Vascular Endothelial Growth Factor: a potential diagnostic biomarker for major depression

Despite intense research efforts undertaken by investigators throughout the world over the past half century to identify a specific biomarker for major depressive disorder (MDD), none have so far met the rigorous test of specificity, reliability and reproducibility. Vascular Endothelial Growth Factor (VEGF) has been implicated in the neurotrophic model of depression and several studies have assessed VEGF levels in depressed patients. The results have been discrepant largely due to design and assay differences among studies. The aim of this study was to assess plasma VEGF levels in a cohort of MDD subjects prior to treatment with psychotropic medication and compare them to those of healthy control (HC) subjects. Prospective study participants underwent extensive medical and psychiatric assessments before they were enrolled. Plasma concentrations of VEGF were measured by the technique marketed by Randox Technologies. The mean baseline VEGF for the healthy and depressed groups was 5.91 pg/ml (SD: 3.04) and 10.51 pg/ml (SD: 9.04), respectively, and this difference was statistically significant (p = 0.001). We detected a very low univariate relationship between VEGF and demographic and clinical variables. Using the Optimal Data Analysis a cut score of 6.64 pg/ml for baseline plasma VEGF distinguished depressed from healthy subjects with a 63% overall accuracy. We conclude these results support a role of plasma VEGF as a useful biomarker of depression that can be measured with a routine blood draw at the point of service. The specificity of this potential biomarker must be confirmed in studies that include other psychiatric disease entities.