A similar trend was observed for the measure of past-month marijuana use, which is indicative of heavier use. Only 5.1% of those who never saw advertisements for marijuana on billboards used marijuana in the past month, compared to 35.6% of those who saw them more than once a day.
The results for the two associations between seeing advertising for marijuana on billboards and the use of marijuana in the past month and the past year were statistically significant (p < 0.01).
These findings are consistent with those of a study from 2017 that looked at similar variables from earlier versions of the Monitoring the Future survey. This study concluded, “exposure to marijuana advertisements was significantly associated with higher odds of marijuana use among adolescents. Regulations on marijuana advertisements and educational campaigns on harmfulness of illicit marijuana use are needed.”