Cannabis contains over a hundred of different cannabinoids, of which Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most well studied. The use of high-potency cannabis, containing high concentrations of THC and low concentrations of CBD, has been linked to adverse health outcomes, particularly for adolescents and young adults. Recently, an increase in cannabis potency has been observed in jurisdictions that legalized the sale of cannabis for non-medical purposes. Moreover, an increase of cannabis use and cannabis-related emergency treatment have also been observed in these jurisdictions. At the same time, risk perception regarding cannabis use has decreased in these populations. Trivializing language and an increased appearance of commercial cannabis in the public space may lead to a generalized underestimation of the risks of cannabis use. New regulation models principally focus on the creation of a legal cannabis market economy, the diversion of profits from illegal markets, and the reduction of costs associated with prohibition. However, an approach that specifically focuses on the rights to the health and safety of the individual should be considered in order to reduce the risks associated with cannabis legalization. Such an approach should promote and protect individual and social health and safety, establish a strict quality control of legal cannabis products regulated according to THC and CBD content, and eliminate all sorts of incentives to use, thus providing a more consistent, sustainable, and ethical framework for the legalization of non-medical cannabis use.
EnglundAFreemanTPMurrayRM, et al.
Can we make cannabis safer?Lancet Psychiatry2017;
4: 643–648.
2.
WeissSRBHowlettKDBalerRD.Building smart cannabis policy from the science up.Int J Drug Policy2017;
42: 39–49.
3.
ElSohlyMAMehmedicZFosterS, et al.
Changes in cannabis potency over the last 2 decades (1995–2014): analysis of current data in the United States. Biol Psychiatry2016;
79: 613–619.
4.
ChandraSRadwanMMMajumdarCG, et al.
New trends in cannabis potency in USA and Europe during the last decade (2008–2017).Eur Arch Psychiatry Clin Neurosci2019;
269: 5–15.
5.
MurrayRMQuigleyHQuattroneD, et al.
Traditional marijuana, high-potency cannabis and synthetic cannabinoids: increasing risk for psychosis.World Psychiatry2016;
15: 195–204.
6.
SmartRCaulkinsJPKilmerB, et al.
Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state.Addiction2017;
112: 2167–2177.
7.
ZamengoLFrisonGBettinC, et al.
Variability of cannabis potency in the Venice area (Italy): a survey over the period 2010–2012. Drug Test Anal2014;
6: 46–51.
8.
ZamengoLFrisonGBettinC, et al.
Cannabis potency in the Venice area (Italy): update 2013.Drug Test Anal2015;
7: 255–258.
9.
DujourdyLBesacierF.A study of cannabis potency in France over a 25 years period (1992–2016). Forensic Sci Int2017;
272: 72–80.
10.
FreemanTPGroshkovaTCunninghamA, et al.
Increasing potency and price of cannabis in Europe, 2006–16.Addiction2019;
114: 1015–1023.
11.
Di FortiMSallisHAllegriF, et al.
Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users. Schizophr Bull2014;
40: 1509–1517.
12.
Di FortiMMarconiACarraE, et al.
Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: a case-control study. Lancet Psychiatry2015;
2: 233–238.
13.
FreemanTPWinstockAR.Examining the profile of high-potency cannabis and its association with severity of cannabis dependence. Psychol Med2015;
45: 3181–3189.
14.
MeierMH.Associations between butane hash oil use and cannabis-related problems. Drug Alcohol Depend2017;
179: 25–31.
15.
FreemanTPvan der PolPKuijpersW, et al.
Changes in cannabis potency and first-time admissions to drug treatment: a 16-year study in the Netherlands. Psychol Med2018;
48: 2346–2352.
16.
Di FortiMQuattroneDFreemanTP, et al.
The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. Lancet Psychiatry2019;
6: 427–436.
17.
WangGSDaviesSDHalmoLS, et al.
Impact of marijuana legalization in Colorado on adolescent emergency and urgent care visits. J Adolesc Health2018;
63: 239–241.
18.
BoaduOGombolayGYCavinessVS, et al.
Intoxication from accidental marijuana ingestion in pediatric patients: what may lie ahead. Pediatr Emerg Care. Epub ahead of print, 5 February 2018. DOI: 10.1097/PEC.0000000000001420.
19.
HallWDPattonGStockingsE, et al.
Why young people’s substance use matters for global health. Lancet Psychiatry2016;
3: 265–279.
20.
VolkowNDBalerRDComptonWM, et al.
Adverse health effects of marijuana use.N Engl J Med2014;
370: 2219–2227.
