Ayahuasca has changed countless people’s lives for the better. Just as importantly, research has shown that even long-term use of the psychedelic substance does not cause negative psychiatric or neuropsychological effects.
A number of studies conducted over the past few decades have produced evidence that ayahuasca — which is produced from plants growing in the Amazon jungle and takes its users on a psychedelic spiritual journey when ingested — does not harm the people who consume it. A 2012 study conducted by the Hospital Sant Pau in Barcelona drove home the message with scientific rigor.
The research looked at 127 people who had used ayahuasca at least twice a month for 15 years and compared them to a group who had never taken the substance. After undergoing a series of interviews and tests, the study found that there is “no evidence of psychological maladjustment, mental health deterioration or cognitive impairment in the ayahuasca-using group.” The psychedelic users even scored better in some of the cognitive tests than their counterparts.
Ayahuasca users also showed lower rates of depression, anxiety, hostility, worry and other negative traits than the control subjects, and higher in self-transcendence and spiritual orientation. “Taken together,” the study says, “the data point at better general mental health and bio-psycho-social adaptation in the ayahuasca-using group compared to the control subjects.”
Ayahuasca has been used extensively for healing and in religious ceremonies for centuries among certain groups native to the Amazon. In recent decades its popularity has been spreading elsewhere in the world and there is a growing interest in using the substance to treat mental disorders like depression, anxiety, PTSD and addiction that plague the Western world. For these treatments to gain traction, people need to be reassured that ayahuasca is safe and has few or no major side effects.
The 2012 study goes a long way in that regard, because it used a larger sample size than previous research, conducted an extensive array of tests and followed up its results with another round of testing a year later. Throughout all, the evidence remained consistent: ayahuasca does not cause long-term harm to its users.
The study was funded by the International Center for Ethnobotanical Education, Research & Service, or ICEERS. Although there is no specific evidence of harm, ICEERS recommends that people with heart conditions and people who take serotonin-related drugs like antidepressants avoid ayahuasca as a precaution.
The 2012 study does caution that there was a certain amount of self-selection when it came to the subjects — anyone who had experienced harm from ayahuasca would presumably not continue to take it consistently for fifteen years. However, the science on how the substance works on the brain corroborates reports of beneficial results. Ayahuasca allows the brain to bypass its built-up pathways, meaning, for example, that people are able to overcome ingrained responses to a stimulus based on past trauma. Users are actually able to reset some of the brain’s connections to heal past wounds, in other words.
Key to the healing effects may also be the way the substance is administered in traditional ceremonies. “It’s not the ayahuasca,” psychiatrist and addiction expert Dr. Josep Fabregas said in a documentary about the psychedelic. “It’s the ritual use of ayahuasca.” In any event, it seems clear that when it comes to ayahuasca treatments, practitioners can rest assured that they are observing the first rule of medicine — do no harm.