From the Peter Boris Centre for Addictions Research, McMaster University/St. Joseph’s Healthcare Hamilton, Hamilton, Ont., Canada (Petker, Amlung, MacKillop); the Department of Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, Ont., Canada (Petker, Amlung, MacKillop); the Addiction Medicine Service, Homewood Health Centre, Guelph, Ont., Canada (Petker, Owens); the Department of Psychology, University of Georgia, Athens, GA, USA (Sweet, MacKillop); the Michael G. DeGroote Centre for Medicinal Cannabis Research, McMaster University/St. Joseph’s Healthcare Hamilton, Hamilton, Ont., Canada (Amlung, MacKillop); the Department of Human Development and Family Science, University of Georgia, Athens, GA, USA (Oshri); the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, RI, USA (Sweet); and the Homewood Research Institute, Guelph, Ont., Canada (MacKillop).
J Psychiatry Neurosci. 2019 Nov 1;44(6):414-422. doi: 10.1503/jpn.180115.
There is evidence that heavy cannabis use is associated with decrements in cognitive performance, but findings are mixed and studies are often limited by small sample sizes and narrow adjustment for potential confounding variables. In a comparatively large sample, the current study examined associations between multiple indicators of cannabis use in relation to performance on a variety of neuropsychological tasks.
Participants were 1121 adults (54% female) enrolled in the Human Connectome Project. Cannabis involvement comprised recent cannabis use (positive tetrahydrocannabinol screen), total number of lifetime uses, cannabis use disorder and age at first use. The neuropsychological battery comprised performance in episodic memory, fluid intelligence, attention, working memory, executive function, impulsive decision-making, processing speed and psychomotor dexterity. Covariates were age, sex, income, family structure and alcohol and tobacco use.
Positive urinary tetrahydrocannabinol status was associated with worse performance in episodic memory and processing speed, and positive cannabis use disorder status was associated with lower fluid intelligence (all p < 0.005). No other significant associations were present.
The sample was limited to young adults aged 22–36 years. The measures of cannabis involvement were relatively coarse.
Beyond an array of potential confounders, recent cannabis use was associated with deficits in memory and psychomotor performance, and cannabis use disorder was associated with lower overall cognitive functioning in a large normative sample of adults. The findings pertaining to recent use have particular relevance for occupational settings.
有证据表明，大量吸食大麻会导致认知表现下降，但研究结果喜忧参半，而且研究往往受到样本量小和对潜在混杂变量调整范围狭窄的限制。在一个相对较大的样本中，本研究考察了与多种神经认知任务表现相关的多种大麻使用指标之间的关联。
参与者为 1121 名成年人（54%为女性），均参加人类连接组计划。大麻使用情况包括最近大麻使用（四氢大麻酚检测呈阳性）、终生使用次数、大麻使用障碍和首次使用年龄。神经心理学测试包括情景记忆、流体智力、注意力、工作记忆、执行功能、冲动决策、加工速度和心理运动灵活性。协变量包括年龄、性别、收入、家庭结构以及酒精和烟草使用情况。
尿液四氢大麻酚检测呈阳性与情景记忆和加工速度下降有关，大麻使用障碍呈阳性与流体智力下降有关（均 P<0.005）。没有其他显著关联。
样本仅限于年龄在 22-36 岁的年轻人。大麻使用情况的测量指标相对粗糙。
除了一系列潜在的混杂因素外，近期大麻使用与记忆和心理运动表现缺陷有关，大麻使用障碍与成年人大型规范样本的整体认知功能下降有关。与近期使用相关的发现与职业环境特别相关。
