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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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Detoxification from methadone using low, repeated, and increasing doses of ibogaine: A case report

Journal of Psychedelic Studies April 1, 2017 Clare Wilkins, Rafael G. Dos Santos, Jordi Solà et al. 15 citations

Ibogaine is a natural alkaloid that has been used in the last decades as an adjuvant for the treatment of opiate withdrawal. Despite the beneficial results suggested by animal studies and case series, there is a lack of clinical trials to assess the safety and efficacy of ibogaine. Moreover, the majority of reports described cases of heroin-dependent individuals, with and without concomitant...

Anxiety, panic, and hopelessness during and after ritual ayahuasca intake in a woman with generalized anxiety disorder: A case report

Journal of Psychedelic Studies April 1, 2017 Rafael G. Dos Santos, Flávia de Lima Osório, José Alexandre S. Crippa et al. 7 citations

Ayahuasca is a dimethyltryptamine- and β-carboline-rich hallucinogenic beverage traditionally used by indigenous groups of Northwest Amazonian for ritual and therapeutic purposes. Animal and human studies suggest that ayahuasca has antidepressant and anxiolytic potentials and has a good safety profile. However, anxiety-like reactions may also occur after ayahuasca intake, although they are...

Ayahuasca, dimethyltryptamine, and psychosis: a systematic review of human studies

Therapeutic Advances in Psychopharmacology February 23, 2017 Rafael G. Dos Santos, José Carlos Bouso, Jaime E. C. Hallak 167 citations

Ayahuasca is a hallucinogen brew traditionally used for ritual and therapeutic purposes in Northwestern Amazon. It is rich in the tryptamine hallucinogens dimethyltryptamine (DMT), which acts as a serotonin 5-HT 2A agonist. This mechanism of action is similar to other compounds such as lysergic acid diethylamide (LSD) and psilocybin. The controlled use of LSD and psilocybin in experimental...

A randomized placebo-controlled trial on the antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression

bioRxiv (Cold Spring Harbor Laboratory) January 27, 2017 Fernanda Palhano-Fontes, Dayanna Barreto, Heloisa Onias et al. 22 citations preprint

Abstract Recent open label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression. In order to further 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...

Effects of the Naturalβ-Carboline Alkaloid Harmine, a Main Constituent of Ayahuasca, in Memory and in the Hippocampus: A Systematic Literature Review of Preclinical Studies

Journal of Psychoactive Drugs December 5, 2016 Rafael G. Dos Santos, Jaime E. C. Hallak 64 citations

Harmine is a natural β-carboline alkaloid found in several botanical species, such as the Banisteriopsis caapi vine used in the preparation of the hallucinogenic beverage ayahuasca and the seeds of Syrian rue (Peganum harmala). Preclinical studies suggest that harmine may have neuroprotective and cognitive-enhancing effects, and retrospective/observational investigations of the mental health of...

Effects of Ayahuasca and its Alkaloids on Drug Dependence: A Systematic Literature Review of Quantitative Studies in Animals and Humans

Journal of Psychoactive Drugs May 26, 2016 Amanda Amorin Nunes, Rafael G. Dos Santos, Flávia de Lima Osório et al. 92 citations

Recently, the anti-addictive potential of ayahuasca, a dimethyltryptamine(DMT)- and β-carboline-rich hallucinogenic beverage traditionally used by indigenous groups of the Northwest Amazon and currently by syncretic churches worldwide, has received increased attention. To better evaluate this topic, we performed a systematic literature review using the PubMed database to find quantitative...

Antidepressive, anxiolytic, and antiaddictive effects of ayahuasca, psilocybin and lysergic acid diethylamide (LSD): a systematic review of clinical trials published in the last 25 years

Therapeutic Advances in Psychopharmacology March 18, 2016 Rafael G. Dos Santos, Flávia de Lima Osório, José Alexandre S. Crippa et al. 306 citations

To date, pharmacological treatments for mood and anxiety disorders and for drug dependence show limited efficacy, leaving a large number of patients suffering severe and persistent symptoms. Preliminary studies in animals and humans suggest that ayahuasca, psilocybin and lysergic acid diethylamide (LSD) may have antidepressive, anxiolytic, and antiaddictive properties. Thus, we conducted a...

Antidepressive and anxiolytic effects of ayahuasca: a systematic literature review of animal and human studies

Brazilian Journal of Psychiatry March 1, 2016 Rafael G. Dos Santos, Flávia de Lima Osório, José Alexandre S. Crippa et al. 158 citations

Considering the need for new drugs that produce fewer adverse effects and are more effective in reducing anxiety and depression symptomatology, the described effects of ayahuasca and its alkaloids should be further investigated.

Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression

Journal of Clinical Psychopharmacology December 11, 2015 Rafael Faria Sanches, Flávia de Lima Osório, Rafael G. Dos Santos et al. 468 citations

Ayahuasca is an Amazonian botanical hallucinogenic brew which contains dimethyltryptamine, a 5-HT2A receptor agonist, and harmine, a monoamine-oxidase A inhibitor. Our group recently reported that ayahuasca administration was associated with fast-acting antidepressive effects in 6 depressive patients. The objective of the present work was to assess the antidepressive potentials of ayahuasca in...

Effects of nitric oxide-related compounds in the acute ketamine animal model of schizophrenia

BMC Neuroscience March 5, 2015 Ludmyla Kandratavicius, Priscila Alves Balista, Daniele C. Wolf et al. 40 citations

BACKGROUND: Better treatments for schizophrenia are urgently needed. The therapeutic use of the nitric oxide (NO)-donor sodium nitroprusside (SNP) in patients with schizophrenia has shown promising results. The role of NO in schizophrenia is still unclear, and NO modulation is unexplored in ketamine (KET) animal models to date. In the present study, we compared the behavioral effects of pre-...

