Cannabidiol, a Cannabis sativa constituent, as an anxiolytic drug

Alexandre Rafael de Mello Schier, Natalia Pinho de Oliveira Ribeiro, Adriana Cardoso de Oliveira e Silva, Jaime Eduardo Cecilio Hallak, José Alexandre S. Crippa, Antonio E. Nardi, Antonio Waldo Zuardi

Revista Brasileira de Psiquiatria, 2012, 34 (Supl1), S104-S117

1516-4446 – ©2012 Elsevier Editora Ltda. All rights reserved.

 

Abstract

Objectives : To review and describe studies of the non-psychotomimetic constituent of Cannabis sativa, cannabidiol (CBD), as an anxiolytic drug and discuss its possible mechanisms of action.

Method : The articles selected for the review were identified through searches in English, Portuguese, and Spanish in the electronic databases ISI Web of Knowledge, SciELO, PubMed, and PsycINFO, combining the search terms “cannabidiol and anxiolytic”, “cannabidiol and anxiolyticlike”, and “cannabidiol and anxiety”. The reference lists of the publications included, review articles, and book chapters were handsearched for additional references. Experimental animal and human studies were included, with no time restraints.

Results : Studies using animal models of anxiety and involving healthy volunteers clearly suggest an anxiolytic-like effect of CBD. Moreover, CBD was shown to reduce anxiety in patients with social anxiety disorder.

Conclusion : Future clinical trials involving patients with different anxiety disorders are warranted, especially of panic disorder, obsessive-compulsive disorder, social anxiety disorder, and post-traumatic stress disorders. The adequate therapeutic window of CBD and the precise mechanisms involved in its anxiolytic action remain to be determined.

DESCRIPTORS : Cannabidiol; Cannabis sativa; Anxiolytics; Anxiety disorders.

 

Introduction

Cannabis sativa is the most used drug of abuse worldwide and around 20% of youth use it heavily and regularly around the globe.(1) The main psychoactive component of the plant is Δ9-tetrahydro-cannabinol (Δ9-THC), one of the substances responsible for the psychoactive effects of Cannabis.(2‑4) Cannabidiol (CBD) is another abundant compound in Cannabis sativa, constituting around 40% of the plant’s active substances.(5) The pharmacological effects of CBD are different and often opposite to those of Δ9-THC.(6) The number of publications on CBD has increased remarkably over the last years and support the view that CBD has a vast array of possible therapeutic effects. Among these possibilities, the anxiolytic and antipsychotic properties of CBD stand out.(7‑10) CBD’s anxiolytic effects are apparently similar to those of approved drugs to treat anxiety,(11) although its effective doses have not been clearly established and the mechanisms underlying these effects are not fully understood. The low affinity of CBD for cannabinoid neuroreceptors(12,13) and its agonist properties at 5-HT1A receptors(14,15) have been repeatedly demonstrated. Most studies on CBD have been conducted with rodents, but studies with human samples have also provided promising results.(16,17) Therefore, the aim of this paper is to review the scientific literature on the anxiolytic properties of CBD in animal and in humans.

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