Cannabis Co-Use Made Smokers Less Likely to Quit Cigarettes | Research

The takeaway

Among over 8,000 established cigarette smokers tracked in the PATH Study, those who also used cannabis had 19% lower odds of successfully quitting smoking compared to smokers who did not use cannabis.

Tobacco cessation clinicians, public health officials, and researchers studying the intersection of cannabis and tobacco policy.

What the researchers found

Cannabis co-use was associated with decreased odds of cigarette discontinuation (aOR: 0.81, 95% CI: 0.72-0.93, p=0.0018) and decreased odds of discontinuing all combustible tobacco products (aOR: 0.75, 95% CI: 0.65-0.86, p<0.0001). Over one-third (35.9%) of cigarette smokers reported cannabis co-use during the study, and this proportion increased over time.

Why it matters

As cannabis becomes more accessible, the proportion of cigarette smokers who also use cannabis is growing. This study reveals a previously underappreciated barrier to tobacco cessation: cannabis co-use may reduce the likelihood of quitting smoking, complicating public health efforts to reduce tobacco use.

The numbers in context

8,218 adults, 26,381 observations across 5 waves. 35.9% of smokers reported cannabis co-use. Cigarette discontinuation: aOR 0.81 (95% CI: 0.72-0.93). All combustible tobacco discontinuation: aOR 0.75 (95% CI: 0.65-0.86). Cannabis co-use increased over the study period.

How the study worked

Longitudinal analysis of 26,381 observations from 8,218 adults with established cigarette use (100+ lifetime cigarettes) across waves 1-5 of the Population Assessment of Tobacco and Health (PATH) Study. Weighted GEE models adjusted for demographics, behavioral characteristics, and substance use problems.

What this study cannot tell us

Observational design cannot prove cannabis caused lower quit rates. Cannabis users may differ from non-users in ways not captured by covariates. Self-reported cannabis and tobacco use subject to reporting biases. PATH Study waves 1-5 span a period of changing cannabis policies.

How to read the evidence

Large nationally representative longitudinal study with validated measures and appropriate statistical methods, providing strong observational evidence.

When this study was published

Published 2025, using PATH Study waves 1-5 data.

The bigger picture

This finding creates a tension between cannabis legalization and tobacco control goals. If cannabis use makes it harder to quit smoking, then the two public health issues cannot be addressed in isolation. Tobacco cessation programs may need to specifically address concurrent cannabis use.

Questions still open

Whether cannabis-specific cessation support improves tobacco quit rates in co-users
Whether the method of cannabis use (smoking vs. edibles) matters for tobacco cessation outcomes

Common questions

Why might cannabis make it harder to quit smoking?

Several mechanisms are possible: shared smoking behavior reinforces the hand-to-mouth habit, cannabis and tobacco are often used together (blunts, spliffs), both activate reward pathways, and cannabis may reduce the perceived urgency of quitting smoking.

Should tobacco cessation programs screen for cannabis use?

This study suggests yes. Over one-third of smokers also used cannabis, and co-users had significantly lower quit rates. Addressing both substances together, rather than treating them separately, may improve cessation outcomes.

Read the original research

Cannabis Use and Subsequent Cigarette Discontinuation Among U.S. Adults in the Population Assessment of Tobacco and Health Study, Waves 1-5.

Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco, 27(2), 208-216

View on PubMed ↗Publisher’s paper ↗

Citation

Sedani, Ami E; Frank-Pearce, Summer G; Beebe, Laura A; Campbell, Janis E; Peck, Jennifer D; Chou, Ann F; Cohn, Amy M. (2025). Cannabis Use and Subsequent Cigarette Discontinuation Among U.S. Adults in the Population Assessment of Tobacco and Health Study, Waves 1-5.. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco, 27(2), 208-216. https://doi.org/10.1093/ntr/ntae202