Network localization of brain structural and functional abnormalities in association with rumination.

BACKGROUND

Rumination, a recurrent and passive focus of thoughts on depressed mood and its possible causes and consequences, constitutes a characteristic feature of major depressive disorder (MDD). Despite considerable recent efforts to map neuropsychiatric symptoms to specific brain networks, little attention has been paid to network localization of rumination.

METHODS

We initially conducted a systematic review of 49 published neuroimaging studies to identify rumination-related brain structural and functional alterations. Subsequently, by integrating these affected brain locations with large-scale discovery (1113 healthy individuals) and validation (1093 healthy individuals and 255 MDD patients) resting-state functional magnetic resonance imaging datasets, we applied novel functional connectivity network mapping to construct 3 rumination networks corresponding to different imaging modalities.

RESULTS

The rumination gray matter volume abnormality network comprised widely distributed brain regions, primarily involving the ventral attention, subcortical, frontoparietal, limbic, somatomotor, and dorsal attention networks. The resting-state activity abnormality network mainly implicated the default network. The task-induced activation abnormality network was similar to the gray matter volume abnormality network, but the spatial extent was much smaller, chiefly involving the ventral attention and somatomotor networks.

CONCLUSION

Our findings help establish an integrative framework that may explain the neurobiology of rumination from a network perspective, laying the foundation for developing reliable biomarkers and targeted treatments for rumination.