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

This survey study (n=1947) indicates an association between reduced current tobacco and alcohol use and attendance of religious ayahuasca ceremonies. Lifetime use of these substances, however, was higher in the ceremony-attending group in most age groups.


“The aims of this study were to assess the impact of ceremonial use of ayahuasca—a psychedelic brew containing N,N-dimethyltryptamine (DMT) and β-carboline —and attendance at União do Vegetal (UDV) meetings on substance abuse; here we report the findings related to alcohol and tobacco use disorder. A total of 1,947 members of UDV 18+ years old were evaluated in terms of years of membership and ceremonial attendance during the previous 12 months. Participants were recruited from 10 states from all major regions of Brazil. Alcohol and tobacco use was evaluated through questionnaires first developed by the World Health Organization and the Substance Abuse and Mental Health Services Administration. Analyses compared levels of alcohol and tobacco use disorder between the UDV and a national normative sample (n = 7,939). Binomial tests for proportions indicated that lifetime use of alcohol and tobacco was higher in UDV sample compared to the Brazilian norms for age ranges of 25–34 and over 34 years old, but not for the age range of 18–24 years old. However, current use disorders for alcohol and tobacco were significantly lower in the UDV sample than the Brazilian norms. Regression analyses revealed a significant impact of attendance at ayahuasca ceremonies during the previous 12 months and years of UDV membership on the reduction of alcohol and tobacco use disorder.”

Authors: Paulo Cesar Ribeiro Barbosa, Luís F. Tófoli, Michael P. Bogenschutz, Robert Hoy, Lais F. Berro, Eduardo A. V. Marinho, Kelsy N. Areco & Michael J. Winkelman



Alcohol and tobacco substance-related disorders are a major public health problem. Despite substantial resources being invested in programs to prevent substance use and its adverse consequences, new strategies are still needed to prevent and treat substance-related disorders.

Evidence has emerged that suggests that ayahuasca, a psychedelic brew containing DMT and -carboline, may reduce substance abuse. It is used within formal religions, as well as in religious-independent contexts.

Ayahuasca has been shown to have positive effects on substance-related problems in several studies. In one study, 15 adult long-term UDV members had no current drug/alcohol-related problems, while in another study, 41 adolescents had lower past month and past year alcohol use. In a cross-sectional study, 32 Santo Daime members were evaluated and found to be free of psychiatric disorders. However, 22 participants with a previous history of drug/alcohol-related problems were in full remission.

A cross-sectional survey was conducted with 527 participants who had used ayahuasca in the past year. The results showed that ayahuasca users had less problematic use of alcohol than other psychedelic users, but more problematic use of alcohol than non-psychedelic users.

In order to contribute to the literature on the potential therapeutic effects of religious ayahuasca use on substance use disorder, we recruited volunteers from 10 Brazilian states and analyzed their substance use patterns.

Background Information: União do Vegetal

The Unio do Vegetal (UDV) is a Brazilian ayahuasca religion that uses ayahuasca in their ceremonies. It has a book edited by a sociologist member and a Scientific Commission that analyzes and authorizes studies done in the institution.

The members of the group consume ayahuasca under formal ritualized conditions. Regular sessions are held twice a month, but higher ranking members may drink it more frequently in additional closed meetings.

Ayahuasca ceremonies start at 8:00 p.m. with attendees approaching the leader (mestre) in an order of rank, waiting in line to individually receive a dose in a glass (150 – 250 ml). The ceremony lasts for 4 hours and is followed by a light meal and socializing.


A cross-sectional study surveyed 1,947 UDV volunteers in 10 Brazilian states between March 2009 and August 2011. The study tried to exhaustively survey all members attending the church.

Recruitment Procedures

We obtained preliminary authorization from UDV central leadership and approval from UDV Scientific Committee to conduct a survey in its local temples. We code numbered the volunteers’list so that personal names were separated from questionnaires in order to assure confidentiality and anonymity.

The volunteers signed a consent form that explained the voluntary nature of their participation and the confidentiality and anonymity of their information.

SAMHSA-Assessed Substance Use Disorder and WHO Criteria

The data for the comparison group for alcohol and tobacco use disorder was based on the II Household Survey on the use of psychotropic drugs in Brazil: 2005. This survey assessed a sample of 7,939 subjects throughout Brazil to estimate the Brazilian prevalence of substance use disorders.

We administered a self-report questionnaire to students about their drug use during the last 12 months and last month. The questionnaire was adapted for Brazilians and extensively used for the evaluation of patterns of drug use among Brazilian students.

Statistical Analyses

Statistical analyses were performed using IBM SPSS 20.0 for Windows. Differences were assessed between the UDV sample and Brazilian norms for lifetime use of substances and SAMSHA criteria for substance use disorder. Ayahuasca ceremony attendance variables were used to predict SAMSHA criteria for substance disorder and use of substances during the previous 30 days and previous 12 months. Multi-colinearity was assessed via Pearson’s and Spearman’s rho correlation matrixes and Variance Inflation Factor.

Sociodemographic Profile

The respondents were predominantly from the central, south and southeast regions of Brazil, were married or in a stable relationship, and had attended 34.99 ceremonies within the last year.

Lifetime use of alcohol and tobacco was higher in the UDV sample compared to the Brazilian norms for all age ranges, except for 18-24 year olds.

