Myran Daniel T, Pugliese Michael, Harrison Lyndsay D, Stall Nathan M, Webber Colleen
Department of Family Medicine, University of Ottawa, Ottawa, Ontario, Canada.
Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
JAMA Neurol. 2025 Apr 14. doi: 10.1001/jamaneurol.2025.0530.
Cannabis use is associated with short-term memory impairment and long-term changes in brain structure; however, little is known about whether disordered cannabis use is associated with an increased risk of a dementia diagnosis.
To investigate the association between emergency department visits or hospitalizations (acute care encounters) due to cannabis and future dementia diagnosis.
DESIGN, SETTING, AND PARTICIPANTS: Population-based, retrospective, matched cohort study using health administrative data from Ontario, Canada, between 2008 and 2021 (with follow-up until 2022) including all individuals aged 45 to 105 years living in Ontario who were eligible and did not have a diagnosis of dementia at cohort entry (2 620 083 individuals excluded).
Individuals with incident acute care due to cannabis use, defined using International Classification of Diseases and Related Health Problems, Tenth Revision coding.
We used cause-specific adjusted hazard models to compare new diagnoses of dementia (from a validated algorithm) between individuals with acute care due to cannabis use with (1) individuals with all-cause acute care (excluding cannabis), (2) the general population, and (3) individuals with acute care due to alcohol use.
The study included 6 086 794 individuals, of whom 16 275 (0.3%) had incident acute care due to cannabis use (mean age, 55.2 [SD, 8.3] years; 60.3% male). Annual rates of incident acute care due to cannabis use increased 5.0-fold in individuals aged 45 to 64 years (from 10.16 to 50.65 per 100 000) and 26.7-fold in individuals aged 65 years or older (from 0.65 to 16.99 per 100 000) between 2008 and 2021. Individuals with incident acute care due to cannabis use were at a 1.5-fold and 3.9-fold increased risk of dementia diagnosis within 5 years relative to individuals with all-cause acute care and the general population of the same age and sex, respectively (absolute rates of dementia diagnosis: 5.0% for cannabis-related acute care, 3.6% for all-cause acute care, and 1.3% in the general population). After adjustment for sociodemographics and chronic health conditions, individuals with acute care due to cannabis use remained at elevated risk relative to those with all-cause acute care (adjusted hazard ratio [aHR], 1.23; 95% CI, 1.09-1.39) and the general population (aHR, 1.72; 95% CI, 1.38-2.15). Individuals with acute care due to cannabis use were at lower risk than those with acute care due to alcohol use (aHR, 0.69; 95% CI, 0.62-0.76).
Individuals with cannabis use severe enough to require hospital-based care were at increased risk of a new dementia diagnosis compared with those with all-cause hospital-based care or the general population. These findings have important implications considering increasing cannabis use among older adults.
大麻使用与短期记忆损害及大脑结构的长期变化有关；然而，对于大麻使用紊乱是否与痴呆症诊断风险增加相关，人们知之甚少。
研究因大麻导致的急诊科就诊或住院（急性护理接触）与未来痴呆症诊断之间的关联。
设计、设置和参与者：基于人群的回顾性匹配队列研究，使用2008年至2021年加拿大安大略省的卫生行政数据（随访至2022年），包括所有居住在安大略省、年龄在45至105岁之间、符合条件且在队列进入时未被诊断为痴呆症的个体（排除2620083人）。
因大麻使用导致急性护理事件的个体，根据《国际疾病分类及相关健康问题，第十次修订版》编码确定。
我们使用特定病因调整风险模型，比较因大麻使用导致急性护理的个体与以下人群的痴呆症新诊断情况（来自经过验证的算法）：（1）因各种病因导致急性护理的个体（不包括大麻）；（2）普通人群；（3）因酒精使用导致急性护理的个体。
该研究纳入6086794人，其中16275人（0.3%）因大麻使用导致急性护理事件（平均年龄55.2[标准差8.3]岁；男性占60.3%）。2008年至2021年期间，45至64岁个体因大麻使用导致急性护理事件的年发生率增加了5.0倍（从每10万人10.16例增至50.65例），65岁及以上个体增加了26.7倍（从每10万人0.65例增至16.99例）。因大麻使用导致急性护理事件的个体在5年内被诊断为痴呆症的风险分别比同年龄和性别的因各种病因导致急性护理的个体及普通人群高1.5倍和3.9倍（痴呆症诊断的绝对发生率：与大麻相关的急性护理为5.0%，各种病因导致的急性护理为3.6%，普通人群为1.3%）。在对社会人口统计学和慢性健康状况进行调整后，因大麻使用导致急性护理的个体相对于因各种病因导致急性护理的个体（调整后风险比[aHR]，1.23；95%置信区间[CI]，1.09 - 1.39）和普通人群（aHR，1.72；95%CI，1.38 - 2.15）仍处于较高风险。因大麻使用导致急性护理的个体比因酒精使用导致急性护理的个体风险更低（aHR，0.69；95%CI，0.62 - 0.76）。
与因各种病因住院治疗的个体或普通人群相比，因大麻使用严重到需要住院护理的个体患新发痴呆症的风险更高。考虑到老年人中大麻使用的增加，这些发现具有重要意义。
