" Completed studies suggest that psilocybin—or rather the mystical state of consciousness that psilocybin occasions—may be useful in treating both addiction (a pilot study in smoking cessation achieved an 80 percent success rate, which is unprecedented) and the existential distress that often debilitates people facing a terminal diagnosis. When we last met, Griffiths was about to submit an article reporting striking results in the lab’s trial using psilocybin to treat the anxiety and depression of cancer patients; the study found one of the largest treatment effects ever demonstrated for a psychiatric intervention. The majority of volunteers who had a mystical experience reported that their fear of death had either greatly diminished or completely disappeared. "

― Michael Pollan , How to Change Your Mind: What the New Science of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression, and Transcendence