Rationale: 40 U.S. states have made cannabis medically legal, in 24 of which it is recreationally legal. California was one of the first states to do both. Scientists wanted to know: now that anyone can just walk into a store and buy cannabis, are people still bothering to get a doctor’s recommendation first?

Before recreational cannabis was legal, receiving a doctor’s recommendation was the only way in which it could legally be obtained in California. Once recreational sales started in 2018, anyone 21 and older could buy it without seeing a doctor. Researchers wanted to track whether this shift caused people to stop involving doctors in their cannabis use.

Method: This study used data from the California Health Interview Survey (CHIS). Respondents who reported cannabis use within the past month were also asked if any marijuana use had been encouraged by a healthcare provider. This data set was then subjected to a variety of statistical tests.

Results: Overall cannabis use had limited changes, about 16-17% of people used it each year throughout the entire study period. Meanwhile, doctor-recommended use among cannabis users dropped by more than half, falling from about 1 in 5 users in 2019 to fewer than 1 in 10 by 2024.

Meaning: People didn’t stop using cannabis, they just stopped asking doctors about it. This is worth paying attention to because people with real health conditions may now be choosing products without any medical guidance, which could be risky. As more states legalize recreational cannabis, keeping doctors involved in the conversation becomes more important, not less.