The push to legalize cannabis ignores what for many people is a crucial issue: cannabis is dangerous and addicts its users. Just like you’d likely have some issues if someone suggested that we make cocaine available to any adult with $100 to spare, opening up trade to an addictive drug like cannabis which is not free from risk is a questionable proposal.
Continuing our series of the Best Arguments for and Against Cannabis, we’re taking a look at the argument that cannabis is too dangerous and addictive to make legal.
Summary: Should We Ban Cannabis Because It’s Dangerous and Addictive?
Yes…
- Smoking cannabis causes lung cancer, and consuming it any way increases your risk of mental health issues and addiction.
- Legalizing cannabis encourages more people to use it, and therefore increases the risk of these outcomes.
- Cannabis advocates often make comparisons with alcohol, but alcohol would never be legalized if it was invented today.
No…
- The discussion around legalization is not around the risks of use, but whether punishment is just.
- Prohibition doesn’t work, as with alcohol, it just makes products more dangerous and offers less protection for consumers.
- The risks of cannabis are real, but this can be addressed with education and robust product standards.
The Risks of Cannabis Use
The basic point here is something you’ve likely heard many times before. Despite the claims of users and advocates, cannabis use does pose a risk to users and a substantial proportion end up addicted to it.
People could make many specific points here, but the most important ones are:
- Respiratory health risks: Most people consume cannabis by smoking it, so it shouldn’t be a big surprise that there are risks to your lungs and respiratory health. A systematic review of 48 peer-reviewed studies on this point concluded that “inhalational” cannabis poses a risk of lung cancer (an increase of between 2 to 4 times), chronic obstructive pulmonary disease, bullous emphysema and pneumothroax. People who inhale cannabis are also more likely to report wheezing, shortness of breath, coughing and other respiratory symptoms.
- Mental health risks: While the links between cannabis use and mental health conditions tend to be hard to prove, people can make a strong case here. One review of the evidence points out the link between cannabis use disorder and schizophrenia. Cannabis use is associated with two to four times higher risk of developing psychosis in healthy people. Evidence for associations with depression and anxiety is mixed. A multi-center case control study in Europe and Brazil found that cannabis use was associated with 3.2-times higher risks of psychotic disorder. Additionally, removing this risk would prevent about one in eight cases of first-episode psychosis.
- Addiction: Cannabis is addictive. Estimates of how common it is vary, with older (DSM-IV) criteria suggesting it’s about 9% of people who try it and newer, broader criteria (DSM-V) for Cannabis Use Disorder (CUD) suggesting it’s closer to 22%. Likewise, cannabis users experience withdrawal when they stop. Most people will point out that cannabis isn’t as addictive as other drugs, but it is certainly addictive.
Again, this is not an exhaustive list, but these three points are the most well-supported and widely-cited.
With These Risks, Legalizing Cannabis Cannot Be Justified
The argument from this point onwards is pretty straightforward. People are becoming addicted to cannabis, and in turn, continue to expose themselves to the risks of mental health issues, damage to their respiratory system (even lung cancer) and more. This is all the more troubling because of the difficulty in overcoming addiction.
Cannabis advocates will be quick to argue that alcohol is also dangerous to users and addictive, but it is completely legal. But if alcohol was invented today, would it really be something we should make legal? Just because we have historically made mistakes with other substances doesn’t mean we should make it with another one.
The decision to make something legal is saying that this is OK to do and (roughly) acceptable to society. It is, on some level, encouraging the use of the substance, and this cannot be acceptable in the case of cannabis.
Counterpoint: Things Don’t Need to Be Risk-Free to Not Deserve Punishment
Cannabis certainly has risks, and like many other substances, it is addictive. In many ways, it is not something you should encourage people to do. It’s also true that alcohol and cigarettes would not be condoned if they were a new invention.
But this all misses the key point: people are being punished, having their lives turned upside down, over the use of cannabis.
