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Jaime E. C. Hallak

Universidade de São Paulo, Clinics Hospital of Ribeirão Preto

95 papers in the library · 6,620 citations · publishing 0-2026

Papers

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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...

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...

Effects of ayahuasca on mental health and quality of life in naïve users: A longitudinal and cross-sectional study combination

Scientific Reports March 5, 2020 José Carlos Bouso, Daniel Jiménez‐garrido, María de Lourdes Gómez-sousa et al. 111 citations

Abstract Ayahuasca is a hallucinogenic decoction used as a traditional medicine in several Amazonian regions. The ritualistic use of ayahuasca has spread throughout many countries, making it necessary to study its risks and benefits. Two sub-studies were designed for this investigation. In sub-study 1, a psychiatric interview and a battery of questionnaires were administered to subjects (n =...

The Impact of Ayahuasca on Suicidality: Results From a Randomized Controlled Trial

Frontiers in Pharmacology November 19, 2019 Richard J. Zeifman, Fernanda Palhano-Fontes, Jaime E. C. Hallak et al. 79 citations

Suicide is a major public health problem. Given increasing suicide rates and limitations surrounding current interventions, there is an urgent need for innovative interventions for suicidality. Although ayahuasca has been shown to target mental health concerns associated with suicidality (i.e., depression and hopelessness), research has not yet explored the impact of ayahuasca on suicidality....

Serotonergic hallucinogens/psychedelics could be promising treatments for depressive and anxiety disorders in end-stage cancer

BMC Psychiatry October 28, 2019 Rafael G. Dos Santos, José Carlos Bouso, Jaime E. C. Hallak 17 citations

In a recent issue of the BMC Psychiatry, the evidence of effectiveness of treatments for psychiatric conditions in end-stage cancer patients was reviewed (Johnson, 2018). The review was comprehensive, and included traditional and non-traditional/alternative treatments, including herbal medicines and spirituality. However, evidence showing that classic or serotonergic hallucinogens/psychedelics...

Ayahuasca, an ancient substance with traditional and contemporary use in neuropsychiatry and neuroscience

Epilepsy & Behavior June 7, 2019 Rafael G. Dos Santos, Jaime E. C. Hallak 58 citations

Ayahuasca is a botanical hallucinogenic preparation traditionally used for ritual and therapeutic purposes by native populations of the Northwestern Amazon. In the last decades, ayahuasca use has spread to Europe, the United States, Asia, and Africa, and interest in the possible therapeutic uses of ayahuasca for treating anxiety and mood disorder and substance-use disorders has increased both...

Internet method for the extraction of N,N-dimethyltryptamine from Mimosa hostilis roots: Does it really extract dimethyltryptamine?

Journal of Psychedelic Studies March 1, 2019 Giordano Novak Rossi, Eduardo José Crevelin, Gabriela de Oliveira Silveira et al. 10 citations

Background and aims The psychoactive capacity of the alkaloid N,N-dimethyltryptamine (DMT) has been known for decades, and its presence in beverages used in religious contexts around the world – such as ayahuasca – has attracted growing attention from the scientific community due to its possible anxiolytic and antidepressant effects. Mimosa hostilis, popularly known as jurema preta in Brazil,...

Ayahuasca and Public Health: Health Status, Psychosocial Well-Being, Lifestyle, and Coping Strategies in a Large Sample of Ritual Ayahuasca Users

Journal of Psychoactive Drugs February 7, 2019 Genís Ona, Maja Kohek, Tomàs Massaguer et al. 76 citations

Assessing the health status of ayahuasca users has been challenging due to the limitations involved in randomized clinical trials and psychometric approaches. The main objective of this study is the implementation of an approach based on public health indicators. We developed a self-administered questionnaire that was administered to long-term ayahuasca users around Spain. The questionnaire was...

Serotonergic hallucinogens and recognition of facial emotion expressions: a systematic review of the literature

Therapeutic Advances in Psychopharmacology 2019 Juliana Mendes Rocha, Flávia de Lima Osório, José Alexandre S. Crippa et al. 44 citations

Background: Recognition of emotions in facial expressions (REFE) is a key aspect of social cognition. Anxiety and mood disorders are associated with deficits in REFE, and anxiolytics and antidepressants reverse these deficits. Recent studies have shown that serotonergic hallucinogens (i.e. ayahuasca, dimethyltryptamine, psilocybin, lysergic acid diethylamide [LSD], and mescaline) have...

