Background <p>Low back pain (LBP) is a prevalent health issue with a significant global burden, particularly chronic low back pain, which is especially debilitating. It often accompanied by additional challenges such as depression and disability. Brain-derived Neurotrophic Factor (BDNF) has emerged as a potential biomarker for neuropathic pain and depression. This study explores the relationship between salivary BDNF (sBDNF) levels and LBP, with the aim of enhancing our understanding of the condition to improve pain management.</p> Methodology <p>This cross-sectional observational study assessed sBDNF levels across three groups: individuals with acute low back pain, chronic low back pain, and healthy controls (no pain). The study also evaluated the correlation between sBDNF levels and factors such as depression, disability, body mass index (BMI), exercise, and lumbar degenerative changes.</p> Results <p>sBDNF levels were significantly lower in the chronic group compared to the acute and the healthy controls (<i>p</i> &lt; 0.001). The chronic pain group exhibited higher depression scores and disability levels compared to the acute and healthy groups. A significant negative correlation was found between BDNF levels and depression (<i>p</i> &lt; 0.0001), while higher BDNF levels were associated with lower disability (<i>p</i> &lt; 0.0001). Additionally, BDNF levels showed a negative correlation with body mass index (BMI) (<i>p</i> &lt; 0.05).</p> Conclusion <p>Salivary BDNF levels vary across LBP conditions, with lower levels in Chronic low back pain. BDNF levels correlate with depression, disability, and BMI. These findings suggest that salivary BDNF levels may serve as a potential biomarker to guide future personalized approaches in chronic pain management, though further longitudinal validation is needed.</p>