The question isn’t whether cannabis is a good or a bad thing, the question is whether or not it’s right to impose criminal sanctions on its use. Most people can surely agree that if somebody is drinking a couple of glasses of wine with dinner in their free time and not driving afterwards, there is no justifiable reason that this person should be thrown in jail, lose their job or have any serious consequences beyond the possible health risks.
And the issue is very much the same with cannabis. We don’t need to say it’s a great thing that everybody should do, we just need to acknowledge that this is not justification for a punishment from the state.
Additionally, there is a crucial point in that people still use cannabis now. So making the plant illegal has not protected anybody from these risks. In fact, where cannabis is not legal, people make their purchases from street-corner dealers who have no reason to be concerned about purity and have no legal mechanism to prevent under-age purchases.
Legalizing enables society to take control of something that is potentially dangerous. We can institute age restrictions that simply don’t exist on the black market. We can ensure that the cannabis people are using is as safe as possible. Prohibition didn’t stop people drinking, but it certainly increased the number of people going blind from drinking methanol.
Banning based on the existence of risk does not protect anybody; it just increases those exact same risks.
Our Take: Legalize and Educate
Just like with alcohol, in our view, the best solution is to allow adults to make their own choices on cannabis but educate the public about the risks it poses. The risks of cannabis aren’t a myth, even if they’re sometimes overstated, but that doesn’t mean that prohibition is an effective solution. Why legalize it despite the risks? Because banning it doesn’t remove the risks, it just removes the guardrails we would have under a legal system.
References
Respiratory Effects
Martinasek, M. P., McGrogan, J. B., & Maysonet, A. (2016). A Systematic Review of the Respiratory Effects of Inhalational Marijuana. Respiratory Care, 61(11), 1543–1551. https://doi.org/10.4187/respcare.04846
About the source:
- Peer reviewed? Yes, published in Respiratory Care.
- Methodology: A systematic review of peer-reviewed articles addressing the respiratory effects of inhaled cannabis, not including commentaries/editorials, non-English language articles, animal studies and systematic reviews.
- Sample size: 48 articles.
- Main results: There is a risk of lung cancer from inhalational cannabis, and associations with spontaneous pneumothorax, bullous emphysema and COPD. Cannabis smokers also report respiratory symptoms such as wheezing, shortness of breath and coughing.
- Other notes: The title implies any inhaled cannabis was included, but the full text suggests that this really means smoked cannabis. Many of the studies included didn’t control for participants’ cigarette smoking, which makes it hard to be certain the effects were due to cannabis and not tobacco.
Mental Health
Di Forti, M., Quattrone, D., Freeman, T. P., Tripoli, G., Gayer-Anderson, C., Quigley, H., Rodriguez, V., Jongsma, H. E., Ferraro, L., La Cascia, C., La Barbera, D., Tarricone, I., Berardi, D., Szöke, A., Arango, C., Tortelli, A., Velthorst, E., Bernardo, M., Del-Ben, C. M., . . . van der Ven, E. (2019). The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. The Lancet Psychiatry, 6(5), 427–436. https://doi.org/10.1016/s2215-0366(19)30048-3
About the source:
- Peer reviewed? Yes, published in The Lancet Psychiatry.
- Methodology: The researchers recruited adult participants with first-episode across Europe and Brazil, asking about their cannabis use and using existing data to determine whether they used low potency (<10% THC) or high potency (>10% THC) cannabis. The goal was to assess how cannabis use and different patterns of use affect the chance of developing psychotic disorder.
- Sample size: 2,138 participants, including 901 patients and 1,237 controls from local populations.
- Main results: Daily cannabis use was associated with a 3.2-fold increase in risk of psychotic disorder, compared with never users of cannabis. When it was daily use of high-potency cannabis, risk increased 4.8-fold. The researchers calculated that 12.2% of cases of first-episode psychosis would be prevented if high-potency cannabis was not available.
- Other notes: The study assumed that cannabis caused the psychotic disorders observed, rather than establishing it. However, this is consistent with existing research. The authors weren’t able to investigate the impact of CBD on the results, owing to limited data for most sites studied.
