The internet is full of articles citing research papers, but often the public does not see the full scientific process behind the quick quotation or conclusion. The current psychedelic renaissance has inspired a resurgence of psychedelic research on a variety of formally stigmatized substances including LSD, psilocybin and ketamine. Ayahuasca is a recent target of clinical researchers looking for alternative treatment approaches to addiction, anxiety and depression. The following exploration highlights the findings of the Global Ayahuasca Project’s longitudinal study. Ayahuasca use and reported effects on depression and anxiety symptoms: An international cross-sectional study of 11,912 consumers. Understanding the process behind clinical ayahuasca research can better help audiences interpret the various messages and conclusions of psychedelic studies.
Background and Introduction
Previous studies and cultural shifts often inspire new researchers to further explore topics. The background and introduction section of this study outlines why the researchers are looking into ayahuasca use and its effects on anxiety and depression. Let’s explore why these researchers set out on this journey.
The roots of the psychoactive brew ayahuasca lie in the spiritual practices of ancient Amazonian tribes. A number of Brazilian syncretic religions, specifically Santo Daime and Uniao de Vegetal, have gained many new members since the 1980s including influxes of Europeans, Americans and Australians seeking to take part in their sacred ayahuasca ceremonies. In recent years, ayahuasca ceremonies have left the jungles of the Amazon and now take place across the globe.
The Western world’s increasing interest in ayahuasca has spurred clinical researchers to examine how its active compounds — namely Dimethyltryptamine (DMT) and β-carboline alkaloids — affect mood and addiction. Research has included open-label and double-blind trials looking into ayahuasca’s antidepressant and anti-addictive effects. Open-label trials are conducted with both study participants and researchers having full awareness of which treatment is administered and the goals of the trial. Double blind trials operate with neither the participants or researchers knowing who is receiving treatment or placebo.
These trials inspired 13 researchers to come together and create an international longitudinal analysis of ayahuasca’s benefits.
So how did the study work? The methods section describes how the research team went about gathering data and who was involved in the process. Let’s get into the specifics.
Based at the University of Melbourne, an international group of multidisciplinary researchers came together to form the Global Ayahuasca Project and started the first-ever global survey of ayahuasca drinkers. The GAP collected data from 11,912 survey participants from 2017 to 2020. This research paper focuses on the subsample of participants who reported depression or anxiety diagnosis at the time of their ayahuasca ceremony.
Participants took part in an online survey developed from existing ayahuasca research and psychological survey tools. Researchers collaborated with leaders in ayahuasca-using churches to ensure efficacy in their measurements. The survey was made available on LimeSurvey in English, Brazilian Portuguese, Spanish, Czech, German, and Italian.
Email invitations to the survey were distributed to ayahuasca-related organizations, online forums and posted on flyers at conferences and lectures. Participants were not given any financial incentives and the data was cross-checked for repeat and incomplete survey responses. The survey was also approved by the Melbourne University Health Research Committee for further efficacy validation.
Researchers employed the Kessler-10 Psychological Distress Scale to measure levels of depression and anxiety, with higher scores indicating worse mental states. The Kessler scale is a set of 10 questions intended to measure the anxiety and depressive symptoms a person has experienced in the last month. This was how they established the baseline levels of anxiety or depression and tracked improvements in participants after their ayahuasca ceremony.
In order to measure the participant’s levels of spiritual significance, researchers employed the Persisting Effects Questionnaire, a six-point scale pioneered by psilocybin researchers. The six points range from “not at all significant” to “most spiritually significant experience of my life.”
They also used the Short Index of Mystical Orientation, a scale already utilized in research on Catholic priests. The mystical measurements were also greatly influenced by ayahuasca literature and neo-shamanic practitioners surveyed during the background research for this study.
Several customized questions were added to account for the unique experience of an ayahuasca ceremony, measuring things like the number of insights, understanding patterns and dynamics in your intimate relationships and an increased sense of connection to the natural world.
