Ayahuasca and tobacco smoking cessation: results from an online survey in Brazil

Tobacco smoking remains a leading global cause of death and disability, and conventional cessation interventions achieve sustained abstinence in only a minority of smokers. Recent clinical and survey evidence has suggested that serotonergic psychedelics can produce sustained reductions in tobacco use for some individuals, potentially via pharmacological effects on neuroplasticity and subjective mechanisms such as insight or mystical-type experiences. Ayahuasca, an Amazonian brew legally used in Brazil in religious and ritual settings, contains DMT plus monoamine oxidase inhibiting beta-carbolines and has been associated in observational work with reductions in substance use and withdrawal symptoms. Daldegan-Bueno and colleagues set out to identify factors associated with self-reported smoking cessation or reduction following ayahuasca consumption in a naturalistic sample. Using a retrospective, cross-sectional mixed-methods design, the study aimed to combine quantitative modelling (including scores on a mystical experience questionnaire) with inductive thematic analysis of free-text accounts to explore which demographic, smoking-related and ayahuasca-related variables predicted quitting versus reduction/relapse.

The study used an anonymous online survey conducted on the LimeSurvey platform between June and July 2018. Recruitment targeted social media and leaders of ayahuasca-using religious groups; the landing page invited people who had 'quit or reduced smoking after one or more ayahuasca experience' to participate. Inclusion required reporting quitting or reducing smoking after ayahuasca; exclusion criteria were age under 18, insufficient Portuguese literacy, prior participation, and history of psychiatric hospitalisation. Participants provided informed consent and the protocol received university ethics approval. Survey content combined closed and open questions on demographics, detailed smoking history (eg age of initiation, cigarettes per day, prior quit attempts, prior treatments), ayahuasca use (eg lifetime frequency, ritual context, intention to quit) and two open questions asking participants to describe the index ayahuasca experience and the cessation/reduction process. Standardised psychometric instruments were embedded: the Questionnaire on Smoking Urges — Brief (QSU-B), adapted to capture craving 6 months before the index experience and at survey completion; the Fagerström Test for Cigarette Dependence (FTCD), administered retrospectively for the 6 months before the index experience; and the 30-item Mystical Experience Questionnaire (MEQ30) with its four validated subscales (mystical, positive mood, transcendence of time/space and ineffability) in the Brazilian adaptation. Qualitative data from the two mandatory open questions (all n = 441 responses) were analysed using an exploratory, inductive semantic thematic analysis. One author coded responses and two co-authors reviewed the final themes; frequencies of respondents endorsing each theme were counted though themes were not mutually exclusive. Quantitative analysis grouped participants into 'cessation' (abstinent since index experience) and 'reduction/relapse' (reduced smoking, temporary cessation or later relapse). Group comparisons used Cramer's V and z-tests for categorical variables and generalised linear models (GZLM) for continuous variables; repeated-measure QSU-B scores were analysed with generalised estimating equations (GEE). A multivariate logistic regression examined predictors of smoking status across three nested models (sociodemographics; smoking and ayahuasca/MEQ30 variables; and a combined model). Bivariate odds ratios were also reported. Post hoc corrections and model-fit criteria (AIC, QIC) guided distributional choices; the cessation group served as reference in regressions.

