{Reference Type}: Journal Article {Title}: Substance P's Impact on Chronic Pain and Psychiatric Conditions-A Narrative Review. {Author}: Humes C;Sic A;Knezevic NN; {Journal}: Int J Mol Sci {Volume}: 25 {Issue}: 11 {Year}: 2024 May 28 {Factor}: 6.208 {DOI}: 10.3390/ijms25115905 {Abstract}: Substance P (SP) plays a crucial role in pain modulation, with significant implications for major depressive disorder (MDD), anxiety disorders, and post-traumatic stress disorder (PTSD). Elevated SP levels are linked to heightened pain sensitivity and various psychiatric conditions, spurring interest in potential therapeutic interventions. In chronic pain, commonly associated with MDD and anxiety disorders, SP emerges as a key mediator in pain and emotional regulation. This review examines SP's impact on pain perception and its contributions to MDD, anxiety disorders, and PTSD. The association of SP with increased pain sensitivity and chronic pain conditions underscores its importance in pain modulation. Additionally, SP influences the pathophysiology of MDD, anxiety disorders, and PTSD, highlighting its potential as a therapeutic target. Understanding SP's diverse effects provides valuable insights into the mechanisms underlying these psychiatric disorders and their treatment. Further research is essential to explore SP modulation in psychiatric disorders and develop more effective treatment strategies.