Assessment of Alcohol and Tobacco Use Disorders Among Religious Users of Ayahuasca

Alcohol and tobacco use disorders remain major global public health problems, causing substantial morbidity and mortality despite a wide array of current treatments. Earlier research has suggested that ritual use of ayahuasca, a brew containing N,N-dimethyltryptamine (DMT) and β-carbolines, may be associated with reduced substance-use problems. Small case-control and cross-sectional studies, plus some prospective and programmatic reports, have reported lower recent alcohol and other drug use among members of religious ayahuasca groups such as União do Vegetal (UDV), Santo Daime and Barquinha, although findings have been mixed and many studies were limited by small samples, heterogeneous settings and non-rigorous designs. Ramchandani and colleagues set out to extend this evidence by analysing patterns of alcohol and tobacco use and disorder in a much larger sample of UDV members drawn from 10 Brazilian states. The study compared prevalence of lifetime and current alcohol and tobacco use and substance-use disorder in the UDV sample with a national Brazilian normative survey, and examined whether recent ceremonial attendance and years of UDV membership were associated with lower likelihood of alcohol and tobacco use and disorder.

This was a cross-sectional survey of 1,947 UDV volunteers conducted between March 2009 and August 2011. Participants were recruited from 35 UDV temples across 10 Brazilian states representing the country's five major regions. Efforts were made to exhaustively sample members attending each temple on a single day; volunteers completed either paper or online questionnaires after giving written consent. The study received institutional ethics approval. Sociodemographic data collected included age, sex, years of education, marital and employment status. Measures of religious involvement captured years of UDV membership and frequency of ritual (ayahuasca) attendance during the previous 12 months, including number of ceremonies attended. Substance use and disorder were assessed using instruments adapted for Brazil: the Substance Abuse and Mental Health Services Administration (SAMHSA) questionnaire (from a national household survey, used here as the normative comparator) and alcohol/tobacco sections of a WHO-based questionnaire. The SAMHSA-based instrument flags a substance-use disorder when respondents endorse two or more of six problem-related items (time spent obtaining/recovering from the drug, use in larger quantities or more often than intended, tolerance, physical risks, interpersonal problems, and desire to cut down). Statistical analyses were performed in SPSS 20.0. Binomial tests for proportions compared lifetime use and SAMHSA-defined substance-use disorder prevalence between the UDV sample (and a UDV subsample with >3 years membership) and the Brazilian normative sample (n = 7,939) stratified by age ranges. Hierarchical logistic regression models tested whether ceremonial attendance in the previous 12 months and a binary indicator of UDV membership (>3 years versus ≤3 years) predicted dichotomous outcomes for substance use (past 12 months, past 30 days) and meeting SAMHSA criteria for substance-use disorder. The first regression block included age, sex and education; the second block added the ayahuasca attendance variables. Multicollinearity was assessed using Pearson and Spearman correlations and Variance Inflation Factor (VIF) with pre-specified thresholds. Statistical significance was set at p < 0.05.

