Smaller Hippocampus Volume Is Associated with Short Variant of 5-HTTLPR Polymorphism in Medication-Free Major Depressive Disorder Patients

Abstract

The 5-HTTLPR polymorphism has an effect on hippocampal volumes of depressed patients, which is apparent only in S/S genotype. It seems that decreased neurogenesis by effects of reduced serotoninergic transmission may be responsible for smaller hippocampal volumes observed in S/S homozygous depressed patients.