Abnormal spontaneous brain activity in patients with generalized anxiety disorder revealed by resting-state functional MRI

This study aimed to examine the spontaneous hemodynamic fluctuations and the dysfunctional brain regions in patients with generalized anxiety disorder (GAD) using resting-state functional MRI. Previous studies have demonstrated some neural networks that are different in this patient group compared with healthy controls. However, there is still a need for precise anatomical localization of the aberrantly operating networks. We used resting-state functional MRI to measure the hemodynamic fluctuations in 31 GAD patients and 31 control participants matched for sex, age, and education. On the basis of the hemodynamic fluctuations, we calculated regional homogeneity (ReHo) for our comparisons as this measure reflects coherent fluctuations in adjacently located brain regions. The Hamilton Anxiety Rating Scale was used to assess symptom severity of the GAD patients. There were no significant differences with respect to age, sex, handedness, and education. However, compared with controls, GAD patients showed higher Hamilton Anxiety Rating Scale scores (16.90±1.94, P<0.05). We identified decreased ReHo measures in the right inferior frontal gyrus and the left caudate nucleus in the GAD group compared with the healthy controls. In addition, we found increased ReHo measures within the left cingulate gyrus. This study further complements the network characteristics in anxiety patients and presents new and more accurate anatomical positioning about GAD patients.