractional amplitude of low-frequency fluctuations (fALFF) and seed-based connectivity (SBC) among hyperphagic (n ¼ 77), hypophagic (n ¼ 66), and euphagic (n ¼ 42) MDD groups and a healthy control group (n ¼ 38). We examined fALFF and SBC in a mask restricted to reward and interoceptive regions and also performed exploratory whole-brain analyses. SBC analyses treated the nucleus accumbens, and regions demonstrating group differences in fALFF (i.e., right lateral OFC and right anterior insula), as seeds. All analyses used Free Threshold Cluster Enhancement. Results: Mask-restricted analyses revealed stronger fALFF in the right lateral OFC, and weaker fALFF in the right anterior insula, for hyperphagic MDD versus healthy controls. We also found weaker SBC between the right lateral OFC and left anterior insula for hyperphagic MDD versus healthy controls. Whole-brain analyses revealed stronger SBC between the lateral OFC and bilateral precentral gyrus for hyperphagic MDD versus healthy controls. Conclusions: Our results suggest that hyperphagic MDD may be associated with altered activity in and connectivity between interoceptive and reward regions.