PLoS ONE
April 23, 2019
Roland R. Griffiths, Ethan Hurwitz, Alan K. Davis et al.
249 citations
Experiences interpreted as personal encounters with God, whether occurring naturally or after taking psychedelic drugs, share striking similarities. In an online survey of over 4,200 people, those who had a nondrug encounter most often called it God, whereas those who had a psychedelic encounter most often called it Ultimate Reality. Regardless of origin, most participants vividly remembered the encounter as involving a conscious, benevolent, intelligent, sacred, eternal, and all-knowing presence. About half of all encounters met criteria for a complete mystical experience. More than two-thirds of self-identified atheists no longer identified as atheist afterward.
Psychopharmacology
February 1, 2018
Theresa M Carbonaro, Matthew W Johnson, Ethan Hurwitz et al.
139 citations
Psilocybin and dextromethorphan (DXM) both produce powerful subjective effects, but their experiences differ profoundly. In a double-blind comparison with 20 participants, high doses of both drugs caused similar overall drug effect strength and time-course. Psilocybin uniquely fostered richer, more complex visual experiences—including more movement, brightness, and kaleidoscopic imagery—along with greater mystical-type and psychologically insightful experiences and deeper music absorption. DXM, by contrast, produced stronger feelings of disembodiment, nausea, and light-headedness. Both drugs increased blood pressure, heart rate, and pupil dilation while impairing motor performance and balance.
Psychopharmacology
October 1, 2018
Frederick S Barrett, Theresa M Carbonaro, Ethan Hurwitz et al.
109 citations
Classic psychedelics and dissociative hallucinogens may share some neuropsychological effects despite different pharmacology. In a double-blind, placebo-controlled study, 20 hallucinogen users received 10, 20, and 30 mg/70 kg psilocybin, 400 mg/70 kg dextromethorphan (DXM), and placebo across five sessions. Neither drug caused global cognitive impairment. Psilocybin produced dose-dependent effects on psychomotor performance, working memory, episodic memory, associative learning, and visual perception. DXM affected psychomotor performance, visual perception, and associative learning similarly to moderate-to-high psilocybin doses. Psilocybin affected working memory more than DXM, while DXM had greater effects on balance, episodic memory, response inhibition, and executive control.
PLoS ONE
August 24, 2022
Mary M. Sweeney, Sandeep M. Nayak, Ethan Hurwitz et al.
60 citations
Psychedelic drug experiences and near-death or other non-ordinary experiences both change people's beliefs about death, but direct comparisons are rare. In a survey of 3,192 individuals who reported such experiences, those from non-drug causes (e.g., near-death) were more likely to involve unconsciousness, clinical death, or imminent danger. Both groups reported similar reductions in fear of death, high personal meaning, spiritual significance, and psychological insight. However, psychedelic participants scored higher on standardized measures of mystical and near-death features, while non-drug participants more often rated their experience as the single most meaningful of their lives. Among psychedelics, ayahuasca and DMT produced stronger positive enduring effects than psilocybin and LSD.