“Bad trips” are very real and can be one of “the most challenging experiences of [a] lifetime,” according to a large survey of psychedelic users asked about their experiences.* But it’s important to distinguish what can happen when these drugs are used in uncontrolled situations, without attention to set and setting, from what happens under clinical conditions, after careful screening and under supervision. Since the revival of sanctioned psychedelic research beginning in the 1990s, nearly a thousand volunteers have been dosed, and not a single serious adverse event has been reported.
