NR3C1 and post-traumatic stress disorder: Although lower levels of cortisol in saliva [43], urine [44,45], and hair [46] in patients with PTSD, compared to those without PTSD, have been associated with more persistent traumatic memories and increased PTSD symptoms, the high-risk genotype of the GR gene against PTSD has been associated with increased GR signaling under stress [47], indicating that the GR is activated in patients with PTSD, even those with a low cortisol level.