In a recent study in Biological Psychiatry, Levy-Gigi et al. found that a 12 weekly 90-mins cognitive behavioral therapy (CBT) treatment in individuals with posttraumatic stress disorder (PTSD) is associated with an increase in hippocampal volume and expression of glucocorticoid receptor genes, known as FKBP5 (Levy-Gigi et al., 2013). This evidence concerns the gene FKBP5 and post-traumatic stress disorder.