The surveyed UDV sample (n = 1,947) had a mean age of 39.85 years (range 18–81), with a roughly equal gender distribution (50.8% male, 49.2% female). Most respondents (68.4%) were married or in a stable relationship. Mean years of UDV membership were 9.44 and mean number of ceremonies attended in the last year was 34.99. The majority (68.7%) were from the central, south and southeast regions of Brazil. Comparisons with the national survey data showed that lifetime use of alcohol and tobacco was higher in the UDV sample than in Brazilian norms for the 25–34 and >34 age groups, but not for the 18–24 group; nearly all these differences were statistically significant (p < 0.001) except lifetime tobacco use in the 18–24 band. In contrast, current prevalence of alcohol and tobacco use disorder (SAMHSA criteria) was significantly lower in the UDV sample than in the national norms across all age ranges. When the national norms were compared specifically with the UDV subsample of members with more than 3 years' membership, the differences in lower current disorder prevalence were of larger magnitude. Hierarchical logistic regression results for alcohol outcomes indicated that adding ayahuasca attendance variables substantially increased explained variance for alcohol use in the previous 12 months (Nagelkerke R² reported increases; exact baseline and delta values appear in the extracted text but are partially fragmented). Greater frequency of UDV session attendance during the previous 12 months was associated with lower odds of alcohol use in the previous 12 months (OR 0.936, 95% CI 0.917–0.954; p < 0.001), lower odds of alcohol use in the previous 30 days (OR 0.907, 95% CI 0.880–0.936; p < 0.001), and lower odds of meeting criteria for alcohol use disorder (OR 0.946, 95% CI 0.904–0.991; p = 0.018). Having more than 3 years of UDV membership was also associated with markedly lower odds of alcohol use in the previous 12 months (OR 0.226, 95% CI 0.154–0.332; p < 0.001), in the previous 30 days (OR 0.401, 95% CI 0.221–0.727; p = 0.003), and of alcohol use disorder (OR 0.169, 95% CI 0.062–0.464; p = 0.001). In the full models a Bachelor's degree was associated with increased likelihood of alcohol use in the previous 12 months (OR 1.760, 95% CI 1.202–2.578; p = 0.003) and in the previous 30 days (OR 2.819, 95% CI 1.479–5.374; p = 0.002). Age was inversely associated with meeting criteria for alcohol use disorder (OR 0.946 per year, 95% CI 0.900–0.993; p = 0.026). The extracted text begins reporting tobacco regression results with a sentence fragment indicating that age, sex and education explained about 1% (p = 0.292) of tobacco use in the previous 12 months, but the remainder of the tobacco regression results are not present in the extraction. The abstract and discussion assert that attendance and years of membership significantly predicted reductions in tobacco use and tobacco use disorder, but detailed tobacco-specific regression coefficients and related statistics are not fully available in the provided text.

Ramchandani and colleagues interpret their findings as showing substantially lower current rates of alcohol and tobacco use disorder among UDV members compared with Brazilian norms, despite higher lifetime exposure to these substances in older UDV members. They note that ceremonial attendance during the previous 12 months and length of UDV membership were stronger predictors of reduced alcohol and tobacco use and disorder than the sociodemographic variables (age, sex, education). The authors argue that these patterns are consistent with earlier studies reporting reduced recent substance problems among religious ayahuasca users, while acknowledging an exception in Lawn et al.'s survey that found more problematic drinking among ayahuasca users compared with non-psychedelic users; Ramchandani and colleagues suggest that regular, structured religious contexts and institutional restrictions on alcohol and tobacco use in UDV may underlie more favourable outcomes compared with occasional, unstructured ayahuasca use. The discussion outlines several possible mechanisms for the observed associations. Pharmacological explanations focus on the combined actions of DMT and β-carbolines on monoaminergic systems, including modulation of serotonergic receptors (5-HT2A/2C), effects on mesolimbic dopamine pathways, sigma-1 receptor interactions, and influences on neuroplasticity that could disrupt maladaptive addiction-related learning. The authors also emphasise contextual and psychosocial factors: the ritual ‘‘set and setting,’’ visionary experiences that may promote insight into personal history, the social support and normative pressures of the religious community, and therapeutic elements of ritual processing. These mechanisms are presented as complementary rather than mutually exclusive. Key limitations acknowledged by the authors include the cross-sectional design, which precludes firm causal inference, and susceptibility to self-selection and recall biases. The design does not allow separation of pharmacological effects of ayahuasca from the social and religious dimensions of UDV attendance. The authors highlight the study's major strength as its sample size and the focus on regular, institutionalised ayahuasca users, and they recommend further research to clarify physiological mechanisms and to test isolated constituents (for example DMT and harmaline) in controlled double-blind designs.

The authors conclude that this large cross-sectional survey adds evidence that regular, ritualised ayahuasca use within the UDV is associated with lower current levels of alcohol and tobacco dependence compared with the general population, even though members report higher historical use prior to joining the church. They argue that frequency of ceremonial ingestion and longer membership show substantial negative associations with substance use and disorder, but they caution that the study's cross-sectional nature limits causal claims and that self-selection and recall bias may influence results. Ramchandani and colleagues recommend future research, including double-blind studies that isolate ayahuasca constituents, to better establish physiological mechanisms underlying potential anti-addictive effects.