FKBP5 and post-traumatic stress disorder: The complex nature of the FKBP5-mediated stress response, especially when taking different stressors into account, is also apparent from two studies investigating FKBP5 × childhood trauma: whereas homozygous rs1360780 T allele carriers who experienced a traumatic childhood event were at the greatest risk for depression or PTSD, respectively, non-traumatized TT homozygotes were at lower risk compared to C allele carriers (Xie et al. 2010; Zimmermann et al. 2011).