[Abnormal functional connectivity and structure-function coupling of the nucleus accumbens in patients with major depressive disorder].

OBJECTIVES: Major depressive disorder (MDD) is a common affective disorder with complex etiologies and largely unclear pathophysiological mechanisms. The nucleus accumbens (NAc) plays a central role in reward processing, motivational regulation, and emotional integration. Neuroimaging studies suggest that structural and functional abnormalities of the NAc are key contributors to the pathogenesis of MDD. However, the alterations in structure-function coupling (SFC) of the NAc in MDD remain poorly understood. This study aims to systematically investigate abnormal functional connectivity (FC) and SFC of the NAc in patients with MDD by integrating functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) techniques. METHODS: 0.05). CONCLUSIONS: Patients with MDD exhibit enhanced NAc FC, predominantly between the NAc and cognition-related regions such as the inferior parietal lobule and middle frontal gyrus, suggesting imbalance between the reward circuit and cognitive regulatory networks. Moreover, the significantly reduced SFC of bilateral NAc indicated impaired structural-functional integration in MDD. These findings provide potential neuroimaging evidence supporting the involvement of the NAc in the pathophysiological mechanisms of MDD.