 This study found that serum nerve growth factor, NGF, levels were significantly higher in major depressive disorder, MDD, patients compared to healthy control subjects. This suggests that NGF could serve as a potential biomarker for MDD diagnosis. Further research is needed to investigate the underlying mechanisms, risk factors, disease course, and treatment responses of NGF in MDD. This article was authored by Lubaba Salsabil, Mohammed Sharia, Sada Mohammed Ashraf al-Islam and others.