A commentary exposes how cannabis research is weakened by wildly inconsistent definitions — 'heavy use' ranges from monthly to daily across studies — calling for urgent standardization to enable meaningful evidence synthesis.
Cannabis researchers, policymakers interpreting cannabis evidence, medical professionals, and research methodology specialists.
What the researchers found
Current research methods lack consistency in defining cannabis use variables (e.g., 'occasional' and 'heavy' use vary from monthly to daily). Methods fail to capture form (flower, concentrate, edibles), dose, and cannabinoid content. Self-report biases, inadequate health codes, and inaccurate biological tests all contribute to poor user identification.
Why it matters
If we can't consistently define who a 'cannabis user' is, we can't accurately assess risks, benefits, or outcomes. This undermines every study — from safety to therapeutic potential — and makes it nearly impossible to compare findings across research teams.
The numbers in context
Key inconsistencies: 'heavy use' defined as monthly to daily across studies. Missing variables: form, dose, THC/CBD content, lifetime use patterns. Methods failing: self-report (biased), ICD codes (no general use code), biological tests (inaccurate windows).
How the study worked
Commentary reviewing correlational studies on cannabis outcomes to assess methods for identifying and characterizing users. Compared survey tools, self-report measures, health records, and biochemical assays. Reviewed existing frameworks for cannabis use characterization.
What this study cannot tell us
Commentary, not empirical study. Doesn't provide a fully developed standardized framework (calls for one). Some inconsistency may be inherent to the complexity of cannabis use patterns.
How to read the evidence
Expert commentary identifying a well-documented methodological problem — persuasive but does not itself solve the issue.
When this study was published
Published in 2026, addressing a growing problem as cannabis research volume increases without standardization.
The bigger picture
This is a foundational problem for the entire field of cannabis research. Without solving it, the evidence base for cannabis policy, medical recommendations, and public health guidance will remain unreliable — regardless of how many studies are conducted.
Questions still open
- Can a universal cannabis use taxonomy be developed? Would a standardized survey tool gain international adoption? How can biological testing be improved to reflect actual use patterns?
Common questions
Why can't we trust cannabis research comparisons?
How could this be fixed?
Read the original research
What is a "Cannabis User"?
Clinical therapeutics, 48(1), 22-28
Citation
Fisher, Ruth. (2026). What is a "Cannabis User"?. Clinical therapeutics, 48(1), 22-28. https://doi.org/10.1016/j.clinthera.2025.11.003