Altered regional homogeneity in patients with somatic depression: A resting-state fMRI study

Abstract Background Somatic symptoms are common among patients with major depressive disorder (MDD), and are known to negatively impact the course and severity of the disease. Although previous studies have attempted to explore the neuropathology of MDD, little is known regarding the neural basis of somatic symptoms in MDD. Methods Resting-state functional magnetic resonance images of 28 MDD patients with somatic symptoms (somatic depression, SD), 30 patients without somatic symptoms (non-somatic depression, NSD) and 30 healthy controls (HC) were obtained. We investigated the neural basis of MDD with somatic symptoms based on the measure of regional homogeneity (ReHo). We also investigated whether the altered regional homogeneity may be correlated to any clinical features of depression. These comparison were also carried out in female and male subjects respectively. Results The SD exhibited higher ReHo in the bilateral parahippocampus and left lingual gyrus than HC, as well as lower ReHo in the right frontal gyrus. Relative to NSD, the SD exhibited lower ReHo in the right middle frontal gyrus and left precentral gyrus. Furthermore, in the SD, ReHo in the left precentral gyrus was positively correlated with cognitive factor scores of the HAMD-17. In female subjects, SD exhibited increased ReHo in the right STG and decreased ReHo in the right MFG, relative to women of the NSD group. Conclusions Our preliminary findings indicated that abnormal ReHo in the frontal and temporal regions may play an important role in the neural basis of somatic depression.