Hierarchical Logistic Regressions for Alcohol Use

The results show that age, gender and level of education were not significantly associated with alcohol use during the previous 12 months, previous 30 days or alcohol use disorder, but were significantly associated with alcohol use during the previous 30 days.

Participants who attended more than 3 years of UDV sessions during the previous 12 months were less likely to use alcohol during the previous 12 months, during the previous 30 days, or to meet criteria for alcohol use disorder than participants with less than 3 years of UDV membership. In Models 2, having a Bachelor’s degree increased the likelihood of using alcohol during the previous 12 months and during the previous 30 days.

Hierarchical Logistic Regressions for Tobacco Use

Age, gender and level of education explained 1.2% of tobacco use during the previous 30 days and 0.6% of tobacco use disorder, but ritual attendance was negatively correlated with tobacco use during the previous 12 months and negatively correlated with tobacco use disorder. Members with more than 3 years of UDV membership were less likely to have used tobacco during the previous 12 months, 30 days, or meet criteria for tobacco use disorder.


In this study, the largest done with ayahuasca users to date, we found that ayahuasca users had lower rates of alcohol and tobacco use disorder relative to Brazilian norms, and that ayahuasca use variables were stronger predictors of reduced alcohol and tobacco use disorders than SES variables age, gender and level of education.

Lawn et al. found that ayahuasca users had greater AUDIT-assessed problematic drinking than non-psychedelic users, which suggests that the social support system provided by church membership may be a major factor in the positive association between ayahuasca intake and substance disorder.

The design of the current study does not allow for analyses to separate the effects of religious attendance from the pharmacological effects of ayahuasca on our positive findings. However, previous studies suggest that the pharmacological effects of ayahuasca contributed substantially to these significant findings.

Possible Pharmacological Mechanisms of Ayahuasca’s Protective Effects Against Substance Abuse Disorders

Studies on ayahuasca-based substance abuse rehabilitation programs provide evidence of treatment efficacy, although these studies fall short of the ideal double-blind clinical designs. Ayahuasca’s complex and unique pharmacological profile provides multiple mechanisms through which it may exercise direct therapeutic effects for the treatment of drug dependence.

Ayahuasca produces both an increase in serotonin levels and a normalization of dopamine levels in the mesolimbic dopamine pathways, thereby treating addiction by first normalizing dopamine levels and then preventing an abrupt spike in dopamine levels that can contribute to addiction.

Ayahuasca’s effects on drug abuse may reflect the actions of its components at serotonin receptors. However, ayahuasca’s lack of abuse liability may reflect other mechanisms at play, such as the presence of 5-HT2C receptors that antagonize the effects of 5-HT2A receptor activation.

The beta-carboline alkaloids in ayahuasca stimulate the release of dopamine in presynaptic neurons, while harmine blocks dopamine reuptake into neurons at the synaptic membranes, resulting in decreases in the dopamine spiking effects that reinforce addiction.

Ayahuasca activates both 5-HT2A/2C receptor subtypes, which may explain its therapeutic effects on drug-dependence. It also may activate non-serotonergic molecular targets, which may contribute to its lack of abuse liability.

Neuroplasticity is a concept that describes the ability of neurons to alter their synaptic connections. Ayahuasca affects neuroplasticity through a variety of neurochemical mechanisms that facilitate changes in neural architecture that address the behavioral and neurochemical dynamics of addiction.

Set and Setting: Context Effects in Addressing Dependence

Ayahuasca alone may not be effective in reducing addictive behaviors, as the set and setting of the ritual are important factors. The visionary experiences of the past, combined with powerful emotional experiences, may be the key to personal transformation.

The UDV members have commented on the similar dynamics as operating in the processes of remission of drug dependence, especially as expressed in the concept of “recognition of one’s errors”. These effects may be the result of increased activation of brain areas that enhance somatic awareness, emotional arousal, emotional processing. Human imaging studies suggested that ayahuasca induces increased neuronal excitability and inhibition of top-down constraints, which allows for safe exposure to emotional events. Studies of cognitive training interventions have shown promising results in reducing drug-related effects, including motivational salience of drug-associated stimuli.

Studies suggest that religious, psychological, pharmacological, and neurophysiological mechanisms are involved in the reductions in substance dependence among UDV members. The regular group interaction is a significant feature of the social support for sobriety.

The history of drug use is significantly higher in UDV members than in Brazilian population norms, and the current status with considerably lower levels of consumption is recognized by the UDV members, who emphasize the importance of their group as a drug-treatment strategy.


Ayahuasca has been shown to reduce drug use and abuse patterns in a population sample, even though previous drug use was higher among this group prior to becoming church members.

This cross-sectional study is vulnerable to self-selection and recall biases, but has the advantage of evaluating regular ayahuasca users and analyzing the association between different degrees of ceremonial ayahuasca exposure and alcohol and tobacco use and disorder.


Each author contributed to the conception and design of the study, collected data, performed statistical analysis and interpretation, and wrote the manuscript.


We wish to thank the Centro Esprita Beneficente Unio do Vegetal, the UDV Scientific Committee, the UDV Departamento Médico Cientico (DEMEC) and the UDV volunteers for supporting the study.

Study details

Compounds studied

Topics studied
Addiction Smoking Alcohol Use Disorder

Study characteristics


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