Changes in Sources of Information about the Risks and Benefits of Cannabis in a National Cohort of US Adults from 2017 - 2021.

Objective: As more states legalize cannabis in the US, marketing from the cannabis industry and news coverage of cannabis have increased. Sources of information on cannabis can influence beliefs about risks and benefits. Yet, little is known about how the use and influence of specific sources of information have changed over time.

Method: We conducted a longitudinal study of 5053 US adults between 2017 and 2021. Participants were asked about sources of information on cannabis risks and benefits and which sources were most influential using a web-based survey at three different time points (2017, 2020, 2021). We evaluated changes in the use/influence of multiple sources of information from 2017 to 2021 and examined interactions with age, cannabis use and state cannabis legal status.

Results: The largest increases in sources of information on cannabis benefits and risks were in use of health professionals (+5.5% for benefits and +17.4% for risks). The largest declines were in use of traditional media (TV, radio, newspapers) (-12.3% and -11.4%). Use of cannabis advertisements and dispensaries/other industry sources also significantly increased. Health professionals were the most influential source of information in all three waves regardless of age, cannabis use or state legal status.

Conclusions: Participants sought information from different sources, and increasingly relied on health professionals as a primary source, highlighting the need to train healthcare providers about cannabis risks and benefits. While fewer people used traditional media, use of industry sources increased, underscoring the need for accurate cannabis information sources.