SLC6A15 and major depressive disorder: In an investigation of the hypothalamic-pituitary-adrenocortical (HPA) axis abnormalities in MDD, Schuhmacher et al. have reported that one single nucleotide polymorphism (SNP) of SLC6A15 (rs1545843) is associated with alterations in HPA axis activity, memory, and attention in patients with MDD [12].