Cannabis use has historically been thought to cause amotivation, but the relationship between cannabis and apathy, anhedonia, and reward processing remains poorly characterised. In this systematic review, we evaluated whether cannabis exposure acutely and/or non-acutely was associated with altered reward processing using questionnaire, behavioural, or functional neuroimaging measures. Questionnaire studies demonstrated greater anhedonia in adolescent cannabis users, and some indication of greater apathy in young adult cannabis users. Behavioural studies yielded some evidence of reduced reward learning in adolescent cannabis users, though there were too few studies in this category for reliable conclusions. Finally, longitudinal and acute functional neuroimaging studies showed an association between cannabis and blunted neural responses to reward, which did not emerge consistently in cross-sectional studies. The current results suggest that cannabis use is associated with specific impairments in reward and motivation. Future large-scale, longitudinal studies which use multiple behavioural and neuroimaging measures of reward processing may further clarify the impact of cannabis use on motivational and reward processes, and neural networks.

大麻的使用历来被认为会引起动机，但大麻与冷漠、快感缺乏和奖励处理之间的关系仍然没有得到很好的表征。在本系统评价中，我们使用问卷、行为或功能性神经影像学测量评估了急性和/或非急性接触大麻是否与改变奖励处理有关。问卷研究表明，青少年大麻使用者的快感缺失更严重，而一些迹象表明，年轻的成年大麻使用者更冷漠。行为研究产生了一些证据表明青少年大麻使用者的奖励学习减少，尽管这一类别的研究太少，无法得出可靠的结论。最后，纵向和急性功能性神经影像学研究表明大麻与对奖励的神经反应迟钝之间存在关联，在横断面研究中并未始终如一地出现。目前的结果表明，大麻的使用与奖励和动机的特定损害有关。未来使用奖励处理的多种行为和神经影像学测量的大规模纵向研究可能会进一步阐明大麻使用对激励和奖励过程以及神经网络的影响。