Cannabis as a shareable commodity in a social discounting task.

Abstract

Cannabis use and cannabis use disorder diagnoses continue to increase in United States college-aged students as more states legalize recreational cannabis. Previous studies have attempted to associate cannabis use with delay discount rates, which involves participants making choices for smaller sooner versus larger later hypothetical rewards. More smaller sooner choices result in higher discount rates and suggest increased impulsivity. Delay discounting studies have shown a significant, but small effect size with people who use cannabis more likely to choose the smaller sooner rewards, relative to people who do not use cannabis. The present study tested whether students with different experience using cannabis (people who currently use cannabis, people who formerly used cannabis, or people who never used cannabis) would be sensitive to sharing a proportion of hypothetical marijuana with another individual at a given social distance, as a putative measure for cannabis value. Results from two separate data sets showed that students classified as current cannabis users were significantly less likely to share a proportion of hypothetical marijuana across a range of social distances, relative to students that self-reported never using cannabis. Students classified as either former or current users were not statistically different. These results were consistent with previous delay discounting results and showed a medium effect size (η 2 ≥ 0.10) for each data set, both separately and when combined. These results indicate that social distance is a meaningful variable that can be used in a modified discounting task to assess differential cannabis value in a student population who are increasingly susceptible to cannabis use disorder. These results may have future clinical implications. Social discount rates for cannabis may be able to differentiate individuals who will continue recreational use versus individuals that may develop cannabis dependence problems. Public Health SignificanceThis study showed that college-aged students who currently use cannabis shared less hypothetical marijuana than students that either stopped using cannabis, or never used cannabis. This result was consistent in two separate student samples and suggests that cannabis value can profitably be assessed with this sharing task for hypothetical marijuana. Replicating this result in a clinical sample may suggest a new diagnostic marker for cannabis use and misuse.