Antidepressive and anxiolytic effects of ayahuasca : a systematic literature review of animal and human studies, Rafael G. dos Santos et al., 2016

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

Rafael G. dos Santos, Flavia L. Osorio, José Alexandre S. Crippa, Jaime E.C. Hallak

Revista Brasileira de Psiquiatria, 2016, 38, 65–72

doi:10.1590/1516-4446-2015-1701

 

ABSTRACT

Objective : To conduct a systematic literature review of animal and human studies reporting anxiolytic or antidepressive effects of ayahuasca or some of its isolated alkaloids (dimethyltryptamine, harmine, tetrahydroharmine, and harmaline).

Methods : Papers published until 3 April 2015 were retrieved from the PubMed, LILACS and SciELO databases following a comprehensive search strategy and using a predetermined set of criteria for article selection.
Results : Five hundred and fourteen studies were identified, of which 21 met the established criteria. Studies in animals have shown anxiolytic and antidepressive effects of ayahuasca, harmine, and harmaline, and experimental studies in humans and mental health assessments of experienced ayahuasca consumers also suggest that ayahuasca is associated with reductions in anxiety and depressive symptoms. A pilot study reported rapid antidepressive effects of a single ayahuasca dose in six patients with recurrent depression.
Conclusion : 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.

Keywords : Psychedelic agents; dimethyltryptamine; harmine; monoamine oxidase inhibitors; therapeutic use

 

Introduction

Ayahuasca is a Quechua name used to describe a pan-Amazonian botanical hallucinogenic beverage produced by boiling the stems of the liana Banisteriospsis caapi with the leaves of the shrub Psychotria viridis.1,2B. caapi is rich in β-carbolines such as harmine, tetrahydroharmine (THH), and harmaline, while P. viridis contains considerable amounts of the hallucinogenic tryptamine N,N-dimethyl-tryptamine (DMT), a 5-HT1A/2A/2C agonist.1 2 3 45 Pure DMT is not psychoactive after oral administration,6 but liver and gastrointestinal monoamine oxidase A (MAO-A) inhibition by the β-carbolines in ayahuasca – especially by harmine – allows DMT to reach the systemic circulation and the brain, where it activates 5-HT1A/2A/2C receptors in frontal and paralimbic areas.5,7,8

Ayahuasca has been traditionally used by indigenous and mestizo populations of Amazonian countries such as Brazil, Colombia, Peru, and Ecuador for magical-religious and therapeutic purposes.1,2 However, in the last 25 years, ritual and therapeutic use of ayahuasca has spread from small cities in the Amazonian jungle to the urban centers of South America, United Sates, Europe, Asia, and Africa.9

Anecdotal evidence, studies conducted among ayahuasca consumers, and preliminary studies in patients suggest that ayahuasca has broad therapeutic potential, especially for the treatment of substance dependence and anxiety and mood disorders.10 11 12 13 14 15 16 1718 Moreover, pharmacological studies of acute ayahuasca administration to healthy volunteers and mental health assessments of long-term ayahuasca consumers suggest that this compound is relatively safe.4,5,7,1015,19 2021

Thus, this study aimed to conduct a systematic literature review of animal and human studies that investigated anxiolytic and antidepressive effects of ayahuasca or of some of its isolated alkaloids (dimethyltryptamine, harmine, THH, and harmaline).

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