A resting state fMRI study of major depressive disorder with and without anxiety.

BACKGROUND: The neurobiology of the Major depressive disorder (MDD) with anxiety is still unclear. The present study aimed to explore the brain correlates of MDD with and without anxiety in men and women during resting-state fMRI. METHODS: Two hundred and fifty-four patients with MDD (MDD with anxiety, N = 152) and MDD without anxiety, N = 102) and 228 healthy controls (HCs) participated in this study. We compared the fALFF(fractional amplitude of low-frequency fluctuations) and ReHo(regional homogeneity) of ACC(anterior cingulate cortex) and insula among these three groups. We also compared gender difference between MDD with anxiety and MDD without anxiety. RESULTS: We found that the fALFF values within the ACC and insula were significantly lower in MDD with anxiety compared to without anxiety and HCs. However, we did not find differences in ReHo values among the three groups. In women, we found significant differences in fALFF values between MDD with and without anxiety. These differences were not observed in men. CONCLUSIONS: It is possible that MDD with anxiety show less spontaneous BOLD-fMRI signal intensity within the ACC and insula compared to MDD without anxiety, especially in women. The fALFF within the ACC and insula can be a potential biomarker for severe MDD phenotype.

Brain structural alterations in MDD patients with gastrointestinal symptoms: Evidence from the REST-meta-MDD project.

OBJECTIVE: While gastrointestinal (GI) symptoms are very common in patients with major depressive disorder (MDD), few studies have investigated the neural basis behind these symptoms. In this study, we sought to elucidate the neural basis of GI symptoms in MDD patients by analyzing the changes in regional gray matter volume (GMV) and gray matter density (GMD) in brain structure. METHOD: Subjects were recruited from 13 clinical centers and categorized into three groups, each of which is based on the presence or absence of GI symptoms: the GI symptoms group (MDD patients with at least one GI symptom), the non-GI symptoms group (MDD patients without any GI symptoms), and the healthy control group (HCs). Structural magnetic resonance images (MRI) were collected of 335 patients in the GI symptoms group, 149 patients in the non-GI symptoms group, and 446 patients in the healthy control group. The 17-item Hamilton Depression Rating Scale (HAMD-17) was administered to all patients. Correlation analysis and logistic regression analysis were used to determine if there was a correlation between the altered brain regions and the clinical symptoms. RESULTS: There were significantly higher HAMD-17 scores in the GI symptoms group than that of the non-GI symptoms group (P < 0.001). Both GMV and GMD were significant different among the three groups for the bilateral superior temporal gyrus, bilateral middle temporal gyrus, left lingual gyrus, bilateral caudate nucleus, right Fusiform gyrus and bilateral Thalamus (GRF correction, cluster-P < 0.01, voxel-P < 0.001). Compared to the HC group, the GI symptoms group demonstrated increased GMV and GMD in the bilateral superior temporal gyrus, and the non-GI symptoms group demonstrated an increased GMV and GMD in the right superior temporal gyrus, right fusiform gyrus and decreased GMV in the right Caudate nucleus (GRF correction, cluster-P < 0.01, voxel-P < 0.001). Compared to the non-GI symptoms group, the GI symptoms group demonstrated significantly increased GMV and GMD in the bilateral thalamus, as well as decreased GMV in the bilateral superior temporal gyrus and bilateral insula lobe (GRF correction, cluster-P < 0.01, voxel-P < 0.001). While these changed brain areas had significantly association with GI symptoms (P < 0.001), they were not correlated with depressive symptoms (P > 0.05). Risk factors for gastrointestinal symptoms in MDD patients (p < 0.05) included age, increased GMD in the right thalamus, and decreased GMV in the bilateral superior temporal gyrus and left Insula lobe. CONCLUSION: MDD patients with GI symptoms have more severe depressive symptoms. MDD patients with GI symptoms exhibited larger GMV and GMD in the bilateral thalamus, and smaller GMV in the bilateral superior temporal gyrus and bilateral insula lobe that were correlated with GI symptoms, and some of them and age may contribute to the presence of GI symptoms in MDD patients.