The Neural Correlates of Effort-Based Decision-Making in Cannabis Use Disorder
Approximately 43% of Canadians have used cannabis at least once and approximately 9% of people who use cannabis develop cannabis use disorder (CUD). Cannabis use is linked with amotivational symptoms but no studies have examined the neural correlates of effort-based decision-making in CUD. The purpose of this research was to examine the neural response underlying components of cost-benefit decision-making in CUD and determine if the severity of participants’ CUD was associated with this neural response. In this pilot project, participants with CUD completed many intake assessments, including the Cannabis Use Disorder Identification Test â€“ Revised (CUDIT-R), which was used to determine the severity of their CUD. The participants then completed a modified version of the Effort Expenditure for Rewards Task (EEfRT) during functional magnetic resonance imaging. To examine which brain regions encoded the choice of whether to complete work for a reward, we contrasted the blood oxygen level dependent (BOLD) signal following the first cue versus the second cue on the EEfRT. This contrast was correlated with the CUDIT-R scores to explore relationships with CUD severity. We expect that there will be increased BOLD activity in several brain regions, including the ventral striatum, anterior insula and dorsal anterior cingulate cortex, following presentation of both cues. As well, we expect BOLD activity in these areas to be inversely related to CUDIT-R scores. This research will elucidate the effects of chronic cannabis use on effort-based decision-making in the brain, which can be utilized in developing targeted CUD treatments focusing on improving motivation.