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Rafael G. Dos Santos

Universidade de São Paulo, Clinics Hospital of Ribeirão Preto

90 papers in the library · 5,039 citations · publishing 0-2026

Papers

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Underground ibogaine use for the treatment of substance use disorders: A qualitative analysis of subjective experiences.

Drug and Alcohol Review February 1, 2023 Borja J Rodríguez-cano, Maja Kohek, Genís Ona et al. 17 citations

Ibogaine is one of the alkaloids naturally found in plants such as Tabernanthe iboga, which has been traditionally used by members of the Bwiti culture. Since the discovery of its anti-addictive properties by Howard S. Lotsof in 1962, ibogaine has been used experimentally to treat substance use disorders (SUD), especially those involving opioids. We aim to provide a detailed understanding of...

DOI: 10.1111/dar.13587 (opens in new tab) Full text (opens in new tab) Psychedelic-assisted therapy Hallucinogenic Qualitative analysis Substance use disorders +15

The effects of ketamine and classic hallucinogens on neurotrophic and inflammatory markers in unipolar treatment-resistant depression: a systematic review of clinical trials.

European Archives of Psychiatry and Clinical Neuroscience February 1, 2023 Giordano Novak Rossi, Jaime E. C. Hallak, Glen B. Baker et al. 14 citations

Although results are still preliminary, ketamine and classical hallucinogens have shown promise in recent years as novel, fast-acting antidepressants, especially for the treatment of unipolar treatment-resistant depression (TRD). Depression also seems to be related to abnormal levels of peripheral inflammatory and neurotrophic biomarkers, which may one day help to diagnose of this disorder. In...

Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant

Biomolecules November 2, 2022 Giordano Novak Rossi, Lorena T. L. Guerra, Glen B. Baker et al. 29 citations

Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic...

DOI: 10.3390/biom12111618 (opens in new tab) Ayahuasca Antidepressant Hallucinogen Pharmacology +1

Tripping to Cope: Coping Strategies and Use of Hallucinogens during the COVID-19 Pandemic in Three Cultural Contexts

Psychoactives September 2, 2022 Genís Ona, Dóra Révész, Maja Kohek et al. 9 citations

The COVID-19 pandemic has made evident the need to develop effective strategies to cushion the psychological consequences of social catastrophes. Preliminary evidence suggests that the use of hallucinogens is a protective factor that mitigates against such stressors. However, the underlying mechanisms must be further explored. This study specifically focused on the potential role of coping...

DOI: 10.3390/psychoactives1010003 (opens in new tab) Hallucinogen Coping psychology Disengagement theory Pandemic +5

Effects of ayahuasca and its alkaloids on substance use disorders: an updated (2016-2020) systematic review of preclinical and human studies.

European Archives of Psychiatry and Clinical Neuroscience June 1, 2022 Lucas Silva Rodrigues, Giordano Novak Rossi, Juliana Mendes Rocha et al. 48 citations

Ayahuasca is a hallucinogenic/psychedelic traditionally used for ritual and therapeutic purposes. One such therapeutic use is related to Substance Use Disorders (SUDs). A previous systematic review of preclinical and human studies published until 2016 suggested that ayahuasca and its alkaloids have therapeutic effects in the treatment of SUDs. To conduct an update of this previous review. A...

The adverse events of ibogaine in humans: an updated systematic review of the literature (2015-2020).

Psychopharmacology June 1, 2022 Genís Ona, Juliana Mendes Rocha, José Carlos Bouso et al. 41 citations

Ibogaine is the main alkaloid of the African shrub Tabernanthe iboga. It produces hallucinogenic and psychostimulant effects, but it is currently known for the anti-addictive properties. Despite the potential therapeutic effects, several cases of fatalities and serious adverse events related to ibogaine/noribogaine use can be found in the literature. Most studies consist in case reports or were...

DOI: 10.1007/s00213-021-05964-y (opens in new tab) Full text (opens in new tab) Adverse events Drug interactions Ibogaine risks Noribogaine safety +12

Ayahuasca and Public Health II: Health Status in a Large Sample of Ayahuasca-Ceremony Participants in the Netherlands

Journal of Psychoactive Drugs May 28, 2022 Maja Kohek, Genís Ona, Michiel van Elk et al. 25 citations

Ayahuasca is a plant decoction in traditional Amazonian medicine. Its ritual use has been internationalized, leading to policy challenges that countries should address. This study evaluates the impact of regular ayahuasca ceremony participation on health by assessing the health status of 377 participants in ayahuasca ceremonies in the Netherlands using validated health indicators. A...

Safety issues of psilocybin and LSD as potential rapid acting antidepressants and potential challenges

Expert Opinion on Drug Safety April 15, 2022 Giordano Novak Rossi, Jaime E. C. Hallak, José Carlos Bouso Saiz et al. 24 citations

There were no serious AEs related to psilocybin and LSD administration. Most AEs were expected, manageable, and transient. Nevertheless, safety and tolerability concerns regarding some effects, such as dissociation, paranoia, and confusion, remain. Thus, randomized controlled trials with bigger samples are warranted to confirm their therapeutic effects and further investigate their safety and...