So, where do the statistics come from? The data section turns the survey responses into usable numerical form. In order to learn from the participants, the researchers have to apply the statistical tools available to them. Let’s take a look at how they used those tools.
The information garnered from the survey responses was put through independent sample t-tests and Mann-Whitney U tests to ensure the distribution of data was normal. A normal distribution means the data fit on a bell curve and has more scores concentrated in the middle of the spectrum and fewer on the extremes.
This is the ideal form of data for mathematical statisticians to work with because they can manipulate the data easily and measure the standard deviation of a group. A normal distribution of data is a fixture of many psychological, physical and biological measurements making it an important thing for these researchers to establish in their exploration of ayahuasca’s antidepressant and anxiolytic effects.
The research team also used proportional odds models to assess the associations between demographic and ayahuasca-induced variables. Proportional odds models are built on ordinal regression and allowed the researchers to establish a single regression coefficient to estimate each demographic or environmental predictor.
In order to analyze the participant’s response to the Kessler-10 scale, the statisticians used linear regression analysis. Data needs to meet certain parameters to fit into a linear regression model and these survey responses fell into a satisfactory distribution.
The results section is often the only portion highlighted in internet articles. Of the subsample, 1571 participants reported issues with depression and 1125 reported struggling with anxiety at the time of their ayahuasca consumption. Based on the Kessler-10 scale, of the participants dealing with depression, 46% reported their symptoms “very much improved” and 32% deemed their depression as “completely resolved.”
For survey participants who reported dealing with anxiety, 54% said their symptoms were “very much improved” and 16% said their anxiety was “completely resolved.”
More drastic symptom improvement was associated with a number of environmental factors like: “subjective mystical experience, a number of ayahuasca sessions and the number of personal insights experienced.” Researchers found that the depression and anxiety subgroup reported higher scores on the Short Index of Mystical Orientation and Persisting Effects Questionnaires.
Researchers were curious if the severity of mental health influenced participants’ likelihood to have drastic mental shifts. They found that the participants who experienced more relief from anxiety symptoms were not in dramatically different places at the time of their ceremonies, but for the depression group, the mindset going into had a borderline effect on perceived benefits post-ceremony. They urged for more research in this area in order to find more conclusive answers.
Not all participants reported improvements: 2.7% and 4.5% of ayahuasca drinkers reported their depression or anxiety symptoms as worsened. Participants who reported a negative experience often had difficulties with integrating their experiences and assimilating back into their normal life in the following weeks. Participants were more likely to experience a worsening of symptoms after ayahuasca consumption if they went into the ceremony feeling: disconnected, nervous or hopeless.
Any study is a sample of people and it is incredibly challenging to account for all variables and apply the findings to a general population. The limitations section of this research paper outlines where the study could have fallen short and how further studies could address these challenges. Let’s take a look.
This longitudinal study is a cross-sectional analysis, meaning it cannot provide evidence of the efficacy of ayahuasca treatments. Cross-sectional analysis studies like this one, generally cannot provide evidence of a relationship between an exposure — in the case of ayahuasca and the outcome — a reduction or increase in anxiety or depression symptoms.
Another limitation of this study is the potential for selection bias. Selection bias is a phenomenon where study participants do not represent the population of interest. In this study, survey-respondents with positive ayahuasca experiences may have been biased towards participation. If the study participants have positive bias then any conclusions from this sample cannot speak for a more general population.
Discussion and Conclusion
The final section of a research paper is the discussion and conclusion. Here the research team lays out general findings and outlines their recommendations for further research.
Overall, this study concluded that ayahuasca drinkers reported perceived benefits in their anxiety and depression symptoms based on survey analysis. The naturalistic setting and ceremonial significance of the traditional healing model may have influenced these outcomes, though more research is needed. They recommend an exploration of ayahuasca’s perceived benefit in a more controlled setting before recommending its efficacy as a clinical treatment.
Hopefully, this exploration has de-mystified the research process and give readers more tools for critical engagement with scientific materials. Let us know in the comments below if you have any insights you would like to add to the conversation.