Background Cannabis use has increased in recent years. However, the long-term implications of cannabis use on brain health remain unknown. We explored the associations of cannabis use with volumetric brain magnetic resonance imaging (MRI) measures in dementia-free older adults. Methods This cross-sectional and longitudinal study included dementia-free participants of the UK Biobank aged ≥60 years. Linear regression models were used to evaluate the association of cannabis use and patterns of use with volumetric brain MRI measures. The association between cannabis use and change in brain MRI measures over time was also tested. All models were adjusted for potential confounders. Results The sample included 19,932 participants (mean age 68 ± 5 years, 48% men), 3,800 (19%) reported lifetime use of cannabis. Cannabis use was associated with smaller total, white, grey and peripheral cortical grey matter volumes (B = −6,690 ± 1,157; P < 0.001, B = −4,396 ± 766; P < 0.001, B = −2,140 ± 690; P = 0.002 and B = −2,451 ± 606; P < 0.001, respectively). Among cannabis users, longer duration of use was associated with smaller total brain, grey and cortical grey matter volumes (B = −7,878 ± 2,396; P = 0.001, B = −5,411 ± 1,430; P < 0.001, B = −5,396 ± 1,254; P < 0.001, respectively), and with increased white matter hyperintensity volume (B = 0.09 ± 0.03; P = 0.008). Additionally, current vs. former users (B = −10,432 ± 4,395; P = 0.020) and frequent versus non-frequent users (B = −2,274 ± 1,125; P = 0.043) had smaller grey and cortical grey matter volumes, respectively. No significant associations were observed between cannabis use and change in brain MRI measures. Discussion Our findings suggest that cannabis use, particularly longer duration and frequent use, may be related to smaller grey and white matter volumes in older ages, but not to late-life changes in these measures over time.

中文翻译：

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老年人大麻使用与神经影像学测量之间的关联：英国生物银行的发现

背景 近年来大麻的使用有所增加。然而，使用大麻对大脑健康的长期影响仍然未知。我们探讨了无痴呆老年人吸食大麻与体积脑磁共振成像 (MRI) 测量之间的关系。方法 这项横断面和纵向研究纳入了英国生物银行年龄≥60 岁的无痴呆参与者。线性回归模型用于评估大麻使用和使用模式与体积脑 MRI 测量的关联。还测试了大麻使用与大脑 MRI 测量值随时间变化之间的关联。所有模型都针对潜在的混杂因素进行了调整。结果 样本包括 19,932 名参与者（平均年龄 68 ± 5 岁，48% 为男性），其中 3,800 名参与者（19%）报告终生使用大麻。大麻的使用与较小的白色、灰色和外周皮质灰质体积有关（B = -6,690 ± 1,157；P < 0.001，B = -4,396 ± 766；P < 0.001，B = -2,140 ± 690；P分别 = 0.002 和 B = -2,451 ± 606；P ＜ 0.001）。在大麻使用者中，使用时间较长与大脑、灰质和皮质灰质体积较小有关（B = -7,878 ± 2,396；P = 0.001，B = -5,411 ± 1,430；P < 0.001，B = -5,396 ± 1,254；P < 0.001，分别），并且白质高信号体积增加（B = 0.09 ± 0.03；P = 0.008）。此外，当前用户与前用户（B = −10,432 ± 4,395；P = 0.020）以及频繁用户与非频繁用户（B = −2,274 ± 1,125；P = 0.043）的灰质和皮质灰质体积分别较小。大麻使用与脑部 MRI 测量值变化之间没有观察到显着关联。讨论我们的研究结果表明，大麻的使用，特别是较长的持续时间和频繁的使用，可能与老年人灰质和白质体积较小有关，但与晚年这些指标随时间的变化无关。