Urits, I., Gress, K., Charipova, K., Li, N., Berger, A. A., Cornett, E. M., Hasoon, J., Kassem, H., Kaye, A. D., & Viswanath, O. (2020). Cannabis Use and its Association with Psychological Disorders. Psychopharmacology Bulletin, 50(2), 56–67. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7255842/
About the source:
- Peer reviewed? Yes, published in Psychopharmacology Bulletin.
- Methodology: Narrative review of the recent evidence on cannabis use and psychological disorders.
- Sample size: Excluding those referenced in the introduction, the authors cited 17 peer reviewed papers.
- Main results: One in four patients with schizophrenia are diagnosed with a cannabis use disorder, and cannabis use is associated with a 2 to 4 times greater risk of developing psychosis. Evidence on cannabis use, anxiety and depression has mixed results.
- Other notes: The authors didn’t review the studies in a systematic way. This means it’s possible that they made biased choices on what to include.
Addiction
Gorelick, D. A., Levin, K. H., Copersino, M. L., Heishman, S. J., Liu, F., Boggs, D. L., & Kelly, D. L. (2012). Diagnostic criteria for cannabis withdrawal syndrome. Drug and Alcohol Dependence, 123(1-3), 141–147. https://doi.org/10.1016/j.drugalcdep.2011.11.007
About the source:
- Peer reviewed? Yes, published in Drug and Alcohol Dependence.
- Methodology: Researchers looked at the “most difficult” (unassisted) quit attempt of people who’d smoked cannabis in their lives, to evaluate the diagnostic criteria for cannabis withdrawal from the DSM-V. They included 39 potential withdrawal symptoms in total.
- Sample size: 384 adult, non-treatment seeking lifetime cannabis smokers.
- Main results: 40.9% of participants met the criteria established by the DSM-V for cannabis withdrawal. This was more likely if they had used cannabis for longer or in greater amounts, and people meeting the criteria were abstinent for less time.
- Other notes: The results were based on recall from participants, and some participants reported withdrawal symptoms lasting for up to two years, which is likely a result of other issues.
Leung, J., Chan, G. C. K., Hides, L., & Hall, W. D. (2020). What is the prevalence and risk of cannabis use disorders among people who use cannabis? a systematic review and meta-analysis. Addictive Behaviors, 109, 106479. https://doi.org/10.1016/j.addbeh.2020.106479
About the source:
- Peer reviewed? Yes, published in Addictive Behaviors.
- Methodology: A systematic review and meta-analysis of cross-sectional and longitudinal studies on cannabis use disorders, cannabis abuse and cannabis dependence in users, defined based on DSM or ICD criteria.
- Sample size: 21 studies were included in the analysis.
- Main results: Among people who use cannabis, 22% have cannabis use disorder, 13% meet criteria for cannabis abuse and 13% have cannabis dependence. The risk is greater for young people who use cannabis either daily or weekly.
- Other notes: The studies included in this analysis varied substantially, including different definitions of cannabis addiction and different definitions of what constitutes a “user.” This is likely why the resulting estimates vary so much.
Volkow, N. D., Baler, R. D., Compton, W. M., & Weiss, S. R. B. (2014). Adverse Health Effects of Marijuana Use. New England Journal of Medicine, 370(23), 2219–2227. https://doi.org/10.1056/nejmra1402309
About the source:
- Peer reviewed? Yes, published in the New England Journal of Medicine.
- Methodology: A narrative (non-systematic) review of evidence about the adverse effects of cannabis use.
- Sample size: 74 studies referenced, not including the introduction and conclusion.
- Main results: Around 9% of those who experiment with cannabis will end up addicted, based on DSM-IV criteria. The paper argues that cannabis exposure in adolescence has negative effects on brain development, that cannabis may act as a “gateway drug,” increases the risk of road accidents and increases the risk of cardiovascular and respiratory issues.
- Other notes: The authors didn’t review the studies systematically, so there is a chance of bias. For example, they only briefly mentioned alternative to the gateway hypothesis even though it has a lot of backing.