HTR2A and post-traumatic stress disorder: Recently, human serotonin 2a receptor agonists (e.g. LSD, ayahuasca/DMT, psilocybin/psilocin, peyote/mescaline, 5-MeO-DMT) have shown incredible potential for treating a wide variety of the world’s most debilitating, intra­ctable, and costly health problems, including anxiety, depression, addiction, post-traumatic stress disorder (PTSD) and inflammation (Johnson & Griffiths, 2017 ▸; Carhart-Harris & Goodwin, 2017 ▸).