Research Progress on BDNF and Depression.

Depression is a potentially life-threatening psychiatric disorder that affects the physical and mental health of millions of individuals worldwide. It can manifest at any stage of life, inducing profound emotional despondency, negative cognitions, and, in severe cases, suicidal ideation, often accompanied by physical symptoms, bringing a significant burden on both families and society. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, is widely expressed in the central nervous system (CNS), particularly in regions, such as the hippocampus and cortex. Numerous studies have shown that an imbalance or inadequate conversion of pro-brain-derived neurotrophic factor (proBDNF) into its mature form, mature BDNF (mBDNF), may impair neuronal plasticity, which is crucial to the pathogenesis of depression. This paper provides a comprehensive review of the neurotrophic mechanisms implicated in depression, covering the location, expression, and release of BDNF; the relationship between proBDNF, mBDNF, and depression; and the downstream signaling pathways triggered by BNDF binding to its receptors. This review aims to provide a theoretical foundation for understanding the pathogenesis and clinical treatment of depression.