After California legalized recreational cannabis, young adults who stayed medical patients used the most, those who became patients increased use, those who left patient status decreased use, and most other drug use declined overall.
Policymakers, researchers, and anyone interested in legalization's effects on cannabis use patterns.
Most other drug use outcomes decreased significantly post-legalization
What the researchers found
Four transition groups emerged: stayed medical patients (MCP), became patients (Into MCP), left patient status (Out of MCP), and non-patient users (NPU). Cannabis days, concentrate use, and driving under influence were highest among MCP, increased for Into MCP, and decreased for Out of MCP. Most other drug use outcomes decreased significantly by wave 4. Self-reported medical use was associated with more frequent cannabis use but less problematic cannabis and other drug use.
Why it matters
Understanding how legalization reshapes medical vs recreational cannabis use patterns helps policymakers evaluate the impact of dual medical-recreational markets.
The numbers in context
64.8% male, 44.1% Hispanic/Latinx. Four transition groups tracked from pre-legalization (wave 1) to post-legalization (wave 4).
How the study worked
Longitudinal cohort of 18-26-year-old cannabis users recruited in Los Angeles in 2014-15 (pre-legalization) and followed to post-legalization. Four waves of data collection examining changes in medical patient status and associated substance use patterns.
What this study cannot tell us
Self-reported data. Los Angeles-specific findings may not generalize. Attrition between waves. Cannot separate legalization effects from maturation effects.
How to read the evidence
Longitudinal cohort with pre/post legalization data, though self-reported and subject to attrition.
When this study was published
Published in 2022 with recruitment in 2014-15.
The bigger picture
The finding that self-reported medical cannabis use was associated with less problematic substance use suggests that medical framing may promote more controlled use patterns.
Questions still open
- Does maintaining medical patient status after recreational legalization reflect more intentional, health-focused cannabis use? How do dual markets affect overall substance use patterns?
Common questions
Did legalization increase problematic cannabis use?
What happened to driving under the influence of cannabis?
Read the original research
Changes in Medical Cannabis Patient Status before and after Cannabis Legalization in California: Associations with Cannabis and Other Drug Use.
Journal of psychoactive drugs, 54(2), 129-139
Citation
Fedorova, Ekaterina V; Ataiants, Janna; Wong, Carolyn F; Iverson, Ellen; Lankenau, Stephen E. (2022). Changes in Medical Cannabis Patient Status before and after Cannabis Legalization in California: Associations with Cannabis and Other Drug Use.. Journal of psychoactive drugs, 54(2), 129-139. https://doi.org/10.1080/02791072.2021.1926604