Cannabis and Stressor Response in MAP Settings: What Qualitative Findings Reveal
Last Updated: February 2026 | Reading Time: 5 minutes
Quantitative studies of cannabis substitution establish whether an effect exists and how large it is. Qualitative research examines how it works from the perspective of people experiencing it. The Vancouver CMAPS pilot, with High Hopes Research Society as cannabis substitution program operator, generated qualitative interview data that adds significant texture to the quantitative findings. This article reviews what those findings, alongside the published Ottawa qualitative data, reveal about participant-described mechanisms of cannabis substitution for alcohol harm reduction in managed alcohol program (MAP) settings.
Note: The Vancouver manuscript is currently in peer review at Drug & Alcohol Review and should not be cited until accepted. Qualitative findings from that work are described here as context for the published Ottawa findings, which can be cited.
Gradual Moderation, Not Immediate Replacement
The central qualitative finding across the CMAPS cannabis substitution research is that cannabis in MAP settings does not function as an acute replacement – a glass of beer swapped for a joint. Participants in both pilots described something more gradual: cannabis as a tool that allowed them to slow their alcohol use over time, reduce the urgency of craving, and establish a less chaotic daily pattern around drinking.
This aligns with the quantitative finding from Goulet-Stock et al. (2026) that the substitution effect operated through stable between-person patterns rather than daily within-person fluctuations. The qualitative data explain why: participants were not making active real-time trade-offs. They were describing a shift in their overall relationship with alcohol – one that unfolded over weeks, not days.
Quality of Life as a Parallel Outcome
Participants in both the Ottawa and Vancouver cannabis substitution pilots described quality of life improvements that accompanied the reduction in alcohol use – particularly improved sleep and appetite. Participants who described cannabis as helpful were often speaking to these dimensions as much as, or more than, direct craving reduction.
This has practical implications for how cannabis substitution programs are evaluated. Harm reduction interventions that measure only alcohol consumption as the primary outcome will capture the quantitative substitution signal but miss the quality-of-life improvements that participants themselves identify as meaningful. The Bailey et al. (2023) knowledge translation paper in the International Journal of Drug Policy documents how lived-experience co-designers specifically named these dimensions – sleep, appetite, nutritional status, social functioning – as important evaluation targets, not incidental to the harm reduction goal, but central to it.
Stressor Response and Cannabis Use in Managed Alcohol Programs
One of the more nuanced findings from the mixed-methods evaluation of the Vancouver cannabis substitution program involves how stressor events affected substance use patterns. Program records data from the 40-participant, 20-week evaluation show that cannabis use remained relatively stable even as stressor events — grief, emergency room visits, and detox episodes — were associated with substantial increases in alcohol consumption (mean increase of 27.3% during stressor weeks). For some participants, cannabis appeared to function as a background stabilizing element that moderated but did not eliminate stress-induced alcohol escalation.
When grief and ER events occurred together, the data showed notably increased alcohol consumption alongside a comparatively smaller rise in cannabis use — a pattern the authors interpret as consistent with cannabis playing a moderating role during compounded stress. The mixed-methods evaluation notes that cannabis alone did not fully mitigate alcohol increases during severe acute stress, underscoring the need for integrated mental health support alongside cannabis substitution in MAP settings.
This pattern is clinically relevant for harm reduction program design: the benefit of cannabis access in a MAP context may be most visible not during stable periods but during acute stress, where it appears to limit the ceiling on alcohol escalation rather than prevent it entirely.
The Source Distinction: Licensed vs. Street-Acquired Cannabis
A consistent finding across both Ottawa and Vancouver qualitative data is that participants distinguished meaningfully between program-provided licensed medical cannabis and street-acquired cannabis. Participants described the licensed supply as more reliable, more consistent in effect, and qualitatively different from grey-market product.
Quantitative program records from Vancouver support this: the introduction of the cannabis substitution program did not increase overall cannabis consumption among MAP clients — it redirected participants from grey-market acquisition to the licensed High Hopes supply. This source-shift finding is important for institutional decision-makers considering cannabis substitution programs, because it directly addresses a common concern: that providing cannabis in a MAP setting will simply add cannabis use on top of existing substance use patterns. The combined qualitative and quantitative evidence suggests the opposite — licensed access replaced grey-market acquisition, and alcohol use declined. The regulation and reliability of the supply, not cannabis provision per se, appears to be the operative variable.
Motivation Diversity: What Participants Wanted from the Program
The qualitative data document that participants entered the cannabis substitution program with diverse motivations, and that this diversity shaped both their experience and their outcomes. Some participants were explicitly motivated by a desire to reduce alcohol consumption. Others wanted to replace grey-market cannabis with a licensed supply they trusted. Others were primarily interested in quality of life improvements — sleep, appetite, pain, and the ability to engage in physical activity.
Outcome data from the 40-participant, 20-week evaluation reflects this diversity: 50% of participants reduced alcohol consumption over the study period, while 50% experienced increases, particularly during stressor events. This distribution is important for setting accurate institutional expectations. Cannabis substitution in MAP settings is not a uniform intervention producing a uniform result. It is a harm reduction approach that meets clients where they are, producing a range of outcomes across a cohort, with a positive population-level signal even when individual trajectories vary considerably.
The Pauly et al. (2021) feasibility study’s emphasis on personalized approaches reflects this reality: the evidence supports cannabis substitution as a population-level harm reduction tool for people with alcohol use disorder in MAP settings, not as a standardized treatment protocol with predictable individual results.
This article draws on published CMAPS findings and contextualizes in-peer-review data for a research and institutional audience. The Vancouver manuscript should not be cited until accepted.
References
- Bailey, Harps, Belcher, Williams, Amos, Graham, Goulet-Stock et al. (2023). International Journal of Drug Policy. DOI: 10.1016/j.drugpo.2023.104244
- Goulet-Stock, Hacksel, Scandiuzzi, Boyd, Pauly & Stockwell (2026). International Journal of Drug Policy, 147: 105083. DOI: 10.1016/j.drugpo.2025.105083
- Pauly, Brown, Chow, Wettlaufer, Graham, Urbanoski et al. (2021). Harm Reduction Journal, 18: 65. DOI: 10.1186/s12954-021-00512-5