As legalization of cannabis has expanded in many states over the past few years, cannabis use has increased especially within college-age adults. Cannabis use is often perceived as harmless; however, it can lead to a variety of negative effects including impaired academic performance and neurocognitive damage. Regular cannabis use is known to affect dopamine regulation within the mesolimbic region of the brain, which is known to play a role in effort-related decision making. This finding has led some to believe that cannabis use results in a lack of motivation. This study examines associations between cannabis use and effort-related decision making in college students.
The study’s sample consisted of 25 cannabis-using and 22 noncannabis-using students from a large public university in the United States. Students were asked to report the number of days that they used cannabis and alcohol within the past month. Participants were also screened for Cannabis Use Disorder using DSM-5 criteria. Effort-related decision making was measured using the Effort Expenditure for Rewards Task (EEfRT) which required participants to push a button a certain number of times during a designated time period after selecting an effort level to win a reward. Distress tolerance and delay discounting were also assessed using questionnaires. Data was analyzed using Generalized Estimating Equations (GEE) to examine variables that were correlated with likelihood of the participant making a high-effort decision.
Results of the data analysis showed cannabis users completed fewer EEfRT trials compared to non-users. Non-users chose to complete more low-effort trials and completed more of the low-effort trials successfully compared to cannabis users . There was not a statistically significant difference in the number of high-effort trials selected and the ability to complete the high-effort trials successfully between the two groups. However, as the number of reported cannabis use days increased, there was a greater likelihood of the participant selecting a high-effort trial. This association, however, was not statistically significant.
Takeaway: Cannabis use may not be associated with lack of motivation and effort-related decision making in college students.