Observational studyAddiction (Abingdon, England)2026
The role of perceived access to cannabis in the association between friends who use cannabis and adolescent initiation: A longitudinal analysis from the Canadian COMPASS study.
Observational study in Addiction (Abingdon, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
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
1 citing paper in PubMed.
- The role of perceived access to cannabis in the association between friends who use cannabis and adolescent initiation: A longitudinal analysis from the Canadian COMPASS study.Addiction (Abingdon, England) · 2026Observational
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
Abstract
BACKGROUND AND
aimsEarly initiation to cannabis use in adolescence is linked to cognitive and mental health risks. Having friends who use cannabis is a strong risk factor for initiation, but the mechanisms underlying this relationship are unclear. This study examined the role of perceived ease of access to cannabis in the association between close friends' cannabis use and cannabis initiation.
designObservational longitudinal investigation using data from the COMPASS study.
settingA convenience sample of 11 high schools in Québec, Canada, from 2017 to 2019.
participants1768 students who had not initiated cannabis use before 2019. MEASUREMENTS: Having ≥1 close friend who uses cannabis and perceived ease of access to cannabis were measured in 2018, while cannabis initiation in the past 12 months was assessed in 2019. Covariates measured in 2017 included sociodemographic factors, substance use history, lifestyle behaviors and school-related variables. We compared the risk of cannabis initiation across groups defined jointly by friends' cannabis use and perceived access. Generalised estimating equations with bootstrap resampling, inverse probability weighting for attrition and multiple imputation for missing data were used to estimate these associations. Natural effect models were then applied to estimate total, direct and indirect effects with initiation as the outcome and perceived access as the mediator.
findingsWithin the COMPASS cohort, 14% of cannabis-naive adolescents in 2018 initiated use in 2019. Using students with no close friends who use cannabis and who perceive access as difficult as the reference group, the risk difference (RD) for having at least one friend who uses cannabis while still perceiving access as difficult was 3.2 [95% confidence interval (CI) = -3.8 to 10.2]. Perceiving access as easy but having no friends who use cannabis yielded an RD of 8.4 (95% CI = 3.0-13.7). Friends' cannabis use combined with easy access acted synergistically, producing an RD of 21.6 (95% CI = 15.5-27.7). According to the natural effect models, perceived ease of access mediated about 39% of the association between having ≥1 close friend who uses cannabis and subsequent initiation, suggesting a possible explanatory pathway.
conclusionsIn Canada, cannabis initiation risk appears to be highest among adolescents with both exposure to close friends who use cannabis and perceived easy access. Perceived access may help explain part of this association. Preventive strategies should address the influence of friends and accessibility through school policies, public education and stricter enforcement of access restrictions to delay adolescent cannabis use.
Indexed as
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.