A single dose of ayahuasca improves self-perception of speech performance in socially anxious people, study finds
The psychedelic brew known as ayahuasca could help improve the self-perception of those with social anxiety disorder, according to a controlled proof-of-concept study recently published in the Journal of Clinical Psychopharmacology.
Ayahuasca, a concoction used for centuries by indigenous Amazon tribes, contains the powerful psychedelic drug dimethyltryptamine (DMT) and monoamine oxidase inhibitors. Preliminary research has offered some evidence that ayahuasca provides psychological benefits for individuals suffering from anxiety and depression.
“Social anxiety disorder is a prevalent, under-diagnosed, anxiety disorder with limited treatment options,” said study author Rafael Guimarães dos Santos, a postdoctoral fellow at the Ribeirão Preto Medical School at the University of São Paulo.
“Social anxiety disorder is characterized by anxiety during social events, such as public speaking, eating, and talking to other people. Also, social anxiety patients show a negative bias toward their social performance: they believe their performance will be ineffective, limited, and will be judged by other people.”
“In some cases, this could lead to avoidance of the social situation, and certainly interfere with the daily activities of these patients,” dos Santos said. “Ayahuasca, besides having antidepressant and anxiolytic potentials, could (maybe) change this negative cognitive bias, since its performance-enhancing properties have been described anecdotally.”
In the double-blind study, 17 volunteers who had been diagnosed with social anxiety disorder were randomly assigned to an ayahuasca treatment group or a placebo group. The researchers followed a careful screening process, which excluded potential volunteers with previous experience with ayahuasca; a current or past history of cardiovascular, liver, or neurological diseases; a current psychiatric diagnosis (except for anxiety disorders); a current use of any psychiatric medication; and a recurrent use of drugs of abuse.
After receiving a dose of ayahuasca or placebo, the volunteers remained seated in a comfortable reclining chair and were instructed to “remain as quiet and introspective as possible, with your eyes opened or closed, while focusing on your body, thoughts, and emotions.” About five hours later, after the acute effects of the drug had worn off, the volunteers completed an anxiety-inducing public speaking test, in which they were given two minutes to prepare a four-minute speech in front of a camera.
“The task we used is a validated measure to induce anxiety and to assess the volunteers’ performance,” dos Santos said.
The researchers did not find a statistically significant reduction in subjective anxiety symptoms in those who ingested ayahuasca compared to those who had ingested the placebo. “The sample size was small, and volunteers had a low baseline anxiety level. Thus, some non-significant results could be the result of these factors,” dos Santos explained.
But ayahuasca ingestion was associated with improvements in self-perception of speech performance.
“We showed that a single dose of ayahuasca improved the self-perception of performance during a public-speaking task, which is usually associated with poor performance by social anxiety patients. Moreover, ayahuasca was well tolerated in this population, opening the door for further clinical trials in this and other anxiety disorders. This is the first controlled trial of a classic hallucinogen in this population,” dos Santos told PsyPost.
The most significant adverse effects reported by the volunteers were transient gastrointestinal discomfort and nausea, vomiting, drowsiness, confusion, and headache.
In the current study, along with a similar one published this year, the researchers also examined whether ayahuasca influenced the recognition of facial expressions. Volunteers completed a computerized task in which they were shown human faces and asked to identify whether happiness, sadness, fear, disgust, anger, or surprise was being expressed.
“There is evidence that some psychiatric disorders, such as mood and anxiety disorders, are characterized by deficits in the recognition of facial expressions of emotions. For instance, depressed individuals may show a negative, biased pattern where happy and neutral faces are recognized as negative (fear/sad) faces,” dos Santos explained.
“And there is also evidence that some antidepressant drugs may improve that deficit. Since ayahuasca has antidepressant effects, and since previous studies with LSD in healthy individuals has shown reduced recognition of faces of fear, we wanted to explore if in healthy individuals (first) ayahuasca could modulate face recognition.”
But neither study found evidence that ayahuasca ingestion had an impact on the recognition of facial expressions.
While it is possible that ayahuasca doesn’t affect face recognition, the lack of significant effects could also be the result of methodological issues. “The limited sample size could have precluded a significant result, and we observed that the alkaloids in natural ayahuasca (specially DMT) degrades over time. Thus, the small sample plus alkaloid degradation could have precluded a significant result,” dos Santos said.
“Moreover, we applied the face recognition task several times (before and during the task, and up to three months afterwards), so volunteers could have learned the task, which would also make it difficult to find significant differences between ayahuasca and placebo.”
Despite the limitations, the new studies included several methodological improvements over past research.
“It is important to note that these trials were parallel-group, placebo-controlled trials with naïve ayahuasca users,” dos Santos said. “Previous studies were mostly open (non-placebo-controlled) or crossover trials (where individuals take one treatment and then are crossed to the other arm of the trial), with individuals with previous experience using hallucinogens. Parallel-group, placebo-controlled trials with naïve users seem to be more appropriate to investigate these drugs, since their psychological effects are difficult to mask.”
The study, “Ayahuasca Improves Self-perception of Speech Performance in Subjects With Social Anxiety Disorder“, was authored by Rafael G. dos Santos, Flávia de Lima Osório, Juliana Mendes Rocha, Giordano Novak Rossi, José Carlos Bouso, Lucas S. Rodrigues, Gabriela de Oliveira Silveira, Mauricio Yonamine, and Jaime E. Cecílio Hallak.
The study, “Effects of Ayahuasca on the Recognition of Facial Expressions of Emotions in Naive Healthy Volunteers“, was authored by Juliana Mendes Rocha, Giordano Novak Rossi, Flávia de Lima Osório, José Carlos Bouso, Gabriela de Oliveira Silveira, Mauricio Yonamine, Alline Cristina Campos, Giuliana Bertozi, Jaime E. Cecílio Hallak, and Rafael G. dos Santos.