A clinical randomized controlled study showed that during 24 weeks of treatment with escitalopram in patients with severe depression, circulating endothelial cells (CECs), vWF, and VCAM-1 was decreased, endothelial nitric oxide synthase was gradually restored to an average level, and reactive oxygen species production was reduced (Lopez-Vilchez et al., 2016). This evidence concerns the gene NOS3 and major depressive disorder.