Investigating the Association Between Water Exchange Across the Blood–Brain Barrier and Depressive Symptoms in Major Depressive Disorder

Motivation: Although previous studies have demonstrated that blood-brain barrier (BBB) dysfunction plays a crucial role in the pathophysiology of depression, current neuroimaging techniques require the use of exogenous contrast agents, which limits their application in major depressive disorder (MDD) patients. Goal(s): This study aims to investigate the relationship between water exchange across the BBB and clinical status in patients with MDD. Approach: We conducted a comparative analysis of apparent exchange rates across the BBB, and assessed their correlations with MADRS and HAMD scores. Results: This study revealed increased water exchange rate across the BBB in patients with MDD, which correlated significantly with symptom severity. Impact: This research advances our understanding of the relationship between blood-brain barrier permeability and major depressive disorder, potentially providing new insights into depression's biological mechanisms and identifying novel therapeutic markers.