Should People Use Cannabis? The Pros and Cons of the Ongoing Debate

Written by

Lee Johnson

Lee Johnson is the senior editor at CBD Oracle, and has been covering science, vaping and cannabis for over 10 years. He has a MS in Theoretical Physics from Uppsala...

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Even with more states and countries moving towards legalization of cannabis, it can still be a highly controversial issue. On one side, people say that cannabis consumption has few (if any) serious consequences and it can be a benefit to individuals and local economies, while on the other people contest that there are serious risks, it could lead to further drug use and many other societal issues.

Navigating this web of contradictory opinions and strongly-held views can be difficult, but if you see the cases for both sides laid out clearly, it’s easier to weigh the facts and come to your own conclusion. So here is a run-down of the main arguments from each side of the debate.

The Cannabis Debate

Pro Cannabis

  1. Cannabis is safer than alcohol or tobacco, and those are legal
  2. Using cannabis is a victimless crime
  3. Legalizing cannabis generates money for local governments
  4. Addiction should be treated medically, not punished
  5. Cannabis has many medical uses

Against Cannabis

  1. Smoking cannabis is bad for your lungs
  2. Cannabis leads to mental health issues
  3. Cannabis is a gateway to other drugs
  4. Cannabis is addictive
  5. Cannabis fuels the drug trade
  6. Cannabis makes you dumb

Against: Smoking Cannabis is Bad for Your Lungs

Teen girl smoking weed
Photo/Chris Roussakis

Like smoking basically anything, smoking cannabis damages your lungs. The picture is a little complicated, though, because while cannabis smoke contains many of the same harmful chemicals as cigarette smoke, most of the possible links with health conditions haven’t been established unambiguously.

However, smoking regularly does damage to the large airways and can lead to symptoms of chronic bronchitis (although this goes away if you stop smoking), and there are potential links with other issues such as pneumothorax and bullous lung disease, although these haven’t been clearly proven. Despite the limitations in the evidence at present, it stands to reason that smoking cannabis is harmful to the lungs. However, it appears much less dangerous to the lungs than tobacco smoking.

That said, smoking is not the only way to consume cannabis. By vaping or using edibles, you can drastically reduce (in the case of vaping) or completely remove (for edibles) the risks of cannabis when it comes to lung health.

For: Cannabis is Safer than Alcohol or Tobacco, and Those are Legal

Cannabis flower and joints with bottle of Whiskey

It’s hard to avoid the conclusion that cannabis is safer than alcohol. For example, the CDC reports that excessive alcohol consumption is responsible for over 95,000 deaths per year in the US. While it’s probable that (like alcohol), cannabis use can contribute to driving-related and work-related accidental deaths, it’s debatable whether use of cannabis alone leads to any deaths. Similarly, there is a litany of health issues linked to drinking, while using cannabis (especially through safer methods such as edibles or vaping) has some potential health issues but the links are generally unclear and in need of further research.

One factor is that alcohol is more extensively researched than cannabis, but overall it’s pretty clear that cannabis is unlikely to be found to pose risks at anywhere near the same level. The arguments in comparison to tobacco are even easier to make: the annual death toll of over 480,000 in the US alone makes this pretty clear.

Against: Cannabis Leads to Mental Health Issues Such as Schizophrenia

While finding precise answers on this issue is challenging because of limitations in the research (making it difficult to clearly establish causality) and the still-small number of studies, most researchers believe that THC (the psychoactive component of cannabis) can cause psychosis and schizophrenia. However, it seems that this is mainly the case for people with a pre-existing susceptibility to these issues, and is related to other factors such as how frequently you use cannabis and the age at which you first used it.

That said, THC is still a major risk factor for developing psychosis and schizophrenia, and the link is stronger when people use higher-THC marijuana. Since these are serious and life-altering issues, the risks of cannabis for these conditions is a powerful argument against its use.

For: Using Cannabis is a Victimless Crime

Using cannabis doesn’t impact anybody apart from (possibly) the user themselves. While this isn’t an argument for using cannabis as an individual, it’s a powerful argument against the criminalization of users: based on the harm principle, which basically states that “your freedom to swing your first ends where my nose begins.”

In short, since using cannabis doesn’t impact anybody apart from the user, there is no justification for limiting people’s ability to do so if that’s what they want. Laws in most places in the world don’t really take this into account when it comes to drugs, but it’s still a powerful argument for legalization.

Against: Cannabis is a Gateway to Other, Harder Drugs

One of the most common arguments against cannabis is that people who use it are more likely to progress to using “harder” drugs (such as heroin and cocaine) in the future. These arguments are generally supported by studies showing an association between using cannabis and using other drugs. In short, people who use cannabis are more likely to use other drugs too. The argument then goes that if a young person uses drugs, he or she will then start using harder drugs with more substantial risks.

