Impact of a Naturalistic Psychedelic Experience on Smoking: A Retrospective Survey

Data were collected via an online survey posted on the French Psychedelic Society website and social media from November 2021 to April 2022. Eligible respondents were at least 18 years old, fluent in French, and had experienced at least one psychedelic episode more than six months earlier while they were smokers. The protocol received institutional ethical approval and all participants provided informed consent. From 189 respondents who supplied smoking information for the three timepoints of interest, exclusions for use of non‑classic hallucinogens (n = 4), failure to name the psychedelic (n = 1), and not smoking at the time of the experience (n = 11) yielded a final sample of 173 participants. Participants were instructed to recall the single most significant psychedelic experience they had while smoking and to report demographics, the time since that experience, their main intention for the experience (recreational, curiosity, self‑exploration/improvement, healing/therapeutic, spiritual/religious, other), and which psychedelic was used. Three validated questionnaires were administered retrospectively for three periods (the six months before the experience, the month after the experience, and the most recent six months): the revised Mystical Experience Questionnaire (MEQ‑30) as a behavioural marker of acute mystical‑type experiences, the Fagerström Test for Cigarette Dependence (FTCD) to categorise tobacco dependence severity, and the Acceptance and Action Questionnaire (AAQ‑II) to assess psychological flexibility. A ‘‘full’’ mystical experience was operationalised per MEQ‑30 convention (mean score ≥ 60% on each subscale). Missing demographic items were present for small numbers of respondents and were handled with pairwise deletion; no imputation was performed. The primary analytic strategy categorised participants into those who reduced or quit smoking versus those who did not, based on change in cigarettes per day from baseline (six months prior) to the last six months; the 25 participants who reported complete abstinence were combined with 68 participants who reported a reduction, because quitters alone were few. Statistical tests included within‑subjects ANOVA for repeated measures (AAQ‑II scores and cigarettes per day), McNemar tests for changes in FTCD categories, two‑sample t‑tests and Fisher exact tests for group comparisons, correlation analyses between MEQ‑30, AAQ‑II change and smoking change, and a logistic regression predicting smoking reduction/cessation with motive, MEQ‑30 total, baseline FTCD, and AAQ‑II change as independent variables. For the motive predictor, small or ambiguous categories were excluded from the regression. Analyses were performed in R 4.0.3.

Sample characteristics: The final sample (N = 173) had mean age 29.9 years (SD = 9.21), 29.5% women, 50.3% men, and 20.2% non‑reported gender. Mean cigarettes per day at baseline were 9.83 (SD = 6.88) and mean smoking duration was 13.6 years (SD = 8.55). According to the FTCD at baseline, 53.8% were categorised as very low dependence, 23.1% low, 5.2% moderate, 12.7% high and 5.2% very high. The mean MEQ‑30 score for the reference experience was 2.92 (SD = 0.99) and 25% met criteria for a full mystical experience. Substances reported for the reference experience were predominantly LSD (61.3%) and psilocybin (30.1%). The mean baseline AAQ‑II score was 43.06 (SD = 11.12); AAQ‑II increased by mean 4.14 (SD = 8.99) at one month and by 5.72 (SD = 8.76) at the last six months. Effect on smoking and dependence: A within‑subjects ANOVA indicated a significant main effect of the psychedelic experience on cigarettes per day, F(2, 171) = 35.57, p < .001. Pairwise comparisons showed a significant decrease from baseline (M = 9.83) to the month following the experience (M = 8.42), and further decrease to the last six months (M = 7.36); all pairwise contrasts reported adjusted p < .001. FTCD category analyses found an increased proportion with very low dependence at the last six months (65.3%) compared to the six months prior (53.8%), p (adjusted) = .002, and a decreased proportion with high dependence in the month after (5.8%) and at the last six months (5.2%) compared to baseline (12.7%), p (adjusted) = .01 and .006 respectively. Correlational findings: Greater reductions in cigarettes per day (baseline to last six months) were negatively associated with the change in AAQ‑II score (r = -.281, p < .01), MEQ‑30 total score (r = -.163, p = .03) and the MEQ‑30 mystical subscore (r = -.169, p = .03). Change in AAQ‑II between baseline and one month post was positively correlated with MEQ‑30 total (r = .18, p = .039). Group comparisons: Ninety‑three participants reduced or quit smoking (25 quit completely) and 80 did not change. No group differences were observed for age, gender, age of first cigarette, baseline cigarettes per day, age at the psychedelic experience, intention to quit, substance type, or estimated dose. Participants who reduced or quit were more likely to have graduate education (75.5% vs 48.7%), had shorter smoking duration (11.8 vs 15.5 years, t(167) = -2.84, p < .01), higher mean MEQ‑30 scores (3.11 vs 2.71, t(171) = 2.7, p < .01), a higher rate of full mystical experience (33% vs 16%, p = .01), and lower baseline AAQ‑II (41.1 vs 45.3, t(153) = -2.4, p = .018). The motive for the psychedelic experience differed between groups, with fewer recreational motives (34.4% vs 56.3%) and more self‑exploration motives (34.4% vs 17.5%) among those who reduced or quit. Prediction of reduction/cessation: In the logistic regression, MEQ‑30 total (Exp(B) = 1.33, p = .21) and baseline Fagerström score (Exp(B) = 0.87, p = .14) did not significantly predict group membership. However, the change in AAQ‑II between baseline and the last six months was a significant predictor (Exp(B) = 1.12, p = .002), and the motive for the experience also reached significance (p = .04).

Romeo and colleagues interpret their findings as suggesting that a past naturalistic psychedelic experience can be associated with subsequent reductions in cigarette consumption and tobacco dependence severity. Respondents who reduced or quit smoking were more likely to have experienced a more intense mystical episode, to have undertaken the psychedelic experience for self‑exploration rather than purely recreational reasons, and to show larger increases in psychological flexibility. The investigators highlight the association between increases in psychological flexibility (AAQ‑II change) and smoking reduction as the principal predictive result, consistent with theories that psychological flexibility may mediate psychedelic therapeutic effects. The authors situate their results alongside prior work, including a small controlled psilocybin‑assisted therapy trial reporting high short‑term abstinence rates, and other studies linking mystical intensity to improved outcomes in alcohol and tobacco samples. Mechanistic explanations discussed include biological pathways (5‑HT2A agonism leading to glutamate release and downstream cortical effects) and psychological processes (relaxed beliefs, increased self‑determination and psychological flexibility). The observed correlations between MEQ‑30 and AAQ‑II change, and the lower baseline psychological flexibility among those who later reduced or quit, are offered as evidence consistent with the idea that individuals with greater scope for psychological change may derive larger benefits. The authors acknowledge several limitations that constrain inference: the retrospective design and reliance on recall of a single ‘‘most significant’’ psychedelic experience may introduce retrieval and selection biases and precludes causal claims; the sample size is modest and the analyses combined reducers and quitters due to small numbers of abstainers; important contextual information about the setting of psychedelic use was not collected; and some motive categories were too small to include in regression models. Romeo and colleagues therefore conclude that, while the naturalistic data are consistent with potential therapeutic effects of psychedelics on tobacco use, these associations require confirmation in larger, controlled prospective studies.