Acute effects of ayahuasca in a juvenile non-human primate model of depression

Brazilian Journal of Psychiatry November 21, 2018 Flávia S. Da Silva, Erick Allan Dos Santos Silva, Geovan Menezes de Sousa et al. 46 citations

OBJECTIVE: The incidence rate of major depression in adolescents reaches approximately 14%. This disorder is usually recurrent, without remission of symptoms even after pharmacological treatment, and persists throughout adult life. Since the effects of antidepressants take approximately 2 weeks to begin, new pharmacological therapies are under continuous exploration. Recent evidence suggests...

Possible Interactions Between 5-HT2A Receptors and the Endocannabinoid System in Humans

Journal of Clinical Psychopharmacology October 19, 2018 Rafael G. Dos Santos, José Alexandre S. Crippa, Flávia de Lima Osório et al. 9 citations

dos Santos, Rafael Guimarães PhD; Crippa, José Alexandre MD, PhD; Osório, Flávia de Lima PhD; Rocha, Juliana M. BSc; Rossi, Giordano Novak BSc; Marchioni, Camila BSc; Queiroz, Maria Eugênia Costa PhD; Silveira, Gabriela O. BSc; Yonamine, Mauricio PhD; Hallak, Jaime Eduardo Cecilio MD, PhD Author Information

Efficacy, tolerability, and safety of serotonergic psychedelics for the management of mood, anxiety, and substance-use disorders: a systematic review of systematic reviews

Expert Review of Clinical Pharmacology August 13, 2018 Rafael G. Dos Santos, José Carlos Bouso, Miguel Ángel Alcázar‐córcoles et al. 231 citations

Mood, anxiety, and substance-use disorders are among the most prevalent psychiatric disorders in the population. Although several pharmacological treatments are available, they are not effective for a significant proportion of patients and are associated with several adverse reactions. Therefore, new treatments should be explored. Recent studies suggest that serotonergic...

“Ayahuasca turned on my mind’s eye”: Enhanced visual imagery after ayahuasca intake in a man with “blind imagination” (aphantasia)

Journal of Psychedelic Studies July 25, 2018 Rafael G. Dos Santos, Scotty Enyart, José Carlos Bouso et al. 18 citations

Aphantasia ("blind imagination") is a poorly described condition with an uncertain etiology, characterized by reduced or lack of voluntary visual imagery. Preliminary evidence in humans suggests that hallucinogenic or psychedelic drugs that act as agonists of cortical 5-HT2A receptors [lysergic acid diethylamide, psilocybin, and dimethyltryptamine (DMT)] enhance visual imagery. Interview and...

Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial

Psychological Medicine June 15, 2018 Fernanda Palhano-Fontes, Dayanna Barreto, Heloisa Onias et al. 827 citations

Abstract Background Recent open-label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression. Methods To test the antidepressant effects of ayahuasca, we conducted a parallel-arm, double-blind randomized placebo-controlled trial in 29 patients with treatment-resistant depression. Patients received a single dose of either...

Psychedelics and Personality

ACS Chemical Neuroscience June 4, 2018 Marc Aixalà, Rafael G. Dos Santos, Jaime E. C. Hallak et al. 14 citations

In the past decade, an increasing number of clinical trials are reporting evidence that psychedelics or serotonergic hallucinogens (such as lysergic acid diethylamide, psilocybin, and ayahuasca/dimethyltryptamine) could be effective in the treatment of mood, anxiety, and substance use disorders. The mechanisms responsible for these effects are not fully understood but seem to involve changes in...

Ayahuasca: Psychological and Physiologic Effects, Pharmacology and Potential Uses in Addiction and Mental Illness

Current Neuropharmacology March 2, 2018 Jonathan Hamill, Jaime E. C. Hallak, Serdar Dursun et al. 179 citations

Background: Ayahuasca, a traditional Amazonian decoction with psychoactive properties, is made from bark of the Banisteriopsis caapi vine (containing beta-carboline alkaloids) and leaves of the Psychotria viridis bush (supplying the hallucinogen N,N-dimethyltryptamine, DMT). Originally used by indigenous shamans for the purposes of spirit communication, magical experiences, healing, and...

Author Correction: Well-being, problematic alcohol consumption and acute subjective drug effects in past-year ayahuasca users: a large, international, self-selecting online survey

Scientific Reports February 28, 2018 Will Lawn, Jaime E. C. Hallak, José A. Crippa et al. 3 citations

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Serotonergic psychedelics and personality: A systematic review of contemporary research

Neuroscience & Biobehavioral Reviews February 13, 2018 José Carlos Bouso, Rafael G. Dos Santos, Miguel Ángel Alcázar‐córcoles et al. 135 citations

Serotonergic psychedelics act as agonists at cortical 5-HT2A receptors and seem to induce personality changes. We conducted a systematic review of studies assessing the effects of these drugs on personality. Papers published from 1985-2016 were included from PubMed, LILACS, and SciELO databases. Three hundred and sixty-nine studies were identified, and 18 were included. Specific personality...

