While overall cannabis-related treatment admissions dropped from 18.7% to 8.9% between 2010-2021, recreational cannabis legalization was associated with increased treatment-seeking starting four years after implementation.
substance abuse treatment providers, public health policymakers, health equity researchers
What the researchers found
Cannabis-related treatment admissions decreased from 18.7% of all substance treatment admissions in 2010 to 8.9% in 2021. Recreational cannabis law showed no immediate effect on treatment admissions, but a delayed increase beginning in the fourth year after implementation. The impact was particularly large among racial and ethnic minority populations.
Why it matters
The delayed effect suggests legalization may initially normalize cannabis use (reducing treatment-seeking) before eventually bringing more people into treatment as problematic use patterns develop. The disproportionate impact on minority populations raises equity concerns.
The numbers in context
Cannabis treatment admissions: 18.7% (2010) to 8.9% (2021). 19,873,143 unweighted admissions. 54.7% aged 21-39. 65.8% male. Delayed effect beginning year 4 post-legalization. Significant impact on racial/ethnic minority populations.
How the study worked
Analysis of Treatment Episode Data Set-Admissions (2010-2021) covering all substance use treatment admissions. Difference-in-differences models comparing states with and without recreational cannabis laws. Stratified by age, sex, and race/ethnicity.
What this study cannot tell us
Treatment admissions reflect both cannabis use patterns and treatment-seeking behavior, which are influenced by legal status and stigma. Cannot separate actual need from willingness to seek treatment. TEDS data may not capture all treatment settings.
How to read the evidence
Large national dataset with difference-in-differences design provides moderate causal evidence, but treatment admissions reflect both need and willingness to seek help.
When this study was published
2025 publication with 2010-2021 data.
The bigger picture
The overall decline in cannabis treatment admissions may reflect changing attitudes rather than reduced problematic use. The delayed post-legalization increase suggests that as legal cannabis markets mature, more people develop use patterns requiring treatment.
Questions still open
- Is the delayed increase driven by more problematic use or reduced stigma around seeking help?
- Why are minority populations disproportionately affected?
Common questions
Does legalization lead to more people needing cannabis treatment?
Does cannabis legalization affect all groups equally?
Read the original research
The Association Between Recreational Cannabis Legalization and Substance Use Treatment Admissions for Cannabis Misuse, 2010-2021.
American journal of preventive medicine, 70(4), 108186
Citation
Sun, Ruoyan; Zhang, Hao. (2025). The Association Between Recreational Cannabis Legalization and Substance Use Treatment Admissions for Cannabis Misuse, 2010-2021.. American journal of preventive medicine, 70(4), 108186. https://doi.org/10.1016/j.amepre.2025.108186