1996 – Psychology Study Suggests Long-term Benefits of Ayahuasca
Ayahuasca has a long history of use by indigenous peoples in the Amazon basin, in both a shamanic context and by members of churches dedicated to its use. Many such people who use ayahuasca consume the brew throughout their lives, confident that this provides life-changing benefits. But what exactly are these long-term benefits, if any? This is what a team of researchers sought to answer.
Charles Grob, Dennis McKenna, and other researchers carried out a psychological study on the effects of ayahuasca. They recruited two groups of people from the city of Manaus, located in the Brazilian Amazon. The first group was made up of 15 long-term users of ayahuasca from the União de Vegetal (Union of the Plants, or UDV), a syncretic religious movement that was founded in 1961 in the Brazilian Amazon. Its members ritually consume ayahuasca – or hoasca tea as it’s referred to – as it is viewed as a religious sacrament. The second group was made up of matched controls (people from the same community with no prior ayahuasca use). The researchers assessed the participants using psychiatric diagnostic interviews, personality surveys, and neuropsychological tasks.
While the sample size was very small, UDV members scored significantly higher in measures of “confidence”, “regimentation” (strict control of behaviour), and “reflection” (more thoughtful than impulsive). UDV members were also found to display a range of personality traits, including orderliness, persistence, emotional maturity, stoicism, frugality, loyalty, tranquility, higher energy, fewer inhibitions, more optimism, and higher social desirability and outgoingness. In contrast, the control group scored higher on traits like novelty-seeking, which means these participants were more likely to seek out new experiences, be impulsive, and be quick to lose their temper. The researchers conducting this study wanted to find out if – and to what extent – ayahuasca use could be responsible for UDV member’s positive psychological scores and mental well-being.
During interviews, the researchers found that some UDV members had histories of alcohol abuse, depression, or anxiety before they joined the ‘ayahuasca church’. But, all of these problems seemed to have stopped following ayahuasca use and didn’t show up again. Those who abused alcohol or suffered from alcoholism quit drinking for good after joining UDV, whereas those who had issues with depression or anxiety no longer experienced symptoms of these conditions as members of the ayahuasca church. Also, the researchers point out that the mental health of these members improved without any signs of personality or cognitive abilities being negatively affected by the ayahuasca use.
All members spoke about their ritual use of ayahuasca within UDV as having had a profound impact on their lives. A common theme was a belief that their ayahuasca experiences showed them the negative consequences of their approach to life and this motivated them to make radical and positive changes to both their attitudes and behaviour. Although UDV members strongly believed their ayahuasca use caused these changes, it’s important to note that these shifts could also be attributed to membership of the UDV community itself. After all, a large body of research has shown that belonging to a religious community can have a positive impact on one’s attitudes and psychological health. This is due to the strong support system and the sense of meaning that religious affiliation can afford its members.
Another interesting finding from this study was that UDV members scored significantly higher on neuropsychological testing, specifically on tests that rated the participants’ ability to learn, memorise, and recall information. The UDV members claim ayahuasca had helped to improve their concentration and memory. However, the researchers can’t be sure that these differences are down to ayahuasca. You would have to assess a member’s cognitive abilities before any ayahuasca experience and then compare this with the scores measured after ayahuasca use. There could be other factors at play that help to explain why UDV members scored higher in some areas of cognition than their counterparts who weren’t UDV members and who hadn’t used ayahuasca.
Ayahuasca use is widespread among urban and rural indigenous groups of the Amazon and members of syncretic churches found in Brazil, such as the UDV and the Santo Daime. But despite this, few rigorous scientific studies had been carried out into the effects of ayahuasca before the 1990s. This study from McKenna, Grob, and others was an attempt to apply contemporary research models and tools to the ceremonial use of ayahuasca. The researchers emphasize that until this study, medical and psychiatric researchers hadn’t addressed the effects of this brew. They also conclude by saying that “the ceremonial use of hoasca…is clearly a phenomenon quite distinct from the conventional notion of “drug abuse””. The apparent “positive and therapeutic” effects of hoasca show, instead, that the complete opposite holds true. Moreover, the authors of the study remark on the growing interest in ayahuasca in North America and underscore that this should motivate further research into how this psychedelic brew can be used as safely as possible and minimize the risk of adverse effects.
The research represents one of the first scientific investigations of ayahuasca as medicine. Since its publication, there have been many more, including by neuroscientists studying ayahuasca visions and brain function and psychiatrists analyzing more information about the positive long-term effects of ayahuasca on health. This burst of research coincided with the global popularizing of ayahuasca in the 1990s by the mesmerizing talks of philosopher Terence McKenna and anthropologist Jeremy Narby’s illuminating book The Cosmic Serpent. By 2015, underground groups started advertising ayahuasca ceremonies in the United States despite being illegal. Today, the brew continues to expand around the globe with retreat services offered across South America, North America, Europe, Australia, and elsewhere, and with many new research project underway.
Grob, C. S., McKenna, D. J., Callaway, J. C., Brito, G. S., Neves, E. S., Oberlaender, G., … & Strassman, R. J. (1996). Human psychopharmacology of hoasca, a plant hallucinogen used in ritual context in Brazil. The Journal of Nervous and Mental Disease, 184(2), 86-94.