Psychedelic

After assessing the semantic similarity between 15,000 reports linked to the use of 165 psychoactive substances and 625 NDE narratives, we determined that the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine consistently resulted in reports most similar to those associated with NDEs. Ketamine was followed by Salvia divinorum (a plant containing a potent and selective receptor agonist) and a series of serotonergic psychedelics, including the endogenous serotonin 2A receptor agonist N,N-Dimethyltryptamine (DMT). This similarity was driven by semantic concepts related to consciousness of the self and the environment, but also by those associated with the therapeutic, ceremonial and religious aspects of drug use. Our analysis sheds light on the long-standing link between certain drugs and the experience of “dying“, suggests that ketamine could be used as a safe and reversible experimental model for NDE phenomenology, and supports the speculation that endogenous NMDA antagonists with neuroprotective properties may be released in the proximity of death.

•Study on the prevalence and associations of challenging, difficult, or distressing classic psychedelic experiences.
•Self-reported co-use of certain medications (e.g., lithium) was associated with degree of difficulty and risk of harm.
•Various set and setting variables (e.g., no psychological support) were associated with degree of difficulty and risk of harm.

Ketamine’s remarkable effect bolsters a new theory of mental illness.