Decoding Anxiety and/or Depressive Status in Functional Constipation: Insights From Surface‐Based Functional‐Structural Coupling Analysis

BACKGROUND: While patients with functional constipation (FC) are more susceptible to psychiatric issues such as anxiety and depression, the mechanism underlying gut-brain interactions remains elusive. METHODS: This study included 39 FC patients with anxiety/depressive status (FCAD), 32 FC patients without anxiety/depressive status (FCNAD), and 42 healthy controls. Participants underwent clinical examinations and MRI scans, and changes in functional-structural coupling were assessed using surface-based regional homogeneity and cortical thickness. Receiver operating characteristic (ROC) curve analyses were performed to assess the predictive value of these changes. KEY RESULTS: Abnormal coupling changes were exclusively observed in the FCAD group at both global and regional levels, primarily including significantly decreased coupling indices in the left hemisphere and regions within the bilateral visual cortex, left dorsolateral prefrontal cortex, and left posterior cingulate cortex. The FCAD and FCNAD groups were compared and analyzed using ROC curves, which revealed that coupling ratios in the bilateral visual cortex yielded higher predictive accuracy. Specifically, in the 12th sub-region of the left hemisphere, the coupling ratio achieved a sensitivity of 71.9% and a specificity of 74.4%. Meanwhile, the 8th sub-region of the right hemisphere showed a sensitivity of 78.1% and a specificity of 71.8%. CONCLUSIONS AND INFERENCES: These results collectively highlighted asymmetric hemispheric decoupling and impairments in brain regions associated with visual and default mode networks in FCAD patients. These findings offer novel insights into the neurophysiological mechanisms underlying FCAD and may inform the development of more personalized treatment approaches.