Since the early 1970s, a vast majority of psychedelic substances have been classified as having no recognized medical value and a high potential for abuse. However, “psychedelics” is a term that encompasses a wide variety of substances. For example, while LSD, which was first derived from the Ergot fungus (a close relative of the Cordyceps fungus featured in the HBO series The Last of Us), remains a Schedule I drug along with fellow psychedelics; psilocybin, ibogaine and peyote (as well as cannabis), not all psychedelics are Schedule I drugs. Some psychedelics, such as ketamine, are listed in Schedule III, meaning that they have some currently accepted medical use and a lower potential for abuse.