Patterns and correlates of cannabidiol product and marijuana co-use in a sample of U.S. young adults.

Objective: Cannabis-derived products containing cannabidiol with no or minimal levels of delta 9-tetrahydrocannabinol (CBD products) are widely available in the United States and use of these products is common among young adults and those who use marijuana. The purpose of this study was to examine patterns and correlates of CBD product use and co-use with marijuana in a sample of young adults.

Method: The study used cross-sectional survey data collected in 2019-2020 from a cohort of young adults (n = 2534; mean age 23) based primarily in California. The survey assessed lifetime, past-year, and past-month frequency and type of CBD products used, frequency and amount of marijuana consumption and indicators of marijuana use-related problems. Linear, Poisson, and logistic regression models compared individuals reporting past month CBD-only use, marijuana-only use, concurrent CBD + marijuana use (co-use), and use of neither product. Among those reporting co-use, we examined associations between CBD use frequency and marijuana use frequency and heaviness of use (occasions per day) and indicators of problem marijuana use (e.g., Cannabis Use Disorder Identification Test Short-Form, solitary use, marijuana consequences).

Results: Approximately 13% of respondents endorsed past-month CBD use; of these, over three-quarters (79%) indicated past-month co-use of marijuana. Among individuals reporting co-use, more frequent CBD use was associated with more frequent and heavier marijuana use but was not associated with marijuana use-related problems.

Conclusions: CBD use was common and associated with higher levels of marijuana consumption in this sample. Routinely assessing CBD use may provide a more comprehensive understanding of individuals' cannabis product consumption.