Cannabis, Psychosis, and Poor Journalism

In a recent article, the Independent, a UK-based newspaper, published an article titled “Why do we so consistently underplay the links between cannabis and psychosis? This isn't a benevolent drug”, written by Patrick Cockborn.

In this article, Patrick Cockborn makes the claim that there is an absolutely clear causal link between cannabis use and psychosis. He further promotes the argument that because it has risk, it should continue to be illegal and impossible to study for its benefits saying: “A new legal market in cannabis might be regulated and the toxicity of super-strength skunk reduced. But the argument of those who want to legalise cannabis is that the authorities are unable to enforce regulations when the drug is illegal, so why should they be more successful in regulating it when its production and sale is no longer against the law?”

Prohibiting any legal form of use of cannabis relegates it to the black market, which is impossible to control or eliminate.  However, just because a drug is legal for sale or medicinal use does not mean that it cannot be regulated.  The entire purpose of the FDA and other organizations is to establish a regulatory framework for the study and medical use of drugs that pose potential harm unless used properly.  Whether we regulate cannabis under the FDA as a drug or classify it specially in another manner, governments can regulate its sale without making it subject to imprisonment.  Patrick is saying that it is impossible for cannabis to be regulated in a similar manner to how opiates or even alcohol are legally regulated and is making a Straw Man fallacy argument that does not endure any sort of scrutiny.   Legalizing cannabis in a rational regulatory framework will shine a light on both its risks and benefit but keeping it in the illegal dark will not improve safety nor mitigate risk in any form.

In addition to making Straw Man arguments, he also cites another Independent article to “prove” this supposed link between cannabis and psychosis that does not, in fact address any link between cannabis and psychosis, but instead links psychosis to an autoimmune disorder. Although the author is sloppy in providing both argument and evidence, there are good studies that do suggest a possible causal link between cannabis and schizophrenia or psychosis or psychotic events- here is one example.  However, even if these proposed linkages between cannabis use and psychosis are true it should not preclude its rational medicinal use nor preclude changing its legal status.

One of the first rules of scientific inquiry is to realize correlation does not imply causation.  Just because two events occur in at a similar time does not imply that the one caused the other.  To tell if a relationship is causal is a non-trivial problem that requires in depth study and elimination of confounding variables.

There may in fact be a link between cannabis use and schizophrenia, psychosis, or psychotic events,  but this proposed link requires further study.  However, most nations' laws prevent the open and rational study of cannabis-derived compounds, making it impossible to exercise clear scientific judgment in a classic catch-22 situation.  Arguably, governments have inappropriately classified cannabis as schedule 1 despite clear and present evidence that cannabis and its derivatives are medically useful and of relatively low potential for dependence, addiction and abuse (especially relative to other medically useful drugs such as opiates, benzodiazepines, and amphetamines).  Governments are misusing their own classification system in order to prohibit cannabis study.

In another example of the Straw Man fallacy, the author seems to argue that because cannabis is not 100% “benevolent” and risk-free, we should not legalize its medicinal use.  No medication in any form is 100% benevolent.  To argue that cannabis should not be used medically because it poses risks- risks that can be mitigated- ignores the risks inherent to the use of all medication.  To use this argument to support cannabis' continued illegal status and the imprisonment of millions of people is irresponsible and ignores the societal cost of imprisoning millions of people and the subsequent lifelong effects of their incarceration.  It also ignores the clear and present medical benefits of cannabis and cannabis-derived compounds.

The first thing you have to realize about all medications is that they are the controlled use of poison.  All medications have risks and rewards in the treatment or mitigation of disease that have to be weighed and evaluated.  Aspirin can kill you by increasing bleeding risk, birth control can increase stroke and heart attack risks under certain circumstances, warfarin is incredibly deadly and difficult to manage but is still useful, and benzodiazepines and opiates are killing tens of thousands per year and the rates are only increasing.  That does not mean we cannot use those medications but we have to take professional care in their use and this is what medical professionals such as doctors, nurses, and pharmacists do. 

I am not arguing that there is no link between cannabis use and schizophrenia, psychosis, or psychotic events nor that any evidence of such should be ignored.  I am arguing that this link should be studied further but, in order to do the research, I am arguing we have to change cannabis' status so that we can study it and honestly evaluate its risks and benefits.  If schizophrenia or psychotic events are a substantial risk for some vulnerable people, then we can contraindicate THC use in those individuals without preventing its medical use generally.  That is rational use of medication.

Of further consideration, CBD significantly reduces the side effects of THC which may include sedation, paranoia, memory impairment, dizziness, psychosis, and others.  CBD may be a useful compound that we can use to mitigate the risk of THC use for patients predisposed to these conditions and may even be useful as an antidote in the case of THC overdose.  So, through the rational use of medication and the use of inhibitors such as CBD, we can mitigate the small risk to the general population.

Yes, cannabis used medically or recreationally has risk.  However, cannabis toxicity and risk are orders of magnitude less than those of other commonly used medications and substances.  Alcohol, tobacco, benzodiazepines, opiates, and other medications are vastly more harmful than cannabis and yet are not in the same legal class as cannabis.  We absolutely need to change cannabis' legal status to allow medical use and develop rational guidelines for its use.  Arguing that we should continue to treat cannabis as though it is as dangerous to public health as heroin or methamphetamine is socially and medically irresponsible and has consequences that far outweigh changing its status.  Arguing to maintain the status quo damages millions of lives, costs billions of dollars, and ignores the fact that researching cannabis could lead to the development of entirely new classes of medications.

Ethan Carruthers