The PCSK9 Protein Is Not Necessarily a Risk Factor for Major Depressive Disorder

Introduction: Major depressive disorder (MDD) is one of the common psychiatric disorders that is characterized by abnormal neurobiological responses. Proprotein convertase subtilisin/kexin 9 (PCSK9) is important in cholesterol homeostasis. Methods: This study aimed to investigate PCSK9 levels and oxidative stress with MDD disease. The study included 30 patients with MDD and 30 healthy controls. Their blood samples were collected in sterile tubes, and the serum PCSK9 concentration, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activity were determined by ELISA kits. Total antioxidant capacity (TAC), total oxidant status (TOS), malondialdehyde (MDA), and copper concentration were determined manually. There was a significant increase in PCSK9 levels in the patient group (P 0.05).  Results: The receiver operating characteristic (ROC) curve with a sensitivity of 57% and specificity of 52% was 0.928 (95% CI, 0.86-0.996) for PCSK9 in the patient group (P 0.001). It was found that MDA (P=0.036) level was higher in the MDD group, but TAC (P=0.445) level, SOD (P=0.148), GPx (P=0.019) activities, and copper concentration were lower in the patient group compared with the control group. Conclusion: The study results confirm the relationship between oxidative stress and MDD and also suggest a link between PCSK9 and MDD disease.