Long-term effects of ayahuasca in patients with recurrent depression: a 5-year qualitative follow-up

Archives of Clinical Psychiatry (São Paulo) February 1, 2018 Rafael G. Dos Santos, Rafael Faria Sanches, Flávia de Lima Osório et al. 37 citations

Abstract Background Ayahuasca is a botanical hallucinogenic preparation traditionally used by indigenous populations of Northwestern Amazonian countries for ritual and therapeutic purposes. It is rich in β-carboline alkaloids and N,N-dimethyltryptamine (DMT). Preclinical, observational, and experimental studies suggest that ayahuasca and its alkaloids have anxiolytic and antidepressive effects....

Well-being, problematic alcohol consumption and acute subjective drug effects in past-year ayahuasca users: a large, international, self-selecting online survey

Scientific Reports November 3, 2017 Will Lawn, Jaime E. C. Hallak, José Alexandre S. Crippa et al. 78 citations

Abstract Ayahuasca is a natural psychedelic brew, which contains dimethyltryptamine (DMT). Its potential as a psychiatric medicine has recently been demonstrated and its non-medical use around the world appears to be growing. We aimed to investigate well-being and problematic alcohol use in ayahuasca users, and ayahuasca’s subjective effects. An online, self-selecting, global survey examining...

Ayahuasca: what mental health professionals need to know

Archives of Clinical Psychiatry (São Paulo) August 1, 2017 Rafael G. Dos Santos, José Carlos Bouso, Jaime E. C. Hallak 15 citations

Abstract Background Ayahuasca is a psychoactive ethnobotanical concoction that has been used for decades by indigenous groups of the Northwestern Amazon and by syncretic religious organizations for ritual and therapeutic purposes. In the last two decades, it is being used worldwide in evolving practices. Ayahuasca seem to therapeutic effects, but controlled studies are lacking. Moreover, its...

Cannabinoids and Vanilloids in Schizophrenia: Neurophysiological Evidence and Directions for Basic Research

Frontiers in Pharmacology June 21, 2017 Rafael Naime Ruggiero, Matheus Teixeira Rossignoli, Jana Batista de Ross et al. 37 citations

Much of our knowledge of the endocannabinoid system in schizophrenia comes from behavioral measures in rodents, like prepulse inhibition of the acoustic startle and open-field locomotion, which are commonly used along with neurochemical approaches or drug challenge designs. Such methods continue to map fundamental mechanisms of sensorimotor gating, hyperlocomotion, social interaction, and...

Assessing the Psychedelic “After-Glow” in Ayahuasca Users: Post-Acute Neurometabolic and Functional Connectivity Changes Are Associated with Enhanced Mindfulness Capacities

The International Journal of Neuropsychopharmacology May 17, 2017 Frederic Sampedro, Mario de la Fuente Revenga, Marta Valle et al. 205 citations

Background: Ayahuasca is a plant tea containing the psychedelic 5-HT2A agonist N,N-dimethyltryptamine and harmala monoamine-oxidase inhibitors. Acute administration leads to neurophysiological modifications in brain regions of the default mode network, purportedly through a glutamatergic mechanism. Post-acutely, ayahuasca potentiates mindfulness capacities in volunteers and induces rapid and...

Inverted U-Shaped Dose-Response Curve of the Anxiolytic Effect of Cannabidiol during Public Speaking in Real Life

Frontiers in Pharmacology May 11, 2017 Antônio Waldo Zuardi, Natália Pegoraro Rodrigues, Angélica L. Silva et al. 292 citations

The purpose of this study was to investigate whether the anxiolytic effect of cannabidiol (CBD) in humans follows the same pattern of an inverted U-shaped dose-effect curve observed in many animal studies. Sixty healthy subjects of both sexes aged between 18 and 35 years were randomly assigned to five groups that received placebo, clonazepam (1 mg), and CBD (100, 300, and 900 mg). The subjects...

The antiaddictive effects of ibogaine: A systematic literature review of human studies

Journal of Psychedelic Studies April 1, 2017 Rafael G. Dos Santos, José Carlos Bouso, Jaime E. C. Hallak 36 citations

Ibogaine is a naturally occurring hallucinogenic alkaloid with a therapeutic potential for reducing drug craving and withdrawal. To the best of our knowledge, no systematic review was previously performed assessing these effects. Thus, we conducted a systematic literature review of human studies assessing the antiaddictive effects of ibogaine. Papers published up to July 2, 2016 were included...