Genetic determinants of circulating VEGF levels in major depressive disorder and electroconvulsive therapy response.

Alterations in peripheral vascular endothelial growth factor (VEGF) levels were observed in major depressive disorder and relative treatments and were shown to be influenced by genetic variants. The study objective was to explore, at a genome-wide level, possible interplaying effects between the genetic background and major depressive disorder in regulating VEGF levels. Moreover, we aimed to investigate the association between these variants and response to electroconvulsive therapy. A genome-wide association study was carried out both on controls and patients with major depressive disorder (n= 145;n= 121) in correlation with serum VEGF levels determined by ELISA. Five SNPs not included in SNP arrays were additionally genotyped. Seventy-one patients with treatment-resistant depression underwent electroconvulsive therapy and were evaluated as responders/nonresponders. An association between VEGF levels and a locus in 6p21.1, downstream theVEGFgene, was evidenced both in controls (best SNP: FDR-correctedp= 2.4 x 10(-5)) and in patients with major depressive disorder (best SNP: FDR-correctedp= 2.6 x 10(-3)). The alleles associated with lower VEGF concentrations in patients were also associated with nonresponse to electroconvulsive therapy (p= .01). These results confirm a role of SNPs in 6p21.1 locus as major influencers of circulating VEGF levels also in patients affected by major depressive disorder and indicate a possible implication in response to electroconvulsive therapy.