Experimental and Clinical Psychopharmacology
November 4, 2021
Tânia Cristina Libânio, R. Eufrásio, Suzy S Niigaki et al.
6 citations
The interest in psychedelic substances as potential treatments for psychiatric disorders is increasing. The β-carboline harmine, an Ayahuasca component, presents hallucinogenic and antidepressant effects. Although Ayuahuasca-and consequently harmine-is usually consumed in rituals, the role of social contexts in the behavioral effects of harmine has not been investigated yet. In this sense,...
Frontiers in Immunology
September 21, 2018
José A. Crippa, Francisco Silveira Guimarães, Alline Cristina Campos et al.
312 citations
Background: Among the many cannabinoids in the cannabis plant, cannabidiol (CBD) is a compound that does not produce the typical subjective effects of marijuana. Objectives: The aim of the present review is to describe the main advances in the development of the experimental and clinical use of cannabidiol CBD in neuropsychiatry. Methods: A non-systematic search was performed for studies...
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...
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...
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...
Psychological Medicine
October 1, 2012
Zerrin Atakan, Sagnik Bhattacharyya, Paul Allen et al.
54 citations
BACKGROUND: Cannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms. Method In a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were...
Archives of General Psychiatry
January 2012
Sagnik Bhattacharyya, José Alexandre S. Crippa, Paul Allen et al.
The aberrant processing of salience is thought to be a fundamental factor underlying psychosis. Cannabis can induce acute psychotic symptoms, and its chronic use may increase the risk of schizophrenia. We investigated whether its psychotic effects are mediated through an influence on attentional salience processing. To examine the effects of Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol...
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...
The International Journal of Neuropsychopharmacology
September 24, 2009
Paolo Fusar‐poli, Paul Allen, Sagnik Bhattacharyya et al.
165 citations
Cannabis sativa, the most widely used illicit drug, has profound effects on levels of anxiety in animals and humans. Although recent studies have helped provide a better understanding of the neurofunctional correlates of these effects, indicating the involvement of the amygdala and cingulate cortex, their reciprocal influence is still mostly unknown. In this study dynamic causal modelling (DCM)...
Archives of General Psychiatry
2009
Paolo Fusar‐poli, José A. Crippa, Sagnik Bhattacharyya et al.
461 citations
CONTEXT: Cannabis use can both increase and reduce anxiety in humans. The neurophysiological substrates of these effects are unknown. OBJECTIVE: To investigate the effects of 2 main psychoactive constituents of Cannabis sativa (Delta9-tetrahydrocannabinol [Delta9-THC] and cannabidiol [CBD]) on regional brain function during emotional processing. DESIGN: Subjects were studied on 3 separate...
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...