An exploratory study of altered regional homogeneity in Parkinson’s disease with depression

Abstract Depression is a prevalent non-motor symptom in Parkinson's disease (PD) with unclear pathogenesis and lacking established biomarkers. This study investigated depression in PD (DPD) using Regional Homogeneity (ReHo) analysis of resting-state functional magnetic resonance imaging (rs-fMRI). We enrolled 23 DPD patients, 24 non-depressed PD (NDPD) patients, and 20 healthy controls (HC). Results demonstrated that DPD patients exhibited increased ReHo in the left inferior temporal gyrus (ITG) and decreased ReHo in the right middle frontal gyrus (MFG), left insula, and left hippocampus compared to NDPD patients. These ReHo alterations significantly correlated with HAMD scores in PD patients. ROC analysis indicated that decreased ReHo in the left insula and left hippocampus demonstrates potential as a neuroimaging biomarker for distinguishing DPD (AUC = 0.8062). Distinct ReHo patterns involving temporal, frontal, and limbic regions may underlie DPD, with left insular and hippocampal changes showing diagnostic biomarker potential.