Published 23 October 2023

Legalizing the “recreational” use of cannabis would be a serious health error.

Académie nationale de médecine

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Press Release

French National Academy of Medicine

October 23, 2023

Legalizing the “recreational” use of cannabis would be a serious health error.


In a previous press release, the French Academies of Medicine and Pharmacy were concerned about a public consultation on “recreational cannabis”, with biased items (1). This approach was part of an ideological movement aimed at prioritizing a medical use in order to give this drug “therapeutic” credentials.
However, as a recent meta-analysis points out: ” Most outcomes associated with cannabinoids are supported by weak evidence (observational studies), low to very low certainty (randomised controlled trials), or are not significant (observational studies, randomised controlled trials)” (2).
Furthermore, the toxicity of the drug’s main psychotropic constituent, tetrahydrocannabinol (THC), is well established:  medical toxicity greater than that of tobacco (cancers, heart attacks, heart rhythm disorders, strokes, arteritis, etc.), psychological toxicity (cognitive and anxiodepressive disorders, amotivation syndrome, disinhibition, induction or aggravation of schizophrenia, etc.), effects on pregnancy and offsprings, epigenetic changes (3, 4). It may also lead to violence in the family, at work and on the roads (with 605 deaths in France in 2021). The 6-fold increase in THC levels in its resin over the last 25 years increases its addictive power and, as a result, the recruitment of subjects who become dependent after trying the drug; It also exacerbates its medical and psychological toxicity; we are very far from the “soft drug” which has long been presented as such (5).
This explains the growing number and severity of its adverse and toxic effects, particularly among the most vulnerable, adolescents and young adults. Its use, a source of problems among 17-year-olds, has risen, from 18% in 2011 to 25% in 2017 (5). Several studies have confirmed its harmful effects on brain maturation, which only ends around the age of 25. They show that THC use is accompanied by dependence and a drop in the intelligence quotient, which are all the more marked as its consumption is more frequent and early. While alcohol and tobacco use among pregnant women has declined, that of cannabis has increased at a worrying rate. Its deleterious effects are not limited to the user, they also affect her offspring. Consumed during pregnancy, it acts on the placenta (modifying the expression of some genes), with consequences for the fetus (altering its development), but also for the newborn (prematurity, low birth weight, risk of admission to an intensive care unit, etc.) and for the infant (increased risk of sudden death). If consumed by a future father, it may have consequences for the fetus he would generate,  which could lead to  autism spectrum disorders, psychotic  and intellectual disorders (6).
While the fight to reduce the terrible health damage caused by tobacco and alcohol is having little effect, it would be a serious error to legalize an additional source of addiction, while  the French President has set the goal of a “zero-tobacco” generation by 2032, with cannabis standing on the shoulders of tobacco.
In countries that have legalized its “recreational use”, it has been shown that this measure has not reduced either use or traffic (7). As for the hypothetical revenues from state taxes on tobacco and alcohol, they cover less than half the health costs associated with their consumption.
In the United States, where more than 30 states have legalized cannabis use, the latest data from the National Institute of Drug of Abuse show that cannabis consumption reached an all-time high in 2022 among adults of childbearing age (both for age groups of 31 to 50 and young adults aged 19 to 30), where consumption has risen steadily over the past 5 years (7). Previous studies had shown that drug use was higher in states that had legalized recreational use than in others.
Legalizing the “recreational use” of cannabis would therefore be a serious health error in terms of health, as we are not aware of all its known and potential harmful effects.

–  Bi-academic press release dated April 07, 2021.

–  Solmi M, De Toffol M, Kim JY, Choi MJ, Stubbs B, Thompson T et al. Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies. BMJ. 2023 Aug 30;382:e072348. doi: 10.1136/bmj-2022-072348

– Cotier P, Mayer C, Etting I, Lorin de la Grandmaison G, Alvarez JC. Evaluation of the cardiovascular risk induced by cannabis use from a series of 43 autopsy cases. Int J Legal Med 2023 ;137 :1725-1733. doi: 10.1007/s00414-023-03079-x.

– Costentin J. Les effets épigénétiques du cannabis/tétrahydrocannabinol. Bull Acad Natle Med 2020 ; 204 : 570-576.

– Goullé JP, Guerbet M. L’usage récréatif du cannabis : des effets aux méfaits. Données épidémiologiques. Bull Acad Natle Med 2020 ;204 :543-550. doi :10.1016/j.banm.2020.04.001.

– Lo JO, Hedges JC, Metz TD. Cannabis Use and Perinatal Health Research. JAMA. 2023; Aug 17. doi: 10.1001/jama.2023.14697.

– Marijuana and hallucinogen use, binge drinking reached historic highs among adults 35 to 50. National Institute on Drug Abuse website. August 17, 2023 Accessed September 1, 2023.

Bull Acad Natl Med 2024;208:117-8. Doi : 10.1016/j.banm.2023.12.008