Comparison of psychedelic and near-death or other non-ordinary experiences in changing attitudes about death and dying

Classic psychedelics such as psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) can occasion a wide range of acute subjective effects, including mystical-type experiences characterised by unity, sacredness, ineffability, and transcendence of time and space. Prior controlled research has linked drug‑occasioned mystical experiences to persistent positive changes in attitudes, mood and behaviour, and clinical trials with psilocybin have shown reductions in death anxiety among patients with life‑threatening illness. Separately, spontaneous non‑drug phenomena such as near‑death experiences (NDEs) and out‑of‑body experiences can produce similar enduring changes in attitudes about death; the Greyson Near‑Death Experience Scale was developed to quantify common phenomenological features of such events. Despite overlapping phenomenology and therapeutic interest, few studies have directly compared psychedelic‑occasioned experiences with non‑drug near‑death or other non‑ordinary experiences on common quantitative metrics. Sweeney and colleagues designed the present study to fill that gap by directly comparing people who reported a single experience that fundamentally changed their beliefs about death and dying, where the experience was either occasioned by a classic psychedelic (psilocybin, LSD, ayahuasca, or non‑ayahuasca DMT) or was a near‑death or other non‑ordinary experience occurring without psychedelic drugs. The investigation aimed to characterise contextual features of the experiences, acute phenomenology using standard instruments (for example the Mystical Experience Questionnaire and the Greyson NDE Scale), changes in death attitudes (using the Revised Death Attitude Profile, DAP‑R), and persisting personal and spiritual consequences attributed to the experience.

The study used two parallel online surveys (one targeted to near‑death/other non‑ordinary experiences and one to psychedelic experiences) administered via Qualtrics between 4 December 2015 and 5 April 2018. Recruitment relied on internet advertisements, email invitations, organisational newsletters and online forums relevant to near‑death experiences and psychedelics. Written informed consent was obtained on the survey landing page, participation was anonymous and uncompensated, and the Johns Hopkins University School of Medicine Institutional Review Board approved procedures. Eligibility required participants to be ≥18 years old, fluent in English, not previously having taken the survey and to report a single experience that fundamentally altered their beliefs about death and dying. Psychedelic survey respondents additionally indicated the experience followed use of a specified classic psychedelic (psilocybin, LSD, ayahuasca, or inhaled/smoked DMT, excluding 5‑MeO‑DMT). Exclusion criteria included endorsement of concurrent non‑medical use of other psychoactive drugs (except caffeine or nicotine), reporting multiple experiences rather than a single memorable event, or asking that their response not be used. Participants provided demographic information and described the circumstance of the experience. Standardised psychometric instruments assessed acute phenomenology and enduring effects: the 30‑item Mystical Experience Questionnaire (MEQ‑30), the 16‑item Greyson Near‑Death Experience (NDE) Scale, selected items from the Hallucinogen Rating Scale and States of Consciousness Questionnaire, the Persisting Effects Questionnaire, and the DAP‑R to rate death attitudes before and after the experience (items scored on 7‑point Likert scales). A single yes/no item asked whether respondents encountered something someone might call "God." A priori, a "complete" mystical experience on the MEQ‑30 was defined as ≥60% on each of the four MEQ subscales. Statistical analyses compared the Non‑Drug Group and the Psychedelic Group and also compared across the four psychedelic drug groups. Linear regressions were used for continuous outcomes and logistic regressions for binary outcomes, each model including covariates for age at survey, sex, race/ethnicity (White non‑Hispanic vs other), US residence, marital status, annual income (≥50K USD vs <50K USD), and education (undergraduate degree or higher vs not). Pairwise comparisons among drug groups used generalised linear models with Type III sums of squares and Bonferroni adjustment. Results were considered statistically significant at p ≤ 0.001; the authors emphasised differences that were both statistically significant and exceeded 10% in magnitude to focus on robust effects. Recruitment flow yielded 15,956 survey starts, with exclusions for ineligibility, non‑completion, concurrent disallowed drug use, multiple experiences, and other reasons. The final analysed sample comprised 3,192 respondents: 2,259 in the Psychedelic Group (LSD n = 904, psilocybin n = 766, ayahuasca n = 282, inhaled/smoked DMT n = 307) and 933 in the Non‑Drug Group. Median survey completion time was 45 minutes. The extraction does not report whether baseline religious or afterlife beliefs were measured prior to the indexed experience; the authors note those variables were described but not adjudicated as pre‑existing versus changed by the experience.

