Abstract
BACKGROUND: Multiple Sclerosis (MS) is often complicated by depression, worsening disability and quality of life. Global depression prevalence in MS is ~27%, but Middle Eastern data are scarce. The neurobiological basis of depression in Relapsing-Remitting Multiple Sclerosis (RRMS) is unclear. OBJECTIVE: This study aimed to assess depression prevalence in Middle Eastern RRMS patients versus controls, evaluate disability using the Expanded Disability Status Scale (EDSS), and explore Magnetic Resonance Imaging (MRI) correlations with depressive symptoms. MATERIAL AND METHODS: In a cross-sectional study (June 2022-June 2023), 105 RRMS patients (mean age 36.2±13.9 years, 83.8% female) and 111 controls (mean age 39.1±10.9 years, 74.8% female) were recruited from Shiraz, Iran MS clinics. Depression was measured using the Beck Depression Inventory (BDI), disability via EDSS, and MRI (1.5-Tesla) analyzed for lesion burden and brain volume using VolBrain. Statistical analyses included t-tests, chi-squared tests, and correlations (P-value<0.05). RESULTS: Depression was more prevalent in RRMS patients (33.3%) than controls (24.5%; P-value=0.15), especially in younger females (P-value=0.02). Mean EDSS was low (1.3-1.4), weakly correlating with right insular cortex plaque volume (r=0.20, P-value=0.03). Depressed patients had higher left limbic (P-value=0.05) and insular cortex (P-value=0.05) plaque burdens, with weak BDI correlations (r=0.19-0.20, P-value<0.04). Brain volume was reduced in depressed patients (P-value=0.09). CONCLUSION: Depression affects one-third of Middle Eastern RRMS patients, exceeding controls. Limbic and insular plaque burdens suggest network dysconnectivity drives depressive symptoms. Routine screening and region-specific interventions are needed.