Of 504 survey completers, 63 were excluded (54 ineligible; 9 inconsistent), leaving a final sample of 441 respondents. Most learned about the survey via social media (81.6%). By self-report, 305 participants (69.2%) reported quitting smoking since their index ayahuasca experience (cessation group) and 136 (30.8%) reported reduction or relapse. The sample had a mean age of 34.2 (± 10.9) years, comprised 52.8% women, and was highly educated (49.7% postgraduate); 71.6% were employed and 61.5% had no children. Participants began smoking on average at 16.29 (± 3.65) years; 59.9% smoked more than ten cigarettes per day and 40.6% had smoked for at least 10 years. Most (78.7%) had attempted quitting previously and 86.6% had not received prior treatment for smoking. Compared with the reduction/relapse group, the cessation group were older on average (p < 0.0001), more often in a relationship (p = 0.0014), more often parents (p < 0.0001), and had smoked for longer, consumed more cigarettes per day (p = 0.0002) and had higher FTCD scores six months prior to the index experience (GZLM group effect W(1) = 5.283, p = 0.0215). Regarding ayahuasca use, mean age at first use was 27.94 (± 9.24) years; 44.6% reported >50 lifetime uses and 39.2% drank ayahuasca fortnightly or more. Most (88.7%) had not attended their index ritual with the explicit intention of quitting smoking and 52.4% required more than one ayahuasca experience to change smoking. Ritual contexts included Santo Daime (44.4%), shamanic/neo‑shamanic (39.5%), União do Vegetal (16.8%) and indigenous (9.3%). The cessation group had a later first-use age (p = 0.0062), more lifetime ayahuasca experiences (p = 0.0044), longer time since the index experience (p = 0.0094), greater likelihood of having attended with an intention to quit (p = 0.0368) and required more experiences to stop (p = 0.0119). On craving (QSU-B), GEE analyses showed significant effects of group (W(1) = 24.605, p < 0.0001), time (W(1) = 1480.247, p < 0.0001) and their interaction (W(1) = 112.629, p < 0.0001); post hoc testing indicated higher pre-index craving in the cessation group and a marked reduction by survey completion (p < 0.0001). No between-group differences emerged on the four MEQ30 subscales in univariate tests. Multivariate logistic regression presented three models. In Model 1 (sociodemographics) older age (OR 1.03 per year, 95% CI 1.00–1.06, p = 0.0096) and being in a relationship (p = 0.0085) predicted cessation. Model 2 (smoking and ayahuasca variables) found longer prior smoking history (p = 0.0052), monthly ayahuasca frequency (OR 2.37, 95% CI 1.03–5.45, p = 0.0418), longer time since the index experience (OR 1.68, 95% CI 1.07–2.63, p = 0.0221) and higher total MEQ30 mystical experience score (OR 1.03, 95% CI 1.00–1.06, p = 0.0118) associated with cessation; by contrast the MEQ30 positive mood subscale was inversely associated (OR 0.91, 95% CI 0.85–0.97, p = 0.0070). In the combined Model 3 (best-fitting), being in a relationship (OR 1.81, 95% CI 1.15–2.85, p = 0.0095), frequent ayahuasca use (fortnightly, OR 2.16, 95% CI 1.00–4.70, p = 0.0513) and higher mystical experience scores (OR 1.03, 95% CI 1.00–1.05, p = 0.0240) predicted cessation, while the positive mood subscale again related to lower odds of cessation (OR 0.91, 95% CI 0.85–0.97, p = 0.0095). The frequency of ayahuasca intake emerged as one of the strongest protective factors. Qualitative analysis yielded eight themes from participants' accounts. Themes 1–5 described index-experience characteristics: acquired awareness (insight into smoking causes and self-care), sensorial experiences (aversive imagery, tastes or smells linked to tobacco), purging (physical excretions interpreted as cleansing), spiritual experiences (contact with spiritual entities or healing, awareness of smoking's spiritual impediment), and non‑specific/ineffable experiences. Themes 6–8 related to the cessation process: decreased desire/repulsion to cigarettes, immediate or gradual cessation (some reported effortless abstinence, others struggled), and increased motivation or determination to quit. Many respondents also reported wider positive changes after the index experience, including reduced alcohol (68.3%), reduced other drugs (44.2%) and reduced medication use (19.3%).

Daldegan-Bueno and colleagues interpret their findings as supporting a potential role for ayahuasca-related experiences in facilitating smoking cessation among a self-selected sample. The study team highlight that the cessation group began with a heavier smoking profile yet reported greater reductions in craving and a higher likelihood of sustained abstinence at survey completion. In multivariate models, higher scores on the MEQ30 mystical experience scale and greater frequency of ayahuasca intake predicted cessation even when controlling for sociodemographics and smoking history; unexpectedly, the MEQ30 positive mood subscale was associated with reduced odds of cessation. The authors situate their results alongside prior psilocybin and psychedelic survey literature that links mystical- or insight-type experiences with enduring behavioural change. They propose mechanisms that include both neurobiological effects and subjective processes such as insights, shifts in values and reductions in anxiety or depression. Qualitative themes were consistent with these mechanisms, emphasising increased self-awareness, sensorial aversion to tobacco, purgative experiences and heightened motivation. The paper also notes cultural factors specific to Brazilian ayahuasca use, including the 'peia' concept (a challenging cleansing experience) and ritual settings that may augment expectations and social pressures for behaviour change. Several limitations are acknowledged. The convenience, self-selected sample prevents estimating prevalence and limits generalisability; group assignment relied on self-reported abstinence without biochemical verification; recall bias and the retrospective anchoring to a single 'index' experience may have influenced responses; ritual contexts and membership in organised ayahuasca groups could confound effects through social mechanisms; the study did not assess other forms of tobacco use such as rapé; and multiple comparisons were largely uncorrected, so some reported associations might lose statistical significance after stringent correction. The authors therefore refrain from causal claims and emphasise the need for controlled prospective studies. In terms of implications, the investigators suggest that the observed associations motivate further rigorous research — including randomised or open‑label prospective trials — to evaluate ayahuasca or psychedelic-assisted approaches for tobacco cessation, and to clarify the roles of mystical-type experiences, the positive mood component, and the optimal intensity/frequency of psychedelic exposure.

In this convenience sample of people who attributed smoking reduction or cessation to ayahuasca use, higher mystical-experience scores and more frequent ayahuasca intake were associated with greater odds of quitting, while the positive mood component of the MEQ30 was unexpectedly linked to lower odds. Participants also described broader health-related improvements such as reduced alcohol or drug use and healthier lifestyles. The authors conclude that these findings add to evidence suggesting psychedelics, and ayahuasca in particular, warrant further investigation as potential tools for smoking cessation, and they call for rigorous, controlled studies to test efficacy, evaluate mechanisms and examine dose‑frequency effects, especially given Brazil's unique cultural context and the global burden of tobacco-related disease.