Ayahuasca, a potentially rapid acting antidepressant: focus on safety and tolerability

Expert Opinion on Drug Safety March 18, 2022 Giordano Novak Rossi, Isabella Caroline Da Silva Dias, Glen B. Baker et al. 17 citations

There were no reports of serious AEs, indicating a relative safety of ayahuasca administration in controlled settings. Most common AEs included nausea, vomiting, headaches, and transient increases in cardiovascular measurements. Ayahuasca research is still in its infancy, especially concerning the absence of large and robust clinical trials to verify its antidepressant effects. Dose...

DOI: 10.1080/14740338.2022.2054988 (opens in new tab) Ayahuasca Tolerability Clinical trial Adverse effect +11

Effects of ayahuasca on the endocannabinoid system of healthy volunteers and in volunteers with social anxiety disorder: Results from two pilot, proof‐of‐concept, randomized, placebo‐controlled trials

Human Psychopharmacology: Clinical and Experimental February 2, 2022 Rafael G. Dos Santos, Juliana Mendes Rocha, Giordano Novak Rossi et al. 20 citations

Abstract Objective To assess endocannabinoid (anandamide, AEA; 2‐arachidonoylglycerol, 2‐AG) plasma levels in healthy volunteers and in volunteers with social anxiety disorder (SAD) after a single oral dose of ayahuasca or placebo. Methods Post hoc analysis of endocannabinoid plasma levels (baseline, 90 and 240 min after drug intake) from two parallel‐group, randomized, placebo‐controlled...

DOI: 10.1002/hup.2834 (opens in new tab) Ayahuasca Anxiety Placebo Endocannabinoid system +4

Effects of Ayahuasca on Personality: Results of Two Randomized, Placebo-Controlled Trials in Healthy Volunteers

Frontiers in Psychiatry August 6, 2021 Juliana Mendes Rocha, Giordano Novak Rossi, Flávia de Lima Osório et al. 37 citations

Rationale: Previous studies with the serotonergic hallucinogens LSD and psilocybin showed that these drugs induced changes in personality traits, such as increases in Openness. However, results are inconsistent, and the effects of ayahuasca on personality were never investigated in a controlled trial. Objectives: To assess the effects of ayahuasca on personality in two randomized,...

Ayahuasca Improves Self-perception of Speech Performance in Subjects With Social Anxiety Disorder

Journal of Clinical Psychopharmacology June 23, 2021 Rafael G. Dos Santos, Flávia de Lima Osório, Juliana Mendes Rocha et al. 85 citations

Abstract Background Ayahuasca is a classic hallucinogen with anxiolytic and antidepressive properties. Anecdotal evidence also suggests that it improves performance (eg, singing, speech). This controlled trial assessed the effects of ayahuasca on speech performance and anxiety in individuals with social anxiety disorder. Methods Seventeen volunteers with social anxiety disorder participated in...

DOI: 10.1097/jcp.0000000000001428 (opens in new tab) Ayahuasca Social anxiety Perception Audiology +3

Cross-Sectional Associations Between Lifetime Use of Psychedelic Drugs and Psychometric Measures During the COVID-19 Confinement: A Transcultural Study

Frontiers in Psychiatry June 16, 2021 Dóra Révész, Genís Ona, Giordano Novak Rossi et al. 42 citations

Background: One of the main public health strategies adopted at the beginning of the COVID-19 pandemic consisted of implementing strict lockdowns to stop the transmission of the virus. Despite being an effective measure, the confinement and the associated social isolation create a stressful, potentially lengthy situations that has been proven to have several psychological consequences. Given...

Effects of Ayahuasca on the Recognition of Facial Expressions of Emotions in Naive Healthy Volunteers

Journal of Clinical Psychopharmacology April 13, 2021 Juliana Mendes Rocha, Giordano Novak Rossi, Flávia de Lima Osório et al. 46 citations

Abstract Background The recognition of emotions in facial expressions (REFE) is a core aspect of social cognition. Previous studies with the serotonergic hallucinogens lysergic acid diethylamide and psilocybin showed that these drugs reduced the recognition of negative (fear) faces in healthy volunteers. This trial assessed the acute and prolonged effects of a single dose of ayahuasca on the...

Hallucinogenic/psychedelic 5HT2A receptor agonists as rapid antidepressant therapeutics: Evidence and mechanisms of action

Journal of Psychopharmacology March 19, 2021 Rafael G. Dos Santos, Jaime Ec Hallak, Glen B. Baker et al. 51 citations

Major depressive disorder (MDD) is among the most prevalent mental health disorders worldwide, and it is associated with a reduced quality of life and enormous costs to health care systems. Available drug treatments show low-to-moderate response in most patients, with almost a third of patients being non-responders (treatment-resistant). Furthermore, most currently available medications need...

