The Depressed Brain's Connectome: A Systematic Review of Brain Topological Alterations Through Graph Metrics

Major Depressive Disorder (MDD) is a prevalent and debilitating mood disorder characterized by persistent sadness, anhedonia, and cognitive impairments. This systematic review aims to synthesize current literature on brain network alterations in MDD through the lens of graph theory analysis. We conducted a comprehensive search across multiple databases, identifying studies that examined the structural and functional connectivity of the brain in unmedicated adults diagnosed with MDD. Our findings reveal significant disruptions in the connectivity of key brain region and alterations in topological organization, highlighting the importance of evaluating the brain's global network properties. By focusing on whole-brain connectivity rather than isolated regions, this review provides a more integrated understanding of MDD's neurobiological underpinnings, paving the way for future research and potential therapeutic advancements.