The cannabis paradox

This month, Canadian Family Physician is publishing a systematic review of studies evaluating the use of medical cannabinoids (page e78).¹ After identifying 1085 articles and retaining 31 relevant publications, the authors arrived at the following conclusions: reasonable evidence exists to support the use of cannabinoids for treating nausea and vomiting associated with chemotherapy; these products might improve spasticity, particularly in multiple sclerosis; and it is uncertain whether cannabinoids are capable of relieving pain, although if they do they only relieve neuropathic pain (with rather modest benefits). However, adverse effects frequently occur, to the point where the authors indicated that the anticipated benefits must be very high before considering the use of these products. They also add the following:

The evidence indicates the most consistent effects of medical cannabinoids are adverse events. A variety of adverse events have a greater magnitude of effect than the potential benefits for the conditions targeted.¹

The conclusions drawn by this analysis are not surprising. Study after study, analysis after analysis, and review after review^2,3 have all reported the same findings: cannabis has little place within current therapeutic arsenals, except as a last resort in very specific situations or when nothing else has worked.

Despite this, some continue to maintain that cannabinoids could improve users’ quality of life. However, a recent publication has contradicted this belief. The results of this meta-analysis have concluded that it is not possible to establish a relationship between health-related quality of life and the consumption of cannabis.⁴

Normally, when faced with similar results, we would have stopped dallying over the potential benefits of cannabis and cannabinoids, and closed this debate once and for all. If these products are so ineffective (or only marginally effective), generate so many adverse effects, and do nothing for quality of life, there is no reason to use them except in very specific circumstances. Is that not what we would say in the case of any other substance?

But not with cannabis and cannabinoids!

In this case, there is always a thousand and one reasons to believe (or pretend?) that this substance could be useful in this or that situation. The arguments are always the same: not enough research, insufficient evidence, inhaled marijuana versus cannabinoids, more tetrahydrocannabinol and less cannabidiol, less tetrahydrocannabinol and more cannabidiol … and who knows what else!

But the strangest aspect of this story is certainly its social paradox. If cannabis is ineffective, generates so many adverse effects, and does not improve quality of life, why do 3.4 million Canadians consume it every year?⁵ Why do these individuals continue to smoke weed when they do not even know its origins? Why do they keep paying for a substance of which they do not know the composition, and keep exposing themselves to the judicial risks associated with its production, possession, and consumption?

For its recreational use, you say? Alright. But what do we mean by recreational use? Undoubtedly, most consumers use it for its psychotropic effects, just as with any other drug, tobacco and alcohol included. They need the excitement, euphoria, or sedation associated with the substance; they are seeking out a sense of well-being, even if fleeting. Why else would they consume an ineffective and useless substance, and why else would they pay for it? This is the paradox. Regardless of what the science tells us, people will continue to consume cannabis.

Consequently, it is in the interest of family physicians to familiarize themselves with cannabinoids, just as they have with tobacco, alcohol, and other psychotropic drugs, to better equip themselves to counsel and assist those among their patients who use them. It is irrelevant whether the substance is being used for medical or recreational purposes.

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