Abnormal functional connectivity in resting state contributes to the weaker emotional sensitivity to reward in depression

Introduction Depression is one of the most prevalent mental diseases characterized by distortions in the affective sphere. By using resting-state functional magnetic resonance imaging (rs-fMRI) technique, the current study aimed to investigate neural mechanisms associated with emotional sensitivity to reward, which represented the variation of emotional responsiveness as the degree of reward changing in individuals with depressive symptoms.Methods We recruited 28 participants in elevated depressive symptoms (LD) group and 28 demographic-matched participants in low depressive symptoms (ED) group. After the rs-fMRI scan, participants were asked to complete a sequential risk-taking task, in which they might encounter both reward and loss.Results The resting-state functional connectivity (rs-FC) between ventral striatum (VS) and inferior frontal gyrus (IFG) was associated with the emotional sensitivity to reward in LD group. Compared with LD group, participants in ED group showed weaker emotional sensitivity to reward and stronger rs-FC between VS and prefrontal regions.Conclusions The current study highlighted that the functional connectivity between VS and IFG in the resting state was related to the emotional sensitivity to reward in individuals with low depressive symptoms. However, individuals with elevated depressive symptoms exhibited altered functional connectivity between VS and IFG in the resting state, which might contribute to their weaker emotional sensitivity to reward.