Association between anhedonia and ventral striatum-MPFC connectivity in first-episode, treatment-naïve major depressive disorder.

BACKGROUND

Evidence demonstrated that frontostriatal disruption may result in anhedonia in major depressive disorder (MDD). However, limited research examined the correlations of frontostriatal connectivity and anhedonia, especially in first-episode, treatment-naïve major depressive disorder.

METHOD

Resting-state functional magnetic resonance imaging (rs-fMRI) was obtained from 44 first-episode, treatment-naïve young adult patients with MDD and 50 healthy controls (HCs). Seed-based functional connectivity and Granger causality analysis were computed to examine, respectively, functional connectivity and directional effective connectivity related to frontostriatal circuit. Association between functional and effective connectivity of frontostriatal and severity of anhedonia was investigated.

RESULTS

MDD patients showed higher levels of anhedonia than healthy controls. Compare to healthy individuals, subjects with MDD exhibited simultaneously increased functional and effective connectivity in ventral striatum and medial prefrontal cortex (MPFC). Additionally, we observed decreased functional connectivity between superior ventral striatum and precuneus, and reduced effective connectivity from inferior parietal lobule to ventral striatum in patients with MDD. Correlation analysis manifested functional connectivity between superior ventral striatum and MPFC was positively correlated with severity of anhedonia in MDD group.

CONCLUSIONS

Our observation verified dysfunction in functional and effective connectivity between ventral striatum and MPFC in patients with major depression. Our study suggested that anhedonia was closely linked to altered ventral striatum and MPFC connectivity, highlighting the importance of ventral striatum-MPFC connectivity in pathophysiological mechanism of MDD.