Department of Psychiatry, University of Cambridge, Cambridge, UK.
Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
J Psychopharmacol. 2021 Nov;35(11):1349-1355. doi: 10.1177/02698811211050548. Epub 2021 Oct 25.
Cannabis is a commonly used recreational drug in young adults. The worldwide prevalence in 18- to 25-year-olds is approximately 35%. Significant differences in cognitive performance have been reported previously for groups of cannabis users. However, the groups are often heterogeneous in terms of cannabis use. Here, we study daily cannabis users with a confirmed diagnosis of cannabis use disorder (CUD) to examine cognitive performance on measures of memory, executive function and risky decision-making.
Forty young adult daily cannabis users with diagnosed CUD and 20 healthy controls matched for sex and premorbid intelligence quotient (IQ) were included. The neuropsychological battery implemented was designed to measure multiple modes of memory (visual, episodic and working memory), risky decision-making and other domains of executive function using subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB).
Our results showed that young adult daily cannabis users with CUD perform significantly poorer on tasks of visual and episodic memory compared with healthy controls. In addition, executive functioning was associated with the age of onset.
Further research is required to determine whether worse performance in cognition results in cannabis use or is a consequence of cannabis use. Chronic heavy cannabis use during a critical period of brain development may have a particularly negative impact on cognition. Research into the persistence of cognitive differences and how they relate to functional outcomes such as academic/career performance is required.
大麻是年轻人中常用的消遣性药物。18 至 25 岁人群中，大麻的全球流行率约为 35%。先前有报道称，大麻使用者群体在认知表现方面存在显著差异。然而，这些群体在大麻使用方面往往存在异质性。在这里，我们研究了经确诊患有大麻使用障碍（CUD）的每日吸食大麻者，以检查他们在记忆、执行功能和冒险决策方面的认知表现。
我们纳入了 40 名患有 CUD 的年轻成年每日吸食大麻者和 20 名性别和先天智商（IQ）匹配的健康对照者。所实施的神经心理学测试组合旨在使用剑桥神经心理学测试自动化电池（CANTAB）中的子测试来衡量多种记忆模式（视觉、情景和工作记忆）、冒险决策和其他执行功能领域。
我们的研究结果表明，患有 CUD 的年轻成年每日吸食大麻者在视觉和情景记忆任务上的表现明显差于健康对照组。此外，执行功能与发病年龄有关。
需要进一步的研究来确定认知表现较差是导致大麻使用的原因还是大麻使用的结果。在大脑发育的关键时期，慢性重度吸食大麻可能对认知产生特别负面的影响。需要研究认知差异的持久性以及它们如何与学术/职业表现等功能结果相关。