Ayahuasca Alters Structural Parameters of the Rat Aorta

Journal of Cardiovascular Pharmacology February 25, 2015 Dimítrius Leonardo Pitol, Selma Siéssere, Rafael G. Dos Santos et al. 13 citations

Ayahuasca is a hallucinogenic brew traditionally used by Northwestern Amazonian indigenous groups for therapeutic purposes. It is prepared by the decoction of Banisteriopsis caapi with the leaves of Psychotria viridis. Banisteriopsis caapi contains β-carbolines that are inhibitors of monoamine oxidase and P. viris is rich in dimethyltryptamine, a 5-HT(1A/2A/2C) agonist. Acute ayahuasca...

Long-term use of psychedelic drugs is associated with differences in brain structure and personality in humans

European Neuropsychopharmacology January 16, 2015 José Carlos Bouso, Fernanda Palhano-Fontes, Antoni Rodrı́guez-fornells et al. 221 citations

Psychedelic agents have a long history of use by humans for their capacity to induce profound modifications in perception, emotion and cognitive processes. Despite increasing knowledge of the neural mechanisms involved in the acute effects of these drugs, the impact of sustained psychedelic use on the human brain remains largely unknown. Molecular pharmacology studies have shown that...

Effects of cannabinoid drugs on the deficit of prepulse inhibition of startle in an animal model of schizophrenia: the SHR strain

Frontiers in Pharmacology 2014 Raquel Levin, Fernanda Fiel Peres, Valéria de Almeida et al. 73 citations

Clinical and neurobiological findings suggest that the cannabinoids and the endocannabinoid system may be implicated in the pathophysiology and treatment of schizophrenia. We described that the spontaneously hypertensive rats (SHR) strain presents a schizophrenia behavioral phenotype that is specifically attenuated by antipsychotic drugs, and potentiated by proschizophrenia manipulations. Based...

Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion

Human Brain Mapping September 16, 2011 Dráulio Barros de Araújo, Sidarta Ribeiro, Guillermo Cecchi et al. 241 citations

Abstract The hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors, has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual changes induced by Ayahuasca, the most remarkable are vivid “seeings.” During such seeings, users report potent imagery. Using functional magnetic resonance imaging during a closed‐eyes...

The interplay of cannabinoid and NMDA glutamate receptor systems in humans: preliminary evidence of interactive effects of cannabidiol and ketamine in healthy human subjects.

Progress in neuro-psychopharmacology & biological psychiatry January 15, 2011 Jaime E C Hallak, Serdar M Dursun, Daniel C Bosi et al.

Interactions between glutamatergic and endocannabinoid systems may contribute to schizophrenia, dissociative states, and other psychiatric conditions. Cannabidiol (CBD), a cannabinoid-1/2 (CB1/2) receptor weak partial agonist or antagonist, may play a role in the treatment of schizophrenia. This study tested the hypothesis that CBD would attenuate the behavioral effects of the NMDA receptor...

Performance of schizophrenic patients in the Stroop Color Word Test and electrodermal responsiveness after acute administration of cannabidiol (CBD)

Brazilian Journal of Psychiatry March 1, 2010 Jaime E. C. Hallak, João Paulo Machado‐de‐Sousa, José Alexandre S. Crippa et al. 122 citations

OBJECTIVE: The last decade has seen increasing evidence of dysfunctions in the endogenous cannabinoid system in schizophrenia and of its relationship with the typical cognitive impairment of the disorder. Studies in animal models, healthy volunteers, and psychotic patients clearly suggest an antipsychotic-like effect of cannabidiol. This study investigated the effects of cannabidiol on...

Glutamate and the Neural Basis of the Subjective Effects of Ketamine

Archives of General Psychiatry February 1, 2008 J.f.w. Deakin, Jane Lees, Shane Mckie et al. 315 citations

CONTEXT: Ketamine evokes psychosislike symptoms, and its primary action is to impair N-methyl-D-aspartate glutamate receptor neurotransmission, but it also induces secondary increases in glutamate release. OBJECTIVES: To identify the sites of action of ketamine in inducing symptoms and to determine the role of increased glutamate release using the glutamate release inhibitor lamotrigine....

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug

Brazilian Journal of Medical and Biological Research April 1, 2006 Antônio Waldo Zuardi, José A. Crippa, Jaime E. C. Hallak et al. 411 citations

A high dose of delta9-tetrahydrocannabinol, the main Cannabis sativa (cannabis) component, induces anxiety and psychotic-like symptoms in healthy volunteers. These effects of delta9-tetrahydrocannabinol are significantly reduced by cannabidiol (CBD), a cannabis constituent which is devoid of the typical effects of the plant. This observation led us to suspect that CBD could have anxiolytic...

Acute Psychological Adverse Reactions in First-Time Ritual Ayahuasca Users: A Prospective Case Series.

Journal of Clinical Psychopharmacology María Gómez-sousa, Daniel Jiménez‐garrido, Genís Ona et al. 24 citations

In recent decades, ritualistic use of ayahuasca has spread throughout the world. Retrospective studies have suggested a good psychological safety profile, but prospective studies involving ceremony ayahuasca-naive participants are lacking. We conducted the study using a subsample from a previous study, for which first-time ceremony ayahuasca participants were recruited. The subsample consisted...