Recent research offers good reason to think that various psychedelic drugs—including psilocybin, ayahuasca, ketamine, MDMA, and LSD—may have significant therapeutic potential in the treatment of various mental health conditions, including post-traumatic stress disorder, depression, existential distress, and addiction. Although the use of psychoactive drugs, such as Diazepam or Ritalin, is well established, psychedelics arguably represent a therapeutic step change. As experiential therapies, their value would seem to lie in the subjective experiences they induce.