Functional connectivity of amygdala subregions predicts vulnerability to depression following the COVID-19 pandemic.

Background The amygdala is vital in processing psychological stress and predicting vulnerability or resilience to stress-related disorders. This study aimed to build the link between functional magnetic resonance imaging data obtained before the stress event and the subsequent stress-related depressive symptoms. Methods Neuroimaging data obtained before the coronavirus disease 2019 pandemic from 39 patients with major depressive disorder (MDD) and 61 health controls (HCs) were used in this study. The participants were divided retrospectively into four groups in accordance with the severity of depressive symptoms during the pandemic: remitted patients, non-remitted patients, depressed HCs (HCd) and non-depressed HCs (HCnd). Seed-based resting-state functional connectivity (rsFC) analyses of the amygdala and its subregions, including centromedial (CM), basolateral and superficial (SF), were performed. Results Vulnerability to depression was suggested by the decreased rsFC between the left CM amygdala and the bilateral lingual gyrus in the HCd group compared with the HCnd group, and decreased rsFC of the left CM or right SF amygdala with the precuneus and the postcentral gyrus in the HCd group compared with patients with MDD. No evidence supports the rsFC of the amygdala or its subregions as a biomarker for the resilience of patients with MDD to stress under antidepressant treatment. Limitations Smaller sample size and no longitudinal neuroimaging data. Conclusions Our findings suggest that the rsFC of amygdala subregions may represent a neurobiological marker of vulnerability to depression following stress.