Mechanistic Links Between Depression and Lung Cancer Progression: Therapeutic Implications of Antidepressants

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.