A Longitudinal Investigation of Associations Between Marijuana Displays on Facebook and Self-Reported Behaviors Among College Students.

purposeCollege students frequently display references to substance use, including marijuana, on social media such as Facebook. The significance of displayed marijuana references on social media is unknown. The purpose of this longitudinal cohort study was to evaluate college students' displayed marijuanareferences on Facebook and their association with self-reported marijuana use.

methodsFirst-year students from two U.S. universities were randomly selected from registrar lists for recruitment. Data collection included 4years of monthly Facebook coding, and yearly phone interviews that each assessed lifetime and current marijuana use. We compared frequencies of displayed marijuana references on Facebook between marijuana users and nonusers using two-sample t-tests and Pearson's chi-squared tests. Generalized linear models were used to evaluate the likelihood of displayed marijuana references on Facebook.

resultsA total of 338 participants were recruited, 56.1% were female, 74.8% were Caucasian, and 58.8% were from the Midwest college. Prevalence of displayed marijuana references on Facebook profiles variedfrom 5% to 10% across 4 years. Displayed marijuana references included most "Actions" and "Locations" on the Facebook profile. Marijuana users were more likely to display marijuana references on Facebook compared to nonusers, though Likes were more common among nonusers. Predictors of displayed marijuana references included lifetime and current marijuana use.

conclusionsThe prevalence of displayed marijuana references on Facebook was consistent but uncommon; marijuana references included both information sharing and personal experiences. Marijuana users were more likely to display marijuana references, suggesting these displays could be leveraged for intervention efforts.