A recent study in the Journal of Substance Use and Misuse reported on ‘near death experiences’ by users of the anaesthetic drug ketamine which is also widely used illicitly for its hallucinogenic effects.
‘Near death experiences’ are most commonly associated with being seriously ill or injured, although one of my favourite studies found that about half of people who reported the events were never actually in danger of dying.
NDEs typically involve a ‘light at the end of the tunnel’ experience, having life flash before your eyes, feeling detached from the body, the experience of making a decision to ‘return to life’, a sense of profound peace and a feeling of communicating with non-physical beings.
There were anecdotal reports that ketamine can produce similar effects with ‘out of body experiences’ being common at high doses. Additionally, the drug targets the glutamate system in the brain which has also been implicated in NDEs that don’t involved the drug.
To understand how closely the drug produces the classic NDE experiences, researchers Ornella Corazza‚Äå and Fabrizio Schifano‚Äå asked ketamine users to anonymously complete a questionnaire on the internet and then invited those who reported an NDE on a validated assessment for an interview.
The results are fascinating:
Interestingly, in 45 (90%) cases, the NDE state occurred either during the first five occasions of intake or during the first few experiences after long spells of ketamine-free periods. On further occasions of intake, ketamine was typically perceived as a stimulant. In terms of the Greyson NDE Scale (see Table 2), the subjects‚Äô perception of time seemed to be altered as typically described during an NDE: 45 (90%) participants reported that everything seemed to be happening at once, or that time lost all its meaning, while 5 (10%) perceived a complete ‚Äúabsence of time‚Äù during the experience.
The sense of dissociation from the physical body was experienced by 44 subjects (88%), who claimed that they left their bodies and existed outside it or that they lost awareness of their bodies. Thirteen subjects (26%) clearly described a travel along a tunnel, or through a spiral, with a brilliant light at the end or experienced a more general sense of light, or of flashing lights. Fifteen (30%) participants somewhat met with a ‚Äúbeing,‚Äù or heard a definite voice of mystical or unearthly nature. An infrequently described feature was the so-called ‚Äúlife review.‚Äù Twelve (24%) subjects reported that they were able to either vividly ‚Äúreview‚Äù past events, or felt that their past ‚Äúflashed before them, out of control.‚Äù
Furthermore, 10 (20%) subjects reported that during their experience they were ‚Äúaware of things going on elsewhere,‚Äù as if by extrasensory perceptions. At the question ‚ÄúDid you suddenly seem to understand everything?‚Äù most interviewees (26, 52%), answered that they achieved ‚Äúa total understanding of the universe.‚Äù Only 4 (8%) participants approached a sort of ‚Äúbarrier‚Äù or ‚Äúa point of no return,‚Äù which was described as ‚Äúthe limit between earthly life and the next life.‚Äù This could have been an edge, a wall, or a river, among other patterns. Thirty-six (72%) respondents experienced an ineffable sense of peace and pleasantness, and 38 (76%) subjects described an ‚Äúincredible joy.‚Äù
Link to PubMed entry for study.