Reduced Hippocampal Volumes Associated With the Long Variant of theSerotonin Transporter Polymorphism in Major Depression

Abstract

One of the major biological substrates in the pathogenesis of majordepression is the serotonergic system.¹ Serotoninis a widespread neurotransmitter in the central nervous system. Serotonergicneurons are mainly found in different raphe nuclei, from which they projectto numerous brain regions such as cortical areas, the hippocampus, and thebasal ganglia.² The fine-tuning of serotoninneurotransmission seems to be critically influenced by the serotonin transporter(5-HTT) via clearing synaptic serotonin.