21.
DegenhardtLCharlsonFFerrariA, et al.
The global burden of disease attributable to alcohol and drug use in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Psychiatry2018;
5: 987–1012.
22.
SchettinoJLeuschnerFKastenL, et al. Treatment of cannabis-related disorders in Europe. EMCDDA Insights no. 17, 2015.
Luxembourg:
Publications Office of the European Union.
23.
ComptonWMHanBJonesCM, et al.
Marijuana use and use disorders in adults in the USA, 2002–14: analysis of annual cross-sectional surveys. Lancet Psychiatry2016;
3: 954–964.
24.
WilsonJFreemanTPMackieCJ.Effects of increasing cannabis potency on adolescent health. Lancet Child Adolesc Health2019;
3: 121–128.
CerdáMMauroCHamiltonA, et al.
Association between recreational marijuana legalization in the United States and changes in marijuana use and cannabis use disorder from 2008 to 2016. JAMA Psychiatry2020;
77: 165–171.
28.
GoodwinRDPacekLRCopelandJ, et al.
Trends in daily cannabis use among cigarette smokers: United States, 2002–2014. Am J Public Health2018;
108: 137–142.
29.
Salas-WrightCPVaughnMGCummings-VaughnLA, et al.
Trends and correlates of marijuana use among late middle-aged and older adults in the United States, 2002–2014. Drug Alcohol Depend2017;
171: 97–106.
30.
HallW.What has research over the past two decades revealed about the adverse health effects of recreational cannabis use?Addiction2015;
110: 19–35.
31.
AsbridgeMHaydenJACartwrightJL.Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analysis.BMJ2012;
344: e536.
32.
Rocky Mountain High Intensity Drug Trafficking Area. The legalization of marijuana in Colorado: the impact. Vol.
5, September 2018. Denver: Rocky Mountain HIDTA Strategic Intelligence Unit.
33.
National Academies of Sciences, Engineering, and Medicine. The health effects of cannabis and cannabinoids: the current state of evidence and recommendations for research.
Washington, DC:
The National Academies Press, 2017.
BullSSBrooks-RussellADavisJM, et al.
Awareness, perception of risk and behaviors related to retail marijuana among a sample of Colorado youth.J Community Health2017;
42: 278–286.
37.
CerdáMWallMFengT, et al.
Association of state recreational marijuana laws with adolescent marijuana use.JAMA Pediatr2017;
171: 142–149.
38.
McNeelyJHalkitisPNHortonA, et al.
How patients understand the term ‘nonmedical use’ of prescription drugs: insights from cognitive interviews. Subst Abus2014;
35: 12–20.
39.
GarretsenHFLBlomTvan de BuntH, et al. Drugs in lijsten. Rapport Expertcommissie Lijstensystematiek Opiumwet, June 2011. Rijswijk: VijfkeerBlauw.
40.
JanikPKosticovaMPecenakJ, et al.
Categorization of psychoactive substances into ‘hard drugs’ and ‘soft drugs’: a critical review of terminology used in current scientific literature.Am J Drug Alcohol Abuse2017;
43: 636–646.
41.
United Nations Office on Drugs and Crime. World Drug Report2018. United Nations publications, sales no. E.18.XI.9, June 2018. New York: United Nations.
42.
HughesBMatiasJGriffithsP.Inconsistencies in the assumptions linking punitive sanctions and use of cannabis and new psychoactive substances in Europe.Addiction2018;
113: 2155–2157.
43.
Colorado Retail Marijuana Code2012(CO).
44.
Control, Regulation, and Taxation of Marijuana and Industrial Hemp Act2014(OR).
GhoshTSVigilDIMaffeyA, et al.
Lessons learned after three years of legalized, recreational marijuana: the Colorado experience.Prev Med2017;
104: 4–6.
47.
HallWLynskeyM.Evaluating the public health impacts of legalizing recreational cannabis use in the United States.Addiction2016;
111: 1764–1773.
48.
DirisuOShickleDElseyH.Influence of legal status on the uptake of cannabis in young people.Curr Opin Psychiatry2016;
29: 231–235.
49.
HallWLynskeyM.Why it is probably too soon to assess the public health effects of legalisation of recreational cannabis use in the USA. Lancet Psychiatry2016;
3: 900–906.
50.
Freeman TP and Lorenzetti V.
‘Standard THC units’: a proposal to standardize dose across all cannabis products and methods of administration. Addiction2020;
115(7): 1207–1216. 10.1111/add.14842.
