Metabolic Reprogramming of Microglia in Neuroinflammation and Depression

Depression is a highly heterogeneous psychiatric disorder with its pathogenesis increasingly linked to dysregulated neuroinflammation. Microglia, as the resident immune cells of the central nervous system (CNS), play a pivotal role in the initiation and progression of the neuroinflammation and the pathophysiology of depression. These cells exhibit a dual role in pro- and anti-inflammatory processes, dynamically regulating immune responses through immunometabolic reprogramming in response to environmental cues. This review elaborates how metabolic remodeling in microglia, particularly within glucose, lipid, and amino acid pathways, drives their polarization toward a pro-inflammatory phenotype. This shift promotes depression pathogenesis via the release of inflammatory factors, disruption of synaptic plasticity, and mediation of neurotoxicity. We further discuss the impact of existing antidepressants on cellular metabolism and highlight the promise and challenges of targeting specific microglial metabolic pathways as a novel therapeutic strategy. This synthesis provides new insights into the immunometabolic mechanisms of depression and outlines directions for developing targeted treatments.