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.