Cannabis May Treat Alcohol Abuse Disorder
Many patients report successfully overcoming alcohol addiction through treatment with cannabis.
The endocannabinoid system is involved in regulating many physiological systems, including the reward system in the brain. General studies on the endocannabinoid system and its role in addiction have found that activating the CB1 receptor increases dopamine signaling in certain regions of the brain and many addictive substances have an effect on endocannabinoid signaling.
For example, consuming alcohol causes endocannabinoid levels to increase in certain parts of the brain, and this triggers activation of the cannabinoid receptor CB1. Scientists have wondered if cannabis, or other cannabinoids, can be used to manipulate the reward system and help those with all kinds of addictions, including alcohol use disorder.
A number of pre-clinical studies (i.e., using animals) show that endocannabinoid signaling changes with alcohol consumption. And further, that cannabinoid receptors play a critical role in the rewarding aspects of alcohol consumption and addiction to it. Several animal studies found that the activation of the CB1 receptor increases alcohol consumption in animals predisposed to alcoholism. In addition, molecules that reduce or block the activity of the CB1 receptor suppresse alcohol consumption in animals.
The animal studies suggest that inhibiting the CB1 receptor would be a good therapeutic approach to treating alcoholism. To date, there have been just two human studies on the effects of a CB1 inhibitor on alcoholism, and neither produced any significant effects. Patients in these studies did not see reductions in their want to drink. Further, they did not see reductions in the rate of relapse compared to placebo.
These studies have several limitations, however. Mainly including such a small number of patients, and using such a single, low dose. Perhaps an effect would have been detectable at different doses. The inhibitor from these studies, rimonabant, has since seen withdrawl from the European market. This is because of its adverse psychological effects. Basically, this means we will have to develop other CB1 inhibitors or blockers if this line of research is to continue.
There are other cannabinoids that may be better alternatives for blocking the CB1 receptor, like delta-9-tetrahydrocannabivarin (THCV), a “neutral antagonist” of the CB1 receptor. In addition, cannabidiol (CBD) is thought to counter the psychoactive effects of delta-9-tetrahydrocannabinol (THC), so while it does not block the CB1 receptor, it may work through a different mechanism on the reward center. Specifically, it may help AUD in people also fighting post-traumatic stress disorder.
Doctors initially sought participants in August 2017. However, they had not yet started recruiting participants as of end of 2017. One research study found that CBD was effective at reducing alcohol consumption and reduced relapse in mice. The study authors propose that as a mechanism, CBD interferes with the motivation to consume alcohol. It essentially rewires the reward pathways in the brain.
Since the primary cannabinoid in cannabis is THC, a molecule that activates the CB1 receptor, it seems unlikely that the use of medical marijuana could help treat alcoholism. However, an interesting wrinkle in the research of cannabis use and alcoholism is that some alcoholics are also cannabis users. Further, some chronic cannabis users are heavy drinkers. Many of the studies on the concurrent use of cannabis and alcohol have found that cannabis and alcohol complement each other, so they are often used together to improve the effect of the other. Many studies indicate that they are often substituted for one another. Thereby people may choose to smoke cannabis instead of drink alcohol.
Can cannabis use help an alcoholic to quit drinking?
Overall, the studies indicate that smoking cannabis does not significantly inhibit one’s attempts to quit drinking, nor does it significantly improve them. For example, one study on the impact of cannabis use on the recovery of alcoholics finds that frequent cannabis use does not differ from the group who did not use cannabis in the rate of relapse or return to drinking. Frequent use is usage more than 3 times a month. The researchers hypothesize that the group of regular users may have substituted cannabis use for alcohol use. This is especially true since this pattern functions in small, non-clinical, studies. This finding is encouraging and contrary to the hypothesis that cannabis use would foil attempts to quit drinking.
The endocannabinoid system plays a role in alcohol use disorder, particularly in reinforcing the reward system activation via the CB1 receptor. The current research on using cannabinoids to treat alcoholism has not yet produced any viable therapies. The animal studies indicate that inhibiting CB1 receptors should suppress the desire to drink. However, human studies do not yet corroborate this. Previous human clinical studies had several limitations, and we need further trials. Indeed, at least one clinical trial is likely to begin in 2018. Cannabis frequently substitutes or complements alcohol for recreation. Because of this, some alcoholics may find it helpful to alleviate the symptoms of withdrawal, and to suppress drinking urges.