Depressive DisordersSubstance Use Disorders (SUD)Personality & Trait FactorsAyahuasca

Psychological and neuropsychological assessment of regular hoasca users

This study (n=57) assessed the socio-economic status, mood, personality traits, impulsiveness, drug use, quality of life, extrinsic and intrinsic religiosity, and neuropsychological function of ayahuasca users and non-users. The findings indicate that religious use of ayahuasca does not adversely affect neuropsychological functioning and may have positive effects on substance abuse and mood.

Authors

  • Michael Bogenschutz
  • Rick Strassman
  • Draulio Silveira

Published

Comprehensive Psychiatry
individual Study

Abstract

Background

Hoasca (also called ayahuasca) is a N,N-dimethyltryptamine (DMT) - containing psychedelic brew originally used for magico-religious purposes by Amerindian populations of the Amazon Basin. Recently, Brazilian syncretic churches have helped spread the ritual use of hoasca to Western societies. The aim of this study was to evaluate substance use, and neuropsychological and psychological functioning of regular hoasca users within a religious setting.

Methods

Assessment of socio-economic status, mood, personality traits, impulsiveness, drug use, quality of life, extrinsic and intrinsic religiosity, and neuropsychological function was performed on 30 volunteers from a U.S. branch of União do Vegetal (UDV), a Brazilian religion which uses hoasca ritually. We also assessed 27 non-hoasca-using control subjects matched by socio-demographic profile and church attendance. Mann-Whitney U, chi-squared and Fisher tests were used to analyze differences between groups. Spearman's association and simple logistic regression tests were used to analyze the impact of frequency of hoasca use on dependent variables.

Results

Relative to the control group, the UDV group demonstrated lower scores for depression (p = 0.043, r = .27) and confusion (p = 0.032, r = .29) as assessed by the Profile of Mood States (POMS); higher scores on the instrument Big Five Inventory (BFI) for the personality traits agreeableness (p = 0.028, r = .29) and openness (p = 0.037, r = .28); higher scores on the quality life domain role limitations due to physical health as determined by the instrument Medical Outcomes Study Short Form-36 - SF-36 (p = 0.035, r = .28); less recent use of alcohol (p < 0.001, φc = .57), greater past use of alcohol to intoxication (p = 0.007, φc = .36) and past use of cannabis (p = 0.001, φc = .45) as measured by the Addiction Severity Index (ASI), 5th edition; better score on a measure of memory vulnerability to proactive interference as measured by the California Verbal Learning Test - CVLT (p = 0.040, r = .27). Lifetime use of hoasca was positively correlated with role limitations due to physical health (p = 0.032, rs = .39) and negatively associated with lifetime heavy alcohol use (p = 0.034, OR = 0.979).

Conclusions

The findings indicate that religious use of hoasca does not adversely affect neuropsychological functioning and may have positive effects on substance abuse and mood.

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Research Summary of 'Psychological and neuropsychological assessment of regular hoasca users'

Introduction

Hoasca (also called ayahuasca) is a decoction combining Psychotria viridis, which contains N,N-dimethyltryptamine (DMT), and Banisteriopsis caapi, which contains β-carbolines that act as monoamine oxidase inhibitors and render DMT orally active. Acute ingestion produces dose-dependent perceptual, cognitive and affective effects that peak within about 60–120 minutes and largely resolve within 4–6 hours. Interest in the brew has spread beyond Amazonian magico-religious contexts to syncretic Brazilian churches such as União do Vegetal (UDV) and to non-religious users worldwide, prompting regulatory and scientific attention to possible long-term psychological and neuropsychological effects of repeated ritual use. Cesar and colleagues designed a cross-sectional, case-controlled study to evaluate whether regular, ritualised hoasca use within a UDV congregation in the United States is associated with differences in substance use, mood, personality, quality of life, religiosity, and neuropsychological functioning. The study aimed to address a gap in prior research by matching hoasca users to controls on socio-economic status and church attendance, thereby attempting to separate effects of the substance from effects associated with organised religion and communal support.

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Study Details

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