FKBP5 and major depressive disorder: For example, in major depressive disorder (MDD) patients who have been exposed to childhood trauma, the risk allele (T) of rs1360780 has been associated with a lower methylation level of FKBP5 in peripheral blood cells, and lower methylation of FKBP5 has been linked to functional as well as to structural alterations in the inferior frontal orbital gyrus (117).