Thus, the pathophysiology of PTSD involves several neurotransmitters, including the noradrenergic, serotonergic, endogenous cannabinoid, and opioid systems, as well as the hypothalamic–pituitary adrenal axis and the release of the corticotropin-releasing factor, which are systems involved in other psychiatric conditions, such as mood or anxiety disorders [4]. This evidence concerns the gene CRH and post-traumatic stress disorder.