Cannabis may not be suitable for all patients. Several publications from Health Canada, the CFPC, and others, have identified a set of special-risk populations in the context of both medical and recreational cannabis use. 1,2,3,4,5,6,7,8 More Level 1 research is needed on both the therapeutic and adverse effects of cannabis for specific presentations and populations.
This resource provides an overview of the risks of cannabis use in the following commonly-cited populations:
This resource also includes a note on cannabis use and the increased risk of psychosis and psychotic disorder in the general population.
1 Hodgson, C, Zacharias R. Who shouldn’t use cannabis?: Evidence Brief. Michael G. DeGroote Centre for Medical Cannabis Research. Hamilton, ON; 2017. [cited 26 Sep 2018].
2 Fischer B, Russell C, Sabioni P, van den Brink W, Le Foll B, Hall W, et al. Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations. Public Health Policy. 2017;107(8):e1-e12.
3 Kahan M, Srivastava A, Spithoff S, Bromley L. Prescribing smoked cannabis for chronic noncancer pain. Canadian Family Physician. 2014;60:1083-1090.
4 Government of Canada. Is cannabis safe to use? Facts for young adults aged 18-25 years: Cannabis evidence Brief. Health Canada. Ottawa, ON; 2018 [cited 26 Sep 2018].
5 Government of Canada Evidence Brief: Is cannabis safe to use? Facts for youth aged 13-17 years: Cannabis evidence Brief. Health Canada. Ottawa, ON; 2018 [cited 26 Sep 2018].
6 Government of Canada Evidence Brief: Is cannabis safe during preconception, pregnancy, and breastfeeding?: Cannabis evidence Brief. Health Canada. Ottawa, ON; 2018 [cited 26 Sep 2018].
7 Lenroot RK, Giedd JN. Brain development in children and adolescents: Insights from anatomical magnetic resonance imaging. Neurosci Biobehav Rev 2006;30(6):718–29.
8 Government of Canada. Does cannabis use increase the risk of developing psychosis or schizophrenia?: Cannabis evidence brief. Health Canada. Ottawa, ON; 2018 [cited 26 Sep 2018].
9 Porath AJ, Konefal S, Kent P. Clearing the smoke on cannabis: Maternal cannabis use during pregnancy—an update. Ottawa, ON: Canadian Centre on Substance Use and Addiction; 2018 [cited Sep 24 2018].
10 Gunn JK, Rosales CB, Center KE, Nunez A, Gibson SJ, Christ C, Ehiri JE. Prenatal exposure to cannabis and maternal and child health outcomes: A systematic review and meta-analysis.BMJ Open 2016 Apr 5; 6(4):e009986,2015-009986
11 Fried P. Ottawa Prenatal Prospective Study, 1995, 2002.
12 Day N, Richardson G. Maternal Health Practices and Child Development Study, 1991.
13 Chabarria KC, Racusin DA, Antony KM, et al. Marijuana use and its effects in pregnancy. Am J Obstet Gynecol 2016;215:506.e1-7.
14 El Marroun H, Tiemeier H, Steegers E, Jaddoe V, Hofman A, Velhulst FC. Intrauterine cannabis exposure affects fetal growth trajectories: The generation R study. Journal of the American Academy of Child & Adolescent Psychiatry Dec 2009; 48(11): 1173-1181.
15 Liston J. Breastfeeding and the use of recreational drugs--alcohol, caffeine, nicotine and marijuana. Breastfeed Rev 1998 Aug;6(2):27-30.
16 Djulus J, Moretti M, Koren G. Marijuana use and breastfeeding. Can Fam Physician. 2005 Mar 10; 51(3): 349–350.
17 Klonoff-Cohen HS, Natarajan L, Chen RV. A prospective study of the effects of female and male marijuana use on in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) outcomes. Am J Obstet Gynecol 2006 Feb;194(2):369-76
18 Brents LK. Marijuana, the endocannabinoid system and the female reproductive system. Yale J Biol Med 2016 Jun 27;89(2):175-91. 15.
19 Sharma R, Biedenharn KR, Fedor JM, Agarwal A. Lifestyle factors and reproductive health: Taking control of your fertility. Reprod Biol Endocrinol 2013 Jul 16;11:66,7827-11-66
20 Gundersen TD, Jorgensen N, Andersson AM, Bang AK, Nordkap L, Skakkebaek NE, Priskorn L, Juul A, Jensen TK. Association between use of marijuana and male reproductive hormones and semen quality: A study among 1,215 healthy young men. Am J Epidemiol 2015 Sep 15;182(6):473-81.
21 Grant CN, Belanger RE, Canadian Paediatric Society, Adolescent Health Committee. Position Statement: Cannabis and Canada’s children and youth. Paediatr Child Health 2017;22(2):98-102. [cited Sep 21 2018].
