Lung cancer remains a leading cause of cancer-related mortality worldwide. Depression, highly prevalent in lung cancer patients, not only impairs quality of life but also adversely affects disease pro Show more
Lung cancer remains a leading cause of cancer-related mortality worldwide. Depression, highly prevalent in lung cancer patients, not only impairs quality of life but also adversely affects disease progression and treatment outcomes through complex biological pathways. Previously considered merely a psychological reaction, depression is now recognized as sharing bidirectional pathophysiological interactions with lung cancer. This narrative review comprehensively reviews current evidence on the molecular mechanisms linking depression to lung cancer progression, with a focus on dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), cytokine-mediated inflammation, and the lung-brain axis involving BDNF/TrkB signaling. We also discuss the potential therapeutic implications of antidepressants, including their effects on apoptosis, autophagy, and immune modulation. Key findings suggest that depression promotes tumor progression via chronic stress pathways, while antidepressants may counter these effects through multiple mechanisms. Understanding these pathways may inform integrated treatment strategies and improve prognosis in lung cancer with comorbid depression. Show less
Major depressive disorder is associated with deficits in hippocampal synaptic plasticity that depend on brain-derived neurotrophic factor (BDNF) release from both axonal and dendritic compartments. An Show more
Major depressive disorder is associated with deficits in hippocampal synaptic plasticity that depend on brain-derived neurotrophic factor (BDNF) release from both axonal and dendritic compartments. Antidepressant efficacy requires enhanced BDNF signaling, thought to be mediated by drug-induced BDNF release from postsynaptic dendritic spines. Here, we show that fast-acting antidepressants rapidly trigger BDNF secretion from presynaptic terminals in hippocampal area CA3. At antidepressant-relevant concentrations, ketamine and its metabolite (2R,6R)-hydroxynorketamine (HNK) induced BDNF release within minutes from mossy fiber terminals of dentate granule neurons in rat hippocampal cultures, with no detectable secretion from dendritic spines. This antidepressant-evoked BDNF release required presynaptic NMDA receptors (preNMDARs). Conditional genetic deletion of preNMDARs from granule neurons abolished ketamine- and HNK-induced BDNF exocytosis in acute mouse hippocampal slices, establishing a presynaptic receptor mechanism for antidepressant-induced neurotrophin release. In CA3 pyramidal neurons that receive mossy fiber input, both compounds induced rapid remodeling of dendritic spines, resulting in increased spine density. Together, these findings identify presynaptic terminals as a previously unrecognized source of antidepressant-evoked BDNF release and establish a new cellular mechanism for the rapid synaptic effects of fast-acting antidepressants. Show less