Posttraumatic stress disorder (PTSD) can occur in a subset of individuals exposed to extreme traumatic events [145], and has a lifetime incidence of ~9–15% [146, 147], and an estimated genetic inheritance of ~30% [148]. Susceptibility genes for PTSD have not yet been identified, but to date the number of individuals screened is low, while the few genetic studies that have been performed mainly focussed on key candidate genes, including BDNF, neuropeptide Y (NPY; 7p15.1), the glucocorticoid receptor (NR3C1; 5q31.3), and components of the serotonin and dopamine pathways [149-153].