This is a fairly difficult argument to support, though, because there is a competing hypothesis that explains the same data. It could be that some people are more likely to use any drugs, rather than the use of one causing the use of the other, the associations observed represent pieces of a cluster of behaviors stemming from a common cause. For example, someone with mental health issues could try smoking cannabis for relief, but find it lacking, then start taking opioid painkillers. In this formulation, the cannabis didn’t cause the opiate use, the mental health issues caused both. This is called “common liability.”

For: Legalizing Cannabis Generates Money for Local Governments

Along with the use of cannabis being a victimless crime, it’s unavoidably true that regulating and taxing the supply of cannabis generates large amounts of money for local government. Turning the drug use (which exists in society whether or not it’s legal) into an industry creates jobs, frees up police time and generates revenue. For example, in Colorado in 2019, the state took more than $302 million in taxes from over $1.7 billion in sales. It makes perfect sense, since it opens up a new legal market that there is obviously substantial demand for.

Against: Cannabis is Addictive

While many people believe cannabis isn’t addictive, this isn’t true. In fact, research shows that around 10% of people who use marijuana will develop a dependence on it. This means that stopping use will lead to withdrawal symptoms such as irritability, decreased appetite, cravings, sleep difficulties, restlessness and more.

People who start using marijuana earlier are more likely to develop an addiction, with up to 17% who start using in their teens will develop a dependence on it. This is also worsened by the increasing strength of cannabis in recent years as measured by THC content.

For: Addiction Should be Treated Medically, Not Punished

While it doesn’t dispute the argument that cannabis can lead to dependence, people with such issues are not helped by being punished as criminals. For all drugs – not just weed – researchers and policy experts have been arguing against criminalization and the “war on drugs” for decades. You can scarcely find a report on the issues which doesn’t recommend decriminalization of use, in a way similar to how the issues are treated in Portugal.

It’s certainly the case that addiction is a possible negative outcome, but – as with alcohol – we should recognize that punishing those for their addiction isn’t useful: they need psychological support to overcome their addiction. 

Against: Cannabis Fuels the Drug Trade

This argument basically runs: since cannabis is the most popular illegal drug, it’s a key factor in maintaining the drug trade, which is responsible for gang activity, countless deaths and suffering in many other forms. Without cannabis, a major source of funds for drug traffickers would be taken away, thus reducing the damage it causes.

The big problem with this argument is probably obvious: if it was legal, then the result would be the same as if people simply stopped using it. So while it’s true, the argument could equally be made for legalization. The pro legalization version would be more defensible too, because the only way to stop the trade otherwise is for everyone to collectively stop using cannabis, which seems unlikely to say the least.

For: Cannabis Has Many Medical Uses

Despite being a drug – and still Schedule I federally – cannabis (both THC and CBD, to be specific) has medical benefits that are recognized by a majority of states. Legally, this makes the Schedule I classification inappropriate, because it stipulates no accepted medical usage, but more broadly it’s still a strong argument for cannabis.

Cannabis has medical benefits for many conditions, and while in some cases there is only limited evidence, the situation for specific conditions and cannabinoids – for example, Dravet syndrome and CBD or a combination of THC and CBD for pain – has led many states and even the FDA (in the Dravet syndrome case) to acknowledge the medical benefits. Combined with the pretty mild risk profile, this is yet more reason that cannabis can be a net positive for society.

Against: Cannabis Impacts Developing Teen Brains/Makes You Dumb

A pretty classic argument against cannabis is the “this is your brain on drugs” type of claim, where a young, promising student starts smoking cannabis and is transformed into a lazy idiot. Of course this is an extreme version; the more sensible wording would be something like: cannabis has negative effects on adolescent brain development and cognition, lasting beyond the acute effects. There are even studies that appear to show just this, and of course if it was true this would be a compelling reason for people (young people in particular) to not use cannabis.  

There are some nuances to consider here, though, especially the impact of abstinence on these results. If the cannabis users participating in the studies haven’t been abstinent for very long, then it could still be affecting their functioning even if they aren’t actively high at the point of the test. Studies that only consider those who were abstinent from cannabis for 72 hours prior to the test don’t find significant differences between users and non-users.


The arguments for and against cannabis may tread familiar ground, but it’s useful to see them all laid out and consider the evidence supporting each position. On one side, there are concerns about the use of potentially addictive drugs – even if the risk profile is generally low – while on the other there are more liberal attitudes that emphasize individual freedom of choice even if the choices themselves aren’t perfect. In this debate, an important thing to remember is that nobody wants people harming themselves, and even those against the use of cannabis often support the freedom of choice on an individual level. Our similarities are almost certainly greater than our differences.