Dose-related Neurocognitive Effects of Marijuana Use

背景技术背景：尽管美国人口中约有700万人每周至少使用大麻，但关于大麻使用的持续神经认知影响的科学数据很少。目的：确定在28天禁欲的重度大麻使用者中神经认知缺陷是否持续存在，以及这些缺陷是否与每周吸食大麻的数量有关。方法：对28天的重度大麻滥用者进行了一系列神经认知测试。研究结果：随着每周吸烟量的增加，在测量记忆力、执行功能、心理速度和手的灵活性的测试中，表现会下降。当将该组分为轻度、中度和重度用户组时，重度用户组在35项测量中的5项上的表现显著低于轻度用户组，效应大小范围为3.00至4.20 SD单位。使用时间对神经认知性能的影响很小。结论：大量使用大麻与神经认知能力的持续下降有关，即使在戒断28天后也是如此。目前还不清楚这些递减是否会随着持续的禁欲而解决，或者随着持续大量使用大麻而逐渐恶化。

BACKGROUND: Although about 7 million people in the US population use marijuana at least weekly, there is a paucity of scientific data on persistent neurocognitive effects of marijuana use. OBJECTIVE: To determine if neurocognitive deficits persist in 28-day abstinent heavy marijuana users and if these deficits are dose-related to the number of marijuana joints smoked per week. METHODS: A battery of neurocognitive tests was given to 28-day abstinent heavy marijuana abusers. RESULTS: As joints smoked per week increased, performance decreased on tests measuring memory, executive functioning, psychomotor speed, and manual dexterity. When dividing the group into light, middle, and heavy user groups, the heavy group performed significantly below the light group on 5 of 35 measures and the size of the effect ranged from 3.00 to 4.20 SD units. Duration of use had little effect on neurocognitive performance. CONCLUSIONS: Very heavy use of marijuana is associated with persistent decrements in neurocognitive performance even after 28 days of abstinence. It is unclear if these decrements will resolve with continued abstinence or become progressively worse with continued heavy marijuana use.