ArticleCMAJ open
The adverse health effects and harms related to marijuana use: an overview review.
Article in CMAJ open. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 54 papers, 4 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
54 citing papers in PubMed, 4 syntheses or guidelines pooled it.
- Digital Interventions for Recreational Cannabis Use Among Young Adults: Systematic Review, Meta-Analysis, and Behavior Change Technique Analysis of Randomized Controlled Studies.Journal of medical Internet research · 2024Pooled it
- Medical Cannabis and Its Efficacy/Effectiveness for the Treatment of Low-Back Pain: a Systematic Review.Current pain and headache reports · 2023Pooled it
- Measuring white matter microstructure in 1,457 cannabis users and 1,441 controls: A systematic review of diffusion-weighted MRI studies.Frontiers in neuroimaging · 2023Pooled it
- Long-term and serious harms of medical cannabis and cannabinoids for chronic pain: a systematic review of non-randomised studies.BMJ open · 2022Pooled it
- Acceptability, Feasibility, and Outcome Responsiveness of the Joint Effort Mobile App for Promoting Lower-Risk Cannabis Use Among Young Adults: Pilot Randomized Controlled Trial.JMIR mHealth and uHealth · 2026Trial
- Characterizing Online Questions and Answers About Cannabis Use and Pregnancy on the Social Media Platform Quora: Data Mining and Qualitative Content Analysis.Journal of medical Internet research · 2026Article
- Adherence to Lower-Risk Cannabis Use Guidelines among Canadian college students: a regression analysis.Health promotion and chronic disease prevention in Canada : research, policy and practice · 2026Article
- Associations Among Minority Stress, Relaxation and Tension-Reduction Motives, and Cannabis Use Among a Sample of Sexual and Gender Minority Adults in Oklahoma.Substance use & addiction journal · 2026Article
- In Vitro Exposure to Vaped Tetrahydrocannabinol IncreasesMicroorganisms · 2025Article
- Cannabis-Associated Emergencies in the Emergency Department.Deutsches Arzteblatt international · 2025Review
- Trends in cannabis-attributable hospitalizations and emergency department visits: data from the Canadian Substance Use Costs and Harms Study (2007-2020).Health promotion and chronic disease prevention in Canada : research, policy and practice · 2025Article
- The intersection of cannabis use and oral health among 2SLGBTQI+ youth: a qualitative study protocol.BMC oral health · 2025Article
- Recreational drugs repurposed for medicinal use-cannabis.CNS spectrums · 2025Review
- Article
- Review
- Trends in Prevalence of Cannabis Use Disorder Among U.S. Veterans With and Without Psychiatric Disorders Between 2005 and 2019.The American journal of psychiatry · 2024Article
- Cannabis Use Differences Among Sexual Minority Versus Heterosexual Females and Males in Oklahoma: The Roles of Mental Health, Cannabis Perceptions, and Cannabis Marketing Exposure.Substance use & addiction journal · 2024Article
- Disparities in Cannabis Use among Female and Male Sexual Minority Young Adults in the US: The Role of Parenting Behaviors.Cannabis (Albuquerque, N.M.) · 2024Article
- Disparities in cannabis use outcomes, perceived risks and social norms across sexual orientation groups of US young adult women and men.Health education research · 2023Article
- Cannabis Use Among U.S. Military Veterans Following Residential Substance Use Disorder Treatment.Military medicine · 2023Article
Corrections and comments
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Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundWith impending marijuana legislation in Canada, a broad understanding of the harms associated with marijuana use is needed to inform the clinical community and public, and to support evidence-informed public policy development. The purpose of the review was to synthesize the evidence on adverse health effects and harms of marijuana use.
methodsWe searched MEDLINE, The Cochrane Database of Systematic Reviews, Embase, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature, and the Health Technology Assessment Database from the inception of each database to May 2018. Given that systematic reviews evaluating one or other specific harm have been published, this is an overview review with the primary objective of assessing a health effect or harm. Data on author, country and year of publication, search strategy and results, and outcomes were extracted. Quality was assessed using the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist.
resultsThe final analysis included 68 reviews. Evidence of harm was reported in 62 reviews for several mental health disorders, brain changes, cognitive outcomes, pregnancy outcomes and testicular cancer. Inconclusive evidence was found for 20 outcomes (some mental health outcomes, other types of cancers and all-cause mortality). No evidence of harm was reported for 6 outcomes.
interpretationHarm was associated with most outcomes assessed. These results should be viewed with concern by physicians and policy-makers given the prevalence of use, the persistent reporting of a lack of recognition of marijuana as a possibly harmful substance and the emerging context of legalization for recreational use.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.