Sample demographics differed between groups. Respondents who reported non‑drug experiences were older at the time of the experience (mean 32.0 vs 25.0 years) and at time of survey participation (mean 55.2 vs 31.7 years) and included a higher proportion of females (68% vs 22% in the Psychedelic Group). The sample was predominantly White and non‑Hispanic; the Psychedelic Group had lower rates of college degrees and lower income overall relative to the Non‑Drug Group. The Ayahuasca subgroup was older and more often female, college educated and married than other psychedelic subgroups. Circumstances of the indexed event diverged by group. Psychedelic experiences more commonly lasted an hour or more (66% vs 31% in the Non‑Drug Group), whereas 40% of non‑drug respondents reported very brief experiences (≤5 minutes) compared with 7% of the Psychedelic Group. Non‑drug respondents were substantially more likely to report being medically unconscious (36% vs 10%) or clinically dead (21% reported self‑perception of clinical death, 11% had medical confirmation) and to report their life was in imminent danger (47% vs 3%). Among psychedelics, the DMT subgroup reported the shortest durations and a higher prevalence of complete unresponsiveness relative to other drug subgroups, although clinical death remained rare in all drug groups. On standardised measures of mystical and near‑death phenomenology both groups scored highly, but psychedelic‑occasioned experiences tended to produce larger scores. MEQ‑30 total and subscale scores exceeded 50% of maximum in both groups; 55% of the Psychedelic Group met a priori criteria for a "complete" mystical experience versus 47% in the Non‑Drug Group. By drug, MEQ complete mystical experience rates were 73% for DMT, 68% for ayahuasca, 51% for psilocybin, and 48% for LSD. Greyson NDE Scale total and subscale scores were also higher in the Psychedelic Group than the Non‑Drug Group, with the largest relative difference seen on the cognitive subscale (items such as speeded time, scenes from the past, sudden understanding). The MEQ and NDE Scale were strongly positively correlated (Pearson r = 0.77 overall, r = 0.82 in the Non‑Drug Group, r = 0.72 in the Psychedelic Group). Specific phenomenological contrasts included higher ratings in the Psychedelic Group for "feeling of being reborn" and greater endorsement overall of encountering "something someone might call 'God'" (56% psychedelic vs 48% non‑drug). Encountering something characterised as "God" was most frequently reported in the ayahuasca (71%) and DMT (68%) subgroups, versus 54% for psilocybin and 49% for LSD. Conversely, the Non‑Drug Group reported stronger convincing feelings of contact with deceased people and of obtaining information extrasensorily; ayahuasca respondents reported relatively high ratings on extrasensory information and reliving childhood situations, whereas DMT respondents had lower ratings on reliving childhood events. Changes in death attitudes were broadly similar and largely positive across groups. A large majority in both groups reported a decrease in fear of death (89% Psychedelic, 88% Non‑Drug). On the DAP‑R change scores expressed as percentage of maximum possible change, both groups showed comparable decreases in fear of death (approximately 36–39%). The Non‑Drug Group showed a larger decrease in death avoidance (34% decrease) than the psychedelic subgroups (22–24% decrease) and a larger increase in approach acceptance (19% vs 7–15%). Neutral acceptance and escape acceptance subscales showed small or inconsistent changes across groups. Participants attributed substantial persisting positive effects to their experiences: moderate improvements in personal wellbeing, life satisfaction, sense of purpose and meaning, social relationships, mood and spirituality were reported across both groups. When asked to rate the experience relative to other lifetime events, both groups gave high ratings for personal meaning, spiritual significance and psychological insight, but Non‑Drug respondents were more likely to rate their experience as the single most meaningful, spiritually significant, insightful and challenging event of their life. Comparing psychedelics, psilocybin and LSD were largely indistinguishable across outcome measures, while ayahuasca and DMT tended to show stronger mystical/NDE scores and more positive enduring consequences.

Sweeney and colleagues interpret the findings as demonstrating considerable overlap between psychedelic‑occasioned and non‑drug near‑death or other non‑ordinary experiences in terms of phenomenology and enduring positive changes in attitudes about death and personal wellbeing. Both types of experiences produced large and similar reductions in self‑reported fear of death and high ratings of personal meaning, spiritual significance and psychological insight. At the same time, the psychedelic‑occasioned experiences—particularly those attributed to ayahuasca and inhaled/smoked DMT—tended to score higher on standardised measures of mystical experience (MEQ‑30) and near‑death phenomenology (Greyson NDE Scale), whereas non‑drug respondents more often reported convincing contact with deceased individuals and were more likely to rate the event as the single most meaningful experience of their life. The authors situate these results alongside prior clinical and survey work showing psychedelics can reduce death anxiety and produce enduring changes; they note concordance with experimental DMT studies that increased NDE‑scale ratings and with prior survey findings of high meaning and spiritual significance after "God encounter" and DMT entity encounters. Sweeney and colleagues propose that the phenomenology associated with near‑death experiences can occur outside contexts of actual life threat, since psychedelic respondents reported high NDE‑scale scores despite rarely reporting imminent danger. The investigators acknowledge several important limitations that constrain interpretation. Data were retrospective and self‑reported, respondents were self‑selected and thus not necessarily representative, and the sample was demographically skewed (predominantly White, male in the psychedelic sample, and concentrated in certain countries). Low survey completion rate further limits generalisability. Cross‑sectional design prevents causal inference and some group differences may have pre‑dated the indexed experience. Relevant contextual factors such as ceremonial versus recreational setting were not comprehensively measured, and only a subset of classic psychedelics was included. The authors also note that a substantial fraction of non‑drug respondents described events that were not clearly near‑death as conventionally defined, highlighting heterogeneity within the Non‑Drug Group and the need for finer contextual measurement in future work. On the basis of these findings, the authors recommend further prospective experimental and clinical observational research to clarify mechanisms by which both psychedelic and non‑drug experiences alter death attitudes and to evaluate potential clinical utility for alleviating suffering related to fear of death in end‑of‑life care and other settings.

The authors conclude that both psychedelic‑occasioned and non‑drug near‑death/other non‑ordinary experiences can produce strikingly similar phenomenological effects and enduring positive changes in attitudes about death, reductions in fear of death, and improvements in personal wellbeing and life meaning. Psychedelic experiences tended to yield higher scores on standardised mystical and near‑death measures, while non‑drug experiences were more often rated as the single most meaningful or spiritually significant life event. Among psychedelics, ayahuasca and DMT were associated with stronger and more positive enduring consequences than psilocybin and LSD. Sweeney and colleagues suggest these results support further prospective and clinical research to elucidate mechanisms and potential therapeutic applications for fear of death and related distress.