Acute and subacute effects of a single dose of ayahuasca on the recognition of facial expressions of emotions

Author(s)

Juliana Mendes Rocha

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2020-02-03

Examining board members

Jaime Eduardo Cecilio Hallak; Dráulio Barros de Araújo; Sergio Sheiji Fukusima

• Advisor: Jaime Eduardo Cecilio Hallak; Rafael Guimarães dos Santos

Abstract

Several psychiatric disorders, like anxiety disorders, depression, psychotic disorders and others are associated with deficits in social cognition and recognition of facial expressions. In addition, available pharmacological treatments do not work for a significant portion of these patients and produce several side effects. Ayahuasca is a psychoactive drink traditionally used by indigenous Amazonian groups for therapeutic purposes. Animal and human studies suggest that ayahuasca has anxiolytic and antidepressant effects with good tolerability. The aim of this project was to evaluate the subjective effects of a single dose of ayahuasca and its effects on the recognition of emotions in facial expressions. 20 healthy volunteers were included in the study (randomized, double-blind and placebo-controlled). Acute assessment (0-6 h) was performed by applying the Visual Analog Mood Scale (VAMS), Body Symptom Scale (BSS), Beck Anxiety Inventory (BAI), and recognition of emotions in facial expressions (REFE) test. Acute tolerability was assessed by cardiovascular measurements and reports from volunteers. We also measured brain derived neurotrophic factor (BDNF) plasma levels during the experimental session to evaluate the effects of ayahuasca on neurotrophins. Moreover, we assessed personality before (basal/ T1) and 3 months after the experimental session (NEOFFI). SSS was also applied 24 hours after the experiment (D1), and BAI and REFE tests were applied on days D1, D7, D14 and D21 and 3 and 6 months after the experimental session. Compared to placebo, ayahuasca significantly increased the scores of the VAMS cognitive impairment factor and of the SSS. No significant effects were observed on the other variables, although visual inspection of the graphs indicates a possible acute reduction in BDNF and anxiety throughout the study (BAI). Ayahuasca was well tolerated, producing mainly nausea, gastrointestinal discomfort and vomiting. Further studies involving a larger number of subjects are needed to confirm the data of the present study. (AU)

• FAPESP's process: 17/24791-8 - Acute and subacute effects of a single Ayahuasca dose in the recognition of facial expressions
• Grantee: Juliana Mendes Rocha
• Support Opportunities: Scholarships in Brazil - Master