The “Hoasca Project” is the most comprehensive, in-depth scientific study that has been done on ayahuasca and mental health. It was carried out by an international team of researchers from the United States, Brazil and Finland. Several articles were published as a result of this study. One article, entitled “Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges”, highlights some of the findings of the study with respect to the effects of ayahuasca on mental well-being and addiction. The study had four primary objectives:
1. To assess the acute psychological and physiological effects of ayahuasca in human subjects
2. To assess the effects of ayahuasca on serotonin receptors in long-term drinkers of ayahuasca tea
3. To determine the active constituents of ayahuasca tea in plasma
4. To determine the active constituents of ayahuasca tea
The first two objectives are of particular interest for those that are considering ayahuasca as a cure for depression, alcoholism, and other substance abuse and mental health issues. The researchers selected 15 healthy male subjects that had attended services at the Uniao do Vegetal (UDV) church in Manuas, Brazil, for at least 10 years and consumed ayahuasca tea an average of once every two weeks. The subjects did not consume alcohol, tobacco or any other drugs. For the control group, the researchers selected a healthy group of 15 male subjects that were similar in age, socioeconomic status and had similar diets to the other group. None of the subjects in the control group had ever consumed ayahuasca tea and they were not members of the UDV church.
With respect to the psychological effects of the tea, the researchers found that the ayahuasca drinkers had “a trend towards greater reflection versus impulsivity” and they had “significantly greater confidence versus fear of uncertainty and trends toward greater gregariousness versus shyness and greater optimism versus anticipatory worry”.
The results found in interviews with the subjects were very impressive:
“The most striking findings of the psychological assessment came from the structured diagnostic interviews and the semistructured, open-ended life story interviews. The Composite International Diagnostic Interview was used for the structured diagnostic interview. None of the UDV subjects had a current psychiatric diagnosis, whereas 2 of the control subjects had an active diagnosis of alcohol misuse and hypochondriasis. Only 1 subject among the controls had a past psychiatric disorder that was no longer present; an alcohol misuse disorder that had remitted 2 years previously. However, prior to membership in the UDV, 11 of the UDV subjects had diagnoses of alcohol misuse disorders, 2 had past major depressive disorders, 4 had past histories of drug misuse (cocaine and amphetamines), 11 were addicted to tobacco, and 3 had past phobic anxiety disorders. Five of the subjects with a history of alcoholism also had histories of violent behavior associated with binge drinking. All of these pathological diagnoses had remitted following entry into the UDV. All of the UDV subjects interviewed reported the subjective impression that their use of hoasca tea within the context of the UDV had led to improved mental and physical health and significant improvements in interpersonal, work, and family interactions.”
With respect to ayahuasca’s effect on serotonin, the researchers found a significant increase in the density of serotonin transporter sites in ayahuasca drinkers compared to the control group. No other pharmacological agent is known to have this effect on serotonin. This has potentially profound implications for the treatment of depression and addiction if further, in-depth studies of ayahuasca and mental health can reinforce this conclusion. The current paradigm of treatment with antidepressant medications has limited effectiveness for many people and an array of side effects that are often undesirable. Furthermore, from personal experience, I can say that the effectiveness of antidepressant medications often decreases over time and when one stops taking these medications there are terrible withdrawal effects that make coping with everyday stressors very challenging. Issues with mental health have plagued humans for ages. They are one of the most pervasive diseases in the modern world. This study suggests that we have much to learn from plants and that there is great value for our health in preserving forests that hold such miraculous medicines.
Excerpt taken from McKenna, Dennis J. 2004. “Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges.” Pharmacology and Therapeutics, Issue 102, pp. 11-129.