Re: Cannabis use by adolescents

This article [BCMJ 2019;61:14-19] would be the first in the literature to establish different clinical effects from C. sativa and C. indica strains. While Dr Ocana insists that clinical research supports separating these strains because of their different effects (stimulating vs sedating), the reference he provided does not support this or even use these differing strain names. Recent chemical analysis of cannabis strains from Washington State argues against differences in CBD and THC between these strains.[1] Other cannabis scientists are in agreement that these terms are better suited to marketing than clinical use: “There are biochemically distinct strains of Cannabis, but the sativa/indica distinction as commonly applied in the lay literature is total nonsense and an exercise in futility.”[2]

In Dr Ocana’s article, results are presented from a cohort interviewed about their experiences with different strains; however, the results should be viewed more as those of the placebo effect in combination with observer bias, especially given the lack of quantification of the cannabis used.

Dr Ocana also states that deaths have increased with cannabis legalization. The cited reference mentions only one death, that of a child who died of myocarditis. This case was controversial enough for the case report’s authors to publicly clarify, “We are absolutely not saying that marijuana killed that child.”[3]

As Dr Ocana notes, it can be difficult to deal with misinformation; this is magnified when it is published in a medical journal. The three most commonly held misbeliefs among physicians are that cannabis overdose can be fatal, that cannabis is often contaminated with fentanyl, and that there are differences in effect between C. indica and C. sativa strains.
—Ian Mitchell, MD, FRCP
Clinical Associate Professor, UBC Department of Emergency Medicine
Site Scholar, Kamloops Family Medicine Residency Program

This letter was submitted in response to “Cannabis use by adolescents: Practical implications for clinicians.”


1.    Jikomes N, Zoorob M. The cannabinoid content of legal cannabis in Washington State varies systematically across testing facilities and popular consumer products. Scientific Reports. Accessed 26 February 2019.

2.    Piomelli D, Russo EB. The cannabis sativa versus cannabis indica debate: An interview with Ethan Russo, MD. Cannabis Cannabinoid Res 2016;1:44-46.

3.    Silverman E. The truth behind the ‘first marijuana overdose death’ headlines. The Washington Post. Accessed 26 February 2019.

Ian L. Mitchell, MD, FRCP. Re: Cannabis use by adolescents. BCMJ, Vol. 61, No. 3, April, 2019, Page(s) 110 - Letters.

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