Doctor-Recommended Cannabis Use in the Era of Legalization: Trends from California (2019-2024)

California legalized medical cannabis in 1996 and nonmedical adult use in 2016, with commercial recreational sales starting in 2018. The consequences of cannabis legalization and commercialization on medical cannabis utilization are not well understood.

We analyzed data from 178,832 adults (aged ≥18 years) in the California Health Interview Survey (2017-2024). Past-month cannabis use and doctor-recommended use were assessed each year. We fit survey-weighted logistic regression models with year as a categorical predictor, used omnibus Wald tests to assess whether prevalence differed across years, and estimated year-to-year differences with Tukey-adjusted contrasts. All analyses accounted for survey weights, strata, and primary sampling units.

Between 2019 and 2024, about 1.6% of all respondents and 16.4% of past-month cannabis users reported doctor-recommended use. Among past-month users, doctor-recommended use fell from 18.5% (95% Confidence Interval [CI]: 16.6%-20.4%) in 2019 to 8.5% (95% CI: 7.3%-9.8%) in 2024 (p < 0.01). Overall past-month cannabis use held steady, at 16.5% (95% CI: 15.5%-17.6%) in 2019 and 15.4% (95% CI: 14.5%-16.2%) in 2024 (p = 0.22). Tukey-adjusted comparisons showed the decline was most apparent from 2021 onward. The pattern held across sex and most age and racial/ethnic groups, though differences did not reach statistical significance among young adults aged 18-25 (-7.6 percentage points; p = 0.09), Asian respondents (-2.9 percentage points; p = 0.62), or African American respondents (-8.8 percentage points; p = 0.47).

After adult-use legalization and commercialization, doctor-recommended use decreased by more than half among past-month cannabis users, even as overall use remained stable. The decline in doctor-recommended use suggests that legalization and commercialization in California may have altered patterns of medical utilization without reducing population-level use. Together, these findings align with broader national trends in which recreational access may be displacing formal medical oversight. This reduction in physician oversight raises the concern that individuals with complex medical conditions may increasingly rely on the recreational marketplace without the benefit of clinician guidance.