School of Public Health, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3498838, Israel.
Age Ageing. 2024 Apr 1;53(4). doi: 10.1093/ageing/afae068.
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.
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.
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.
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.
近年来，大麻的使用有所增加。然而，大麻使用对大脑健康的长期影响仍不清楚。我们探讨了在无痴呆的老年人中，大麻使用与磁共振成像（MRI）测量的脑容量之间的关联。
本横断面和纵向研究纳入了英国生物库中年龄≥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脑 MRI 测量值之间的关联。还测试了大麻使用与随时间变化的脑 MRI 测量值之间的关系。所有模型均经过潜在混杂因素的调整。
样本包括 19932 名参与者（平均年龄 68±5 岁，48%为男性），3800 名（19%）报告有终生大麻使用史。大麻使用与总脑、白质、灰质和外周皮质灰质体积较小有关（B=-6690±1157；P<0.001，B=-4396±766；P<0.001，B=-2140±690；P=0.002，B=-2451±606；P<0.001）。在大麻使用者中，使用时间较长与总脑、灰质和皮质灰质体积较小有关（B=-7878±2396；P=0.001，B=-5411±1430；P<0.001，B=-5396±1254；P<0.001），与白质高信号体积增加有关（B=0.09±0.03；P=0.008）。此外，当前使用者与既往使用者（B=-10432±4395；P=0.020）和频繁使用者与非频繁使用者（B=-2274±1125；P=0.043）的灰质和皮质灰质体积较小。大麻使用与脑 MRI 测量值的变化之间未观察到显著关联。
我们的研究结果表明，大麻使用，特别是使用时间较长和频繁使用，可能与老年人的灰质和白质体积较小有关，但与这些指标在晚年随时间的变化无关。
