Cannabis use disorder treatment admissions declined in California after legalization | Research

The takeaway

California saw declining cannabis use disorder treatment admissions after adult-use legalization, even as cannabis problems became more prevalent, with racial disparities in who entered and who left treatment.

Cannabis policy researchers, treatment providers, health equity advocates

Treatment declined overall but increased for minorities

What the researchers found

Legalization was associated with decreased CUD treatment admission probability overall (AME -0.005). Decreases were seen for males, Medi-Cal beneficiaries, adults 21+, and Whites. Increases were seen for criminal justice referrals, Black (AME +0.004), and Hispanic (AME +0.009) patients.

Why it matters

If legalization reduces treatment-seeking despite increasing cannabis problems, it could signal normalization of problematic use or reduced stigma-driven referrals. The racial disparities in who enters treatment post-legalization raise equity concerns.

The numbers in context

1,460,066 treatment episodes (2010-2021). Overall AME: -0.005. Males AME: -0.025. Whites AME: -0.012. Criminal justice referrals AME: +0.017. Hispanics AME: +0.009. Blacks AME: +0.004.

How the study worked

Analysis of all publicly funded substance use disorder treatment in California from 2010-2021 (1,460,066 episodes). Individual-level pre-post time series logistic regression with county and year fixed effects.

What this study cannot tell us

Publicly funded treatment only (misses private treatment). Cannot distinguish voluntary from mandated treatment within non-CJ referrals. Pre-post design cannot prove legalization caused changes. Other policy changes may have occurred simultaneously.

How to read the evidence

Large statewide dataset with appropriate time-series methodology, but cannot establish causation and misses private treatment.

When this study was published

2024 analysis of California treatment data from 2010-2021

The bigger picture

The increase in criminal justice referrals for minorities while voluntary treatment seeking declined for others suggests legalization may have differential effects: reducing stigma-based treatment for some while maintaining enforcement-driven treatment for others.

Questions still open

Are people with CUD getting help elsewhere (private treatment, harm reduction)? Does the decline in treatment admissions translate to worse outcomes for people with CUD?

Common questions

Did cannabis legalization reduce people seeking treatment?

Yes overall. CUD treatment admissions declined in California after adult-use legalization, particularly for White adults, males, and Medi-Cal beneficiaries. However, admissions increased for criminal justice referrals and for Black and Hispanic patients.

Why might legalization reduce treatment seeking?

Possible explanations include reduced stigma around cannabis use, normalization of use making problems seem less serious, fewer legal consequences that previously motivated treatment, or people accessing support through non-traditional channels.

Read the original research

Adult use cannabis legalization and cannabis use disorder treatment in California, 2010-2021.

Journal of substance use and addiction treatment, 162, 209345

View on PubMed ↗Publisher’s paper ↗

Citation

Bass, Brittany; Padwa, Howard; Khurana, Dhruv; Urada, Darren; Boustead, Anne. (2024). Adult use cannabis legalization and cannabis use disorder treatment in California, 2010-2021.. Journal of substance use and addiction treatment, 162, 209345. https://doi.org/10.1016/j.josat.2024.209345