Zhang Xueyi, Chen Zhengju, Becker Benjamin, Shan Tong, Chen Taolin, Gong Qiyong
Department of Radiology and Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China; Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, Sichuan, China; College of Medical Technology, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
Department of Radiology and Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
Prog Neuropsychopharmacol Biol Psychiatry. 2025 Jan 10;136:111156. doi: 10.1016/j.pnpbp.2024.111156. Epub 2024 Sep 29.
Differences in the volumes of the hippocampus and amygdala have consistently been observed between young adults with heavy cannabis use relative to their non-using counterparts. However, it remains unclear whether the subfields of these functionally and structurally heterogenous regions exhibit similar patterns of change in young adults with long-term heavy cannabis use disorder (CUD).
This study aims to investigate the effects of long-term heavy cannabis use in young adults on the subregional structures of the hippocampus and amygdala, as well as their longitudinal alterations.
The study sample comprised 20 young adults with heavy cannabis use and 22 matched non-cannabis using healthy volunteers. All participants completed the Cannabis Use Disorder Identification Test (CUDIT) and underwent two T1-structural magnetic resonance imaging (MRI) scans, one at baseline and another at follow-up 3 years later. The amygdala, hippocampus, and their subregions were segmented on T1-weighted anatomical MRI scans, using a previously validated procedure.
At baseline, young adults with heavy CUD exhibited significantly larger volumes in several hippocampal (bilateral presubiculum, subiculum, Cornu Ammonis (CA) regions CA1, CA2-CA3, and right CA4-Dentate Gyrus (DG)) and amygdala (bilateral paralaminar nuclei, right medial nucleus, and right lateral nucleus) subregions compared to healthy controls, but these differences were attenuated at follow-up. Longitudinal analysis revealed an accelerated volumetric decrease in these subregions in young adults with heavy CUD relative to controls. Particularly, compared to healthy controls, significant accelerated volume decreases were observed in the right hippocampal subfields of the parasubiculum, subiculum, and CA4-DG. In the amygdala, similar trends of accelerated volumetric decreases were observed in the left central nucleus, right paralaminar nucleus, right basal nucleus, and right accessory basal nucleus.
The current findings suggest that long-term heavy cannabis use impacts maturational process of the amygdala and hippocampus, especially in subregions with high concentrations of cannabinoid type 1 receptors (CB1Rs) and involvement in adult neurogenesis.
长期大量使用大麻的年轻成年人与不使用大麻的同龄人相比，海马体和杏仁核的体积差异一直存在。然而，对于这些功能和结构上异质性区域的亚区域在长期大量使用大麻导致的使用障碍（CUD）的年轻成年人中是否表现出相似的变化模式，目前尚不清楚。
本研究旨在调查长期大量使用大麻对年轻成年人海马体和杏仁核亚区域结构的影响及其纵向变化。
研究样本包括20名长期大量使用大麻的年轻成年人和22名匹配的不使用大麻的健康志愿者。所有参与者均完成大麻使用障碍识别测试（CUDIT），并接受两次T1结构磁共振成像（MRI）扫描，一次在基线时，另一次在3年后的随访时。使用先前验证的程序，在T1加权解剖MRI扫描上对杏仁核、海马体及其亚区域进行分割。
在基线时，与健康对照组相比，长期大量使用大麻导致CUD的年轻成年人在几个海马体（双侧前下托、下托、海马结构（CA）区域CA1、CA2 - CA3以及右侧CA4 - 齿状回（DG））和杏仁核（双侧旁层核、右侧内侧核和右侧外侧核）亚区域的体积明显更大，但这些差异在随访时减弱。纵向分析显示，与对照组相比，长期大量使用大麻导致CUD的年轻成年人这些亚区域的体积下降加速。特别是，与健康对照组相比，右侧海马体的前下托、下托和CA4 - DG亚区域观察到显著的体积下降加速。在杏仁核中，左侧中央核、右侧旁层核、右侧基底核和右侧副基底核也观察到类似的体积下降加速趋势。
目前的研究结果表明，长期大量使用大麻会影响杏仁核和海马体的成熟过程，特别是在大麻素1型受体（CB1Rs）浓度高且参与成人神经发生的亚区域。
