Cannabidiol as an Intervention for Addictive Behaviors : A Systematic Review of the Evidence
Mélissa Prud’homme, Romulus Cata and Didier Jutras-Aswad
Substance Abuse : Research and Treatment, 2015, 9, 33-38.
doi : 10.4137/SART.S25081.
Drug addiction is a chronically relapsing disorder characterized by the compulsive desire to use drugs and a loss of control over consumption. Cannabidiol (CBD), the second most abundant component of cannabis, is thought to modulate various neuronal circuits involved in drug addiction. The goal of this systematic review is to summarize the available preclinical and clinical data on the impact of CBD on addictive behaviors. MEDLINE and PubMed were searched for English and French language articles published before 2015. In all, 14 studies were found, 9 of which were conducted on ani-mals and the remaining 5 on humans. A limited number of preclinical studies suggest that CBD may have therapeutic properties on opioid, cocaine, and psychostimulant addiction, and some preliminary data suggest that it may be beneficial in cannabis and tobacco addiction in humans. Further studies are clearly necessary to fully evaluate the potential of CBD as an intervention for addictive disorders.
Keywords : review, cannabidiol, drug addiction, addictive behaviors, treatment
Drug addiction is a chronically relapsing disorder characterized by the compulsive desire to seek and use drugs with impaired control over substance use despite negative consequences.1 In all, 162–324 million people between the ages of 15 and 64 have used an illicit substance worldwide in 2012, and approximately 183,000 deaths were thought to be drug related.2 In the past decade the advent of new technologies has allowed for a better understanding of the neural mechanisms involved in addictive disorders. The glutamatergic and dopaminergic systems have been found to play an important role in the reinforcing effects of drugs and prolonged risk of relapse.3–5 Moreover, the endocannabinoid system (ECBS) has been shown to influence the acquisition and maintenance of drug-seeking behaviors, through its role in reward and brain plasticity.6,7 Cannabinoid receptors have been studied in addiction-related processes, with special attention paid to cannabinoid type 1 (CB1) receptors. Other ionotropic cannabinoid receptors are also linked to neurophysiological functions in the ECBS, such as transient receptor potential receptors, including transient receptor vanilloid potential 1 (TRVP1), which binds the endogenous cannabinoid anandamide (AEA)5 (Supplementary Table 1 lists the abbreviations).
Among the compounds found to modulate the ECBS, Δ9-tetrahydrocannabinol (THC) has been widely studied since its discovery in the 1960s as the main component of cannabis extract. Its psychosis and anxiety-inducing addictive properties are well known.8,9 In contrast, cannabidiol (CBD), the second most abundant component of cannabis – less studied than THC – has been shown to have anxiolytic, antipsychotic, antidepressant, and neuroprotective properties.10–13 CBD acts on the ECBS as a weak inverse agonist on CB1 receptors, stimulates the TRVP1, and alters the hydrolysis of AEA by inhibiting fatty acid amine hydrolase.14–16 CBD has been shown to be an agonist of 5-HT1a serotoninergic receptors and to regulate stress response and compulsive behaviors.17 Moreover, CBD modulates allosterically μ and δ opioid receptors. The direct impact of CBD on glutamatergic neurotransmission is not known, but its protective effects on glutamate toxicity have been studied.18,19 Altogether, CBD has been associated with many neural circuits involved in the acquisition of addiction and subsequent drug-seeking behaviors, making it an interesting pharmacological candidate to treat substance-use disorders.
In past years, several researchers have studied the effects of CBD on physical and mental health, and a growing number have focused on the effects of CBD on addiction. The main objective of this review is to systematically examine the existing preclinical and clinical evidence on the effects of CBD on addictive behaviors.