Ayahuasca

Key Insights

• Ayahuasca has been used in Latin America for over 1000 years and has been found to be helpful for treating a variety of mental health and substance use disorders. The setting often involves elaborate rituals which can add to the therapeutic effects of ayahuasca.
• Only a few clinical trials have been done with ayahuasca, one of which showed improvements in treatment-resistant depression. The lack of clinical studies is holding back the wider adoption of this psychedelic.
• Ayahuasca is not a scheduled drug under the United Nations conventions, but its main component DMT is. This has allowed the plants, and their use, to escape regulation based on their natural occurrence. Other exemptions have been made on religious grounds in the US, Canada and beyond.

Author: Floris Wolswijk is the founder of Blossom. He started Blossom in 2019 to help translate psychedelic research to a broader audience. Since then, he has grown the database to encompass 2000 papers and hundreds of other valuable resources. Floris has an MSc in Psychology and offers psychedelic-assisted coaching at FLO.

Ayahuasca is served as tea, made from a blend of different plants, usually, the Banisteriopsis Caapi (ayahuasca or yagé) vine and Psychotria Viridis (chacruna) shrub, which contains DMT. Pharmahuasca is the name for the pharmaceutical version, which combines an MAOI (which prevents the stomach from breaking down DMT) with DMT. Because the name ‘ayahuasca’ denotes the brew used in traditional settings, some variations of it work via other compounds and do not contain DMT. Ayahuasca has been used for more than a thousand years and many observational studies have found positive effects on mental health and substance use disorders, though clinical studies are severely lacking.

Clinical trials and research

Ayahuasca is the topic of more than 160 papers in Blossom’s research database, but at this time there have only been three clinical trials completed with the brew. The varying amounts of the different ingredients in the brew make it difficult to study in controlled settings. The setting itself is also, just like with traditional psilocybin use, a big part of ayahuasca’s healing power and something not suitable for controlled clinical studies. That being said, ayahuasca has been studied for a wide range of mental health disorders. The following is a list of conditions for which ayahuasca has potential therapeutic benefits based on clinical trials and academic studies conducted to date:

• Depression, MDD and TRD
• PTSD
• Substance misuse, including alcohol, opioid, cocaine and nicotine dependence
• Eating disorders such as anorexia nervosa

While ayahuasca has been in use for at least a thousand years and is commonly taken in modern ritual settings, there is very little clinical data on the substance. The only phase II clinical trial, with 29 patients and completed in 2019, investigated ayahuasca for the treatment of TRD. The double-blind controlled study conducted at the Onofre Lopes University Hospital in Brazil, found significant reductions in depressive symptoms one day after treatment. The response rate of patients was significantly higher in the ayahuasca group (64% versus 27% in the placebo group). Most studies of ayahuasca are taking place in Latin America.

Latin America

A 2016 study followed a group of 17 participants with recurrent depression who were given ayahuasca in a medical setting (leaving out many of the characteristics of the ‘set’ and ‘setting’). The researchers at the University of São Paulo thus investigated the pharmacological effects of ayahuasca outside the
traditional context. The study found significant improvements in depression and suicidal ideation. A follow-up, five years later, reported that participants found the experience valuable, but no long-lasting effect on mental health was reported.

Adverse events during and after the use of psychedelics is a valid concern that deserves much attention if psychedelics are to become medicines. Because of the observational nature, often without a screening of participants on pre-existing mental health disorders, research in this area is still limited. Researchers at the Universitat Rovira found this year that up to 17% of first-time ayahuasca users had experienced acute psychological adverse events. Some of these were ascribed to an unsafe environment. On average, even these participants had improved mental health scores six months after the study.

North America

An observational study conducted by the University of Victoria researchers followed 12 participants who participated in two ayahuasca ceremonies with the goal of reducing addictions. The self-reported problematic use of cocaine, alcohol and tobacco decreased significantly in the six months after treatment. These and several other studies have found positive effects of ayahuasca on a variety of addictions.

Europe

Researchers at Maastricht University have recently completed an interesting study on the effects of ‘set and setting’ in ayahuasca retreats throughout Europe. As in other studies, they found improvements in the mental health of the participants but found that on most measures the participants in the placebo group, who did partake in the ceremony, received similar benefits. This highlights the importance of non-pharmacological factors, not only in research on ayahuasca but also in the ‘set and setting’ in which other psychedelics are administered.

Several studies, one of which by a Spanish research group, has found the components of ayahuasca, specifically DMT, lead to restoration and possibly the growth of new neuronal cells. Although these studies are still in the early phases, now being conducted in mice, they may have large implications for those suffering from Alzheimer’s and traumatic brain injury (TBI).

Legality of ayahuasca worldwide

The principal component of ayahuasca, DMT, is a Schedule I drug under the Convention on Psychotropic Substances, but the plants that contain DMT are not subject to international control. This exemption, which also applies to peyote and psychoactive mushrooms that contain mescaline and psilocybin respectively, means that there is less top-down regulation regarding the use and distribution of ayahuasca. Throughout Latin America, there is little to no enforcement of any restrictions on the use of ayahuasca.

Another route through which ayahuasca is available is through religious exemptions. The Religious Freedom Restoration Act has allowed groups like the União do Vegetal to import and use ayahuasca as their sacrament. The Santo Daime church has won similar cases and can use ayahuasca in both the US and Canada for religious purposes.