ABSTRACT
BACKGROUND: Major depressive disorder (MDD) is a highly prevalent and burdening mental illness. Approximately 30% of the major depressive episodes (MDE) are classified as therapy-refractory. Further knowledge of the pathophysiological mechanisms underlying MDD and predictive biomarkers are needed to improve treatment options. METHODS: Serum lipid levels were compared between patients with a current MDE (nâ¯=â¯130) or remitted MDD (nâ¯=â¯39) and healthy control subjects (nâ¯=â¯61) and associated with the severity (17-item Hamilton Depression Rating Scale [HAMD] scores) and the prospective course of depression (direct follow-up of at median 20â¯days post-inclusion). RESULTS: We found higher levels of LDL cholesterol (152.5 vs. 134.0â¯mg/dl, Uâ¯=â¯3021, Pâ¯=â¯0.008) and LDL/HDL ratio (2.82 vs. 2.21, Uâ¯=â¯2912, Pâ¯=â¯0.003) in patients with a current MDE than in healthy control subjects. In patients with a current MDE, higher HAMD scores correlated also with higher values of triglycerides (ρâ¯=â¯0.213, Pâ¯=â¯0.015), total cholesterol (ρâ¯=â¯0.199, Pâ¯=â¯0.023), LDL cholesterol (ρâ¯=â¯0.224, Pâ¯=â¯0.010), and LDL/HDL ratio (ρâ¯=â¯0.196, Pâ¯=â¯0.026). Moreover, higher total cholesterol (ρâ¯=â¯-0.233, Pâ¯=â¯0.010), LDL cholesterol (ρâ¯=â¯-0.235, Pâ¯=â¯0.010), and LDL/HDL ratio (ρâ¯=â¯-0.199, Pâ¯=â¯0.029) were associated with a stronger decline in HAMD score between study inclusion and direct follow-up. LIMITATIONS: We employed an associational study design, performed only a short-term follow-up, and excluded suicidal study subjects. CONCLUSIONS: Serum lipid levels are associated with depression per se, the depression severity, and the prospective 3-week course. These observations build the basis for future investigations on individualized lipid metabolism-related treatment strategies in depressed patients.