The Use of Classic Hallucinogens/Psychedelics in a Therapeutic Context: Healthcare Policy Opportunities and Challenges

Risk Management and Healthcare Policy March 1, 2021 Rafael G. Dos Santos, José Carlos Bouso, Juliana Mendes Rocha et al. 58 citations

Psychedelics or serotonergic hallucinogens are a group of substances that share the agonism of serotonergic 5-HT2A receptors as their main mechanism of action. Its main effects include changes in perception, cognitive process, and mood. Despite being used for centuries by different cultures in ritual contexts, these substances have currently aroused the interest of science and industry for...

Rapid and sustained decreases in suicidality following a single dose of ayahuasca among individuals with recurrent major depressive disorder: results from an open-label trial.

Psychopharmacology February 1, 2021 Richard J. Zeifman, Nikhita Singhal, Rafael G. Dos Santos et al. 79 citations

Suicidality is a major public health concern with limited treatment options. Accordingly, there is a need for innovative interventions for suicidality. Preliminary evidence indicates that treatment with the psychedelic ayahuasca may lead to decreases in depressive symptoms among individuals with major depressive disorder (MDD). However, there remains limited understanding of whether ayahuasca...

Psychedelic Medicines in Major Depression: Progress and Future Challenges.

Advances in experimental medicine and biology 2021 José Carlos Bouso, Genís Ona, Rafael G. Dos Santos et al. 6 citations

The volume of research on the therapeutic use of psychedelic drugs has been increasing during the last decades. Partly because of the need of innovative treatments in psychiatry, several studies have assessed the safety and efficacy of drugs like psilocybin or ayahuasca for a wide range of mental disorders, including major depression. The first section of this chapter will offer an introduction...

Neuropharmacological Effects of the Main Phytocannabinoids: A Narrative Review.

Advances in experimental medicine and biology 2021 Rafael G. Dos Santos, Jaime E. C. Hallak, José Alexandre S. Crippa

Cannabis can synthetize more than 400 compounds, including terpenes, flavonoids, and more than 100 phytocannabinoids. The main phytocannabinoids are Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabis-based products are used as medicines in several countries. In this text, we present an overview of the main neurochemical mechanisms of action of the phytocannabinoids, especially THC...

DOI: 10.1007/978-3-030-57369-0_3 (opens in new tab) Full text (opens in new tab) Endocannabinoids Mechanisms of action Neuropharmacology Phytocannabinoids

Risk assessment of ayahuasca use in a religious context: self-reported risk factors and adverse effects

Brazilian Journal of Psychiatry October 30, 2020 Ícaro Durante, Rafael G. Dos Santos, José Carlos Bouso et al. 49 citations

A minority of participants reported being very negatively affected by persistent adverse effects. Psychiatric medication use while participating in ayahuasca rituals was not associated with increased adverse effects. For the most part, the institution's practices seem sufficient to prevent exacerbated reactions. Future studies may focus on negatively affected users.

Polypharmacology or “Pharmacological Promiscuity” In Psychedelic Research: What Are We Missing?

ACS Chemical Neuroscience October 6, 2020 Genís Ona, Rafael G. Dos Santos, Jaime E. C. Hallak et al. 12 citations

Research with psychedelic drugs has mainly focused on isolated compounds. However, this approach is challenged by the "polypharmacology" paradigm. In this Viewpoint, we suggest that we may be missing something if we do not use the whole product in the case of ayahuasca or Psilocybe mushrooms. After describing how research on psychedelic drugs can be effectively combined with the...

Stability Evaluation of DMT and Harmala Alkaloids in Ayahuasca Tea Samples

Molecules April 29, 2020 Gabriela de Oliveira Silveira, Rafael G. Dos Santos, Felipe Rebello Lourenço et al. 36 citations

Ayahuasca tea is a hallucinogenic beverage used for religious purposes in Brazil and many other countries that has therapeutic potential in the treatment of some mental health disorders. In the context of psychedelic research, quantification of the tea’s main alkaloids prior to its administration in animal or human studies is essential. For this reason, this study aims to provide information...

DOI: 10.3390/molecules25092072 (opens in new tab) Ayahuasca Harmine Harmaline Peganum harmala +6

An analytical study of iboga alkaloids contained in Tabernanthe iboga-derived products offered by ibogaine treatment providers

Archives of Clinical Psychiatry (São Paulo) April 1, 2020 José Carlos Bouso, I. Fornís, Mireia Ventura et al. 15 citations

Background: Therapeutic properties of ibogaine in the treatment of addiction are attracting both clinicians and patients to its use. Since ibogaine is not an authorized medicine, the quality of these products is not always known, increasing the probability of adverse reactions. Objective: This study collects different types of iboga-derived samples from treatment providers, vendors and online...