Disrupted regional homogeneity in treatment-resistant depression: a resting-state fMRI study.

BACKGROUND Using a newly developed regional homogeneity (ReHo) approach, we were to explore the features of brain activity in patients with treatment-resistant depression (TRD) in resting state, and further to examine the relationship between abnormal brain activity in TRD patients and specific symptom factors derived from ratings on the Hamilton Rating Scale for Depression (HRSD). METHODS 24 patients with TRD and 19 gender-, age-, and education-matched healthy subjects participated in the fMRI scans. RESULTS 1. Compared with healthy controls, decreased ReHo were found in TRD patients in the left insula, superior temporal gyrus, inferior frontal gyrus, lingual gyrus and cerebellumanterior lobe (culmen) (p<0.05, corrected). 2. Compared with healthy controls, increased ReHo were found in the left superior temporal gyrus, cerebellum posterior lobe (tuber), cerebellum anterior lobe (culmen), the right cerebellar tonsil and bilateral fusiform gyrus (p<0.05, corrected). 3. There was no correlation between the ReHo values in any brain region detected in our study and the patients' age, years of education, illness duration, HRSD total score and its symptom factors. LIMITATION The influence of antidepressants to the brain activity in TRD patients was not fully eliminated. CONCLUSIONS The pathogenesis of TRD may be attributed to abnormal neural activity in multiple brain regions.