Abnormal Structural Nodes of the Reward Network Associated with Impulsive Traits in Cannabis Use Disorder

Cannabis use exerts adverse effects on the brain. However, the structural gray matter change and its relationship with impulsive traits in young adults with cannabis use disorder (CUD) were still unclear.

39 young adults with CUD and 39 matched healthy controls were enrolled from Human Connectome Project Release S1200 dataset in this study. All participants underwent brain structural magnetic resonance imaging scanning following urinalysis screening, then cortical thickness (CT), cortical surface area (CSA), and subcortical gray matter volume (GMV) were calculated for each participant. Independent two sample t-tests were performed to evaluate group differences in these indicators. And Pearson correlation analysis was conducted to evaluate whether brain structural alterations were associated with impulsive traits in CUD.

Young adults with CUD exhibited higher levels of impulsive traits related to controls. Furthermore, CUD revealed lower CT of the right medial orbitofrontal cortex (mOFC), right rostral anterior cingulate cortex (rACC), and left insula, which were involved in the reward network, while there were no significant group differences in CSA. In addition, CUD showed lower GMV of the left caudate compared to controls. Young adults with CUD exhibited significant relationships between impulsive traits and lower CT of right mOFC, CT of right rACC, and GMV of left caudate.

Young adults with CUD revealed abnormal structural alterations within the reward network, which were associated with impulsive traits. These findings shed light on how cannabis use could be associated with the abnormal structural nodes of reward network, which might further impair impulsive trait behavior.