22 Jacobus J, Tapert SF. Effects of cannabis on the adolescent brain. Curr Pharm Des. 2014;20(13): 2186–2193.
23 Lisdahl KM, Gilbart ER,Wright NE, Shollenbarger S. Dare to delay? The impacts of adolescent alcohol and marijuana use onset on cognition, brain structure, and function. Front Psychiatry. 2013;4:53.
24 Volkow ND, Swanson JM, Evins AE, et al. Effects of cannabis use on human behavior, including cognition, motivation, and psychosis: A Review. Jama Psychiatry 2016 73 (3): 292-97.
25 Rieder MJ. Is the medical use of cannabis a therapeutic option for children? Canadian Pediatric Society Position Statement. Paediatr Child Health 2016; 21 (1): 31-34.
26 Turner SD, Spithoff S, Kahan M. Approach to cannabis use disorder in primary care: Focus on youth and other high-risk users. Can Fam Physician 2014;60(9):801–8, e423–32.
27 Volkow ND, Baler RD, Compton WM, Weiss SR . Adverse health effects of marijuana use. N Engl J Med 2014;370(23):2219–27.
28 Buckner JD, Schmidt NB, Lang AR , Small JW, Schlauch RC, Lewinsohn PM. Specificity of social anxiety disorder as a risk factor for alcohol and cannabis dependence. J Psychiatr Res 2008;42(3):230–9.
29 Cornelius JR , Kirisci L, Reynolds M, Clark DB, Hayes J, Tarter R . PTSD contributes to teen and young adult cannabis use disorders. Addict Behav 2010;35(2):91–4.
30 Johns A. Psychiatric effects of cannabis. Br J Psychiatry 2001;178:116–22.
31 D’Souza DC, Perry E, MacDougall L, et al. The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: Implications for psychosis. Neuropsychopharmacology 2004;29(8):1558–72.
32 Arendt M, Rosenberg R , Foldager L, Perto G, Munk-Jørgensen P. Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: Follow-up study of 535 incident cases. Br J Psychiatry 2005;187(6):510–5.
33 Lynskey MT, Coffey C, Degenhardt L, Carlin JB, Patton G. A longitudinal study of the effects of adolescent cannabis use on high school completion. Addiction 2003;98(5):685–92.
34 Brook JS, Stimmel MA, Zhang C, Brook DW. The association between earlier marijuana use and subsequent academic achievement and health problems: A longitudinal study. Am J Addict 2008;17(2):155–60.
35 Large M, Sharma S, Compton MT, Slade T, Nielssen O. Cannabis use and earlier onset of psychosis: A systematic meta-analysis. Arch Gen Psychiatry 2011 Jun;68(6):555-61.
36 Radhakrishnan R, Wilkinson ST, D'Souza DC. . Gone to pot - A review of the association between cannabis and psychosis. Front Psychiatry 2014 May 22;5:54.
37 Di Forti M, Sallis H, Allegri F, Trotta A, Ferraro L, Stilo SA, Marconi A, La Cascia C, Reis Marques T, Pariante C, et al. Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users. Schizophr Bull 2014 Nov;40(6):1509-17.
38 Helle S, Ringen PA, Melle I, Larsen TK, Gjestad R, Johnsen E, Lagerberg TV, Andreassen OA, Kroken RA, Joa I, et al. Cannabis use is associated with 3 years earlier onset of schizophrenia spectrum disorder in a naturalistic, multi-site sample (N=1119). Schizophr Res 2016 Jan;170(1):217-21.
39 Batalla A, Bhattacharyya S, Yucel M, Fusar-Poli P, Crippa JA, Nogue S, Torrens M, Pujol J, Farre M, Martin-Santos R. Structural and functional imaging studies in chronic cannabis users: A systematic review of adolescent and adult findings. PLoS One 2013;8(2):e55821.
40 Moore TH, Zammit S, Lingford-Hughes A et al. Cannabis use and risk of psychotic or affective mental health outcomes: A systematic review. Lancet 2007 Jul; 370 (9584): 319-28.
41 McGrath J, Welham J, Scott J, et al. Association between cannabis use and psychosis-related outcomes using sibling pairanalysis in a cohort of young adults.Arch Gen Psychiatry. 2010;67(5):440–447.
42 Di Forti M, Quattrone D, Freeman TP et al. The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicenter case-control study. The Lancet Psychiatry 2019 Mar; 2215-0366(19):30048-3.
43 Marconi A, Di Forti M, Lewis CM, Murray RM, Vassos E. Meta-analysis of the association between the level of cannabis use and risk of psychosis. Schizophr Bull 2016 Feb 15.
44 Fergusson DM, Horwood LJ, Ridder EM. Tests of casual linkages between cannabis use and psychotic symptoms. Addiction 2005 Mar;100(3):354-66.
45 Di Forti M, Morgan C, Dazzan P et al. High-potency cannabis and the risk of psychosis. The British Journal of Psychiatry . 2009 Dec; 195(6):488-491.
46 Government of Canada. Is cannabis addictive? Cannabis evidence Brief. Health Canada. Ottawa, ON; 2018 [cited 4 Apr 2019].