Marijuana, the flowering part of the cannabis plant, has been used by numerous cultures around the world for thousands of years for both recreational and medicinal use. Yet, following the Controlled Substances Act of 1971, cannabis became federally illegal in the US. Due to its current status, there is limited information available about the pharmacology, pharmacokinetics, and pharmacodynamics of cannabis and how it should be used as a medicine. In fact, in 2019, the best advice a healthcare professional or cannabis expert can provide is the old adage of “start low, go slow” when dosing. We can do better, especially when it comes to mitigating the risk of cannabis dependence.
While much progress has been made over the past several years by cannabis activists to increase access to and research on the plant, political and sociocultural barriers stand in the way of national legalization. One of the reasons policymakers and prohibitionists often cite as a reason to keep cannabis illegal at the federal level is its “addictive” nature. Since there is a lot of misinformation out there on the internet and in social media regarding cannabis, it’s often hard to tell fact from fiction. So, is there any truth to this claim? Is marijuana addictive?
Cannabis Dependence AKA Cannabis Use Disorder AKA Marijuana Use Disorder
Be sure to read our article on Marijuana Use Disorder, which provides even more information.
Let’s start by defining what addiction means. Substances that produce euphoric effects (like opioids) do so by increasing chemicals in the brain (called neurotransmitters), which normally respond to rewards like food or sex. The pairing of a chemical with a rewarding feeling over time increases the propensity to consume that substance; essentially, the body and brain become dependent on that chemical to feel good and trigger emotional and physical “cravings” when that chemical is not available.
And there is evidence that some people do become dependent on cannabis. So, yes, marijuana dependence is real. In fact, cannabis use disorder is included in the guidebook used by physicians and mental health professionals, called The Diagnostic and Statistical Manual of Mental Disorders, or the DSM.
According to the most recent edition of the DSM, which is published by the American Psychiatric Association, cannabis use disorder is “a problematic pattern of cannabis use leading to clinically significant impairment or distress.” To be diagnosed, people must also exhibit behavior related to psychosocial or physical problems or signs of cannabis withdrawal or tolerance within a 12-month period.
A JAMA Psychiatry study based on data from a 2012-2013 national survey of 118,497 participants reported that 2.9% of participants had cannabis use disorder. Another study published in the American Journal of Psychiatry found that the lifetime prevalence of cannabis use disorder was 6.3%. In this study, researchers interviewed 36,309 participants using the latest DSM guidelines for diagnosis.
It is important to note that, while these numbers may be a bit lower than what you have seen on certain web sites and channels describing the negative effects of cannabis, the prevalence of cannabis use disorder has increased concurrently with greater legalization, and possibly due to the shift from use of cannabis flower to more potent concentrates. It is also important to note that withdrawal from cannabis is not equal in severity to discontinuing use of alcohol or opiates.
Genetic Correlates of Cannabis Dependence
Whether one becomes dependent on cannabis is determined by many different factors, including genetics, age, and environment. And researchers have made great progress in identifying some of the genetic determinants of dependence in the past few years.
Using a research approach called a genome-wide association study, or GWAS, scientists can look at genetic variations in a large group of people to determine if certain factors are associated with a behavior or condition of interest—in this case, cannabis dependence. A GWAS study published in JAMA Psychiatry identified single nucleotide polymorphisms (SNPs), common genetic variations, associated with cannabis dependence in a group of nearly 15,000 people. These SNPs also explained the potential relationship between cannabis dependence and depression and schizophrenia.
A GWAS study published in Nature Neuroscience of over 50,000 people identified a single gene, called CHRNA2, associated with cannabis dependence. Previous studies have implicated CHRNA2 in substance abuse, including nicotine dependence. Further research is needed to better understand how this gene could contribute to cannabis dependence but the authors were optimistic that this gene’s protein could represent a novel therapeutic target.
A more recent study shed further light on this issue by exploring how genetics influence cannabis satiety and cravings. Forty-eight cannabis users were genotyped to determine if they had any SNPs in the cannabinoid receptor 1 gene or fatty acid amide hydrolase (FAAH) gene, which has been implicated in cannabis use disorder. Participants were given THC, THC+CBD, or CBD (or a placebo, a non-active substance) and then asked questions about cannabis cravings and tested on attention. Significant differences in behavior were identified in people who had certain SNPs compared to those who did not. This study’s unique approach, which teased out behaviors that could lead to the development of cannabis use disorder rather than evaluating those already diagnosed, provides important insights on how to potentially screen users and prevent the disorder from developing.
While there is currently no therapy approved for cannabis use disorder, the condition can be managed with psychosocial intervention. Cognitive behavioral therapy, which uses a method of cognitive restructuring and pro-social behaviors, can be very effective. Additionally, motivational enhancement therapy uses an empathic, non-confrontational approach to promote behavioral changes.
A recent study found that a cannabis-based therapy called Sativex approved globally (but not in the US) for spasticity associated with multiple sclerosis might also be helpful for people with cannabis use disorder.
While it might seem strange to treat cannabis use disorder with cannabis, the research described above supports this approach, as changes affecting endocannabinoid receptors are clearly involved in this condition. In fact, a Phase 2 trial published in the Lancet Psychiatry also supports this theory. This trial found that administration of a novel FAAH inhibitor reduced cannabis withdrawal and use in a group of 46 men.
“A lot of other drugs have been tested for their ability to reduce cannabis use and withdrawal, but until now none have been consistently shown to work against both withdrawal symptoms and relapse. Furthermore, unlike cannabis or its principal active constituent delta-9 THC, FAAH inhibitors do not appear to have psychoactive or rewarding effects, and are therefore not likely to be abused,” said Deepak Cyril D’Souza, MD, lead author of the study, in a press release.
So, can you get addicted to weed? Is cannabis dependence actually a thing? Yes.
Do we need more research to better understand why and how this happens in certain people? Also, yes.
Luckily, Strain Genie can provide you with information about your genetics and provide recommendations based on your chemical makeup to make more informed choices about your cannabis use.
Get started and order a kit today (you can even use your 23andMe or Ancestry.com data if you’ve already been tested by them!)