Disruption of brain regional homogeneity and functional connectivity in patients with generalized anxiety disorder: A resting-state fMRI study.

Generalized anxiety disorder (GAD) is a common psychiatric condition characterized by chronic excessive worry and abnormal neural circuitry dynamics, as identified by functional magnetic resonance imaging (fMRI). This study employs regional homogeneity (ReHo) and seed-based functional connectivity (FC) analyses to investigate intrinsic brain activity patterns in GAD, offering new neuroimaging insights into its pathophysiology. We enrolled 36 GAD patients and 33 healthy controls (HCs), who underwent resting-state fMRI and clinical assessments. ReHo differences between groups were analyzed, followed by FC analysis using altered ReHo regions as seeds. Correlations between ReHo/FC metrics, cognitive performance, and clinical parameters were examined. Patients with GAD exhibited decreased ReHo in the right cingulate gyrus and left precentral gyrus. FC analysis revealed increased coupling between the left precentral gyrus and the inferior parietal lobule (An integral component of the default mode network [DMN]), while connectivity between the left precentral and postcentral gyri was diminished. These FC changes were clinically relevant: precentral-postcentral connectivity positively correlated with illness duration, while precentral- inferior parietal lobule connectivity showed a negative association with Hamilton Anxiety Rating Scale scores. Neuroimaging studies reveal that GAD is linked to specific functional abnormalities in the cingulate and precentral gyri, as well as altered connectivity within the sensorimotor network and between the sensorimotor network and inferior parietal lobule (An integral component of the DMN). However, large-scale longitudinal studies incorporating multi-modal neuroimaging approaches are needed to establish whether these neural alterations represent pathophysiological mechanisms underlying GAD.