Liang Xinyi, Avram Maria-Mihaela, Gibbs-Dean Toni, Chesney Edward, Oliver Dominic, Wang Simiao, Obreshkova Stiliyana, Spencer Tom, Englund Amir, Diederen Kelly
Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.
School of Medicine, Yale University, New Haven, CT, United States.
Front Psychiatry. 2024 Jul 24;15:1309868. doi: 10.3389/fpsyt.2024.1309868. eCollection 2024.
Cannabis users present an important group for investigating putative mechanisms underlying psychosis, as cannabis-use is associated with an increased risk of psychosis. Recent work suggests that alterations in belief-updating under uncertainty underlie psychosis. We therefore compared belief updating under uncertainty between cannabis and non-cannabis users.
49 regular cannabis users and 52 controls completed the Space Game, via an online platform used for behavioral testing. In the task, participants were asked to predict the location of the stimulus based on previous information, under different uncertainty conditions. Mixed effects models were used to identify significant predictors of mean score, confidence, performance error and learning rate.
Both groups showed decreased confidence in high noise conditions, and increased belief updating in more volatile conditions, suggesting that they could infer the degree and sources of uncertainty. There were no significant effects of group on any of the performance indices. However, within the cannabis group, frequent users showed worse performance than less frequent users.
Belief updating under uncertainty is not affected by cannabis use status but could be impaired in those who use cannabis more frequently. This finding could show a similarity between frequent cannabis use and psychosis risk, as predictors for abnormal belief-updating.
大麻使用者是研究精神病潜在机制的重要群体，因为使用大麻与患精神病风险增加有关。近期研究表明，不确定性下信念更新的改变是精神病的基础。因此，我们比较了大麻使用者和非大麻使用者在不确定性下的信念更新情况。
49名经常使用大麻的使用者和52名对照者通过用于行为测试的在线平台完成了太空游戏。在任务中，参与者被要求在不同的不确定性条件下根据先前信息预测刺激的位置。使用混合效应模型来确定平均得分、信心、表现误差和学习率的显著预测因素。
两组在高噪声条件下信心均降低，在波动性更大的条件下信念更新增加，这表明他们能够推断不确定性的程度和来源。组间对任何表现指标均无显著影响。然而，在大麻使用者组中，频繁使用者的表现比不频繁使用者更差。
不确定性下的信念更新不受大麻使用状态的影响，但在更频繁使用大麻的人群中可能受损。这一发现可能表明频繁使用大麻与精神病风险之间存在相似性，作为异常信念更新的预测因素。
