School of Psychology, University of Wollongong, Australia.
Psychol Med. 2011 Nov;41(11):2349-59. doi: 10.1017/S003329171100050X. Epub 2011 Apr 5.
The cerebellum is rich in cannabinoid receptors and implicated in the neuropathology of schizophrenia. Long-term cannabis use is associated with functional and structural brain changes similar to those evident in schizophrenia, yet its impact on cerebellar structure has not been determined. We examined cerebellar grey and white matter in cannabis users with and without schizophrenia.
Seventeen patients with schizophrenia and 31 healthy controls were recruited; 48% of the healthy group and 47% of the patients were long-term heavy cannabis users (mean 19.7 and 17.9 years near daily use respectively). Cerebellar measures were extracted from structural 3-T magnetic resonance imaging (MRI) scans using semi-automated methods, and examined using analysis of covariance (ANCOVA) and correlational analyses.
Cerebellar white-matter volume was reduced in cannabis users with and without schizophrenia compared to healthy non-users, by 29.7% and 23.9% respectively, and by 17.7% in patients without cannabis use. Healthy cannabis users did not differ in white-matter volume from either of the schizophrenia groups. There were no group differences in cerebellar grey matter or total volumes. Total cerebellar volume decreased as a function of duration of cannabis use in the healthy users. Psychotic symptoms and illness duration correlated with cerebellar measures differentially between patients with and without cannabis use.
Long-term heavy cannabis use in healthy individuals is associated with smaller cerebellar white-matter volume similar to that observed in schizophrenia. Reduced volumes were even more pronounced in patients with schizophrenia who use cannabis. Cannabis use may alter the course of brain maturational processes associated with schizophrenia.
小脑富含大麻素受体，并与精神分裂症的神经病理学有关。长期使用大麻与大脑功能和结构的变化有关，这些变化与精神分裂症中明显的变化相似，但它对小脑结构的影响尚未确定。我们研究了患有和不患有精神分裂症的大麻使用者的小脑灰质和白质。
招募了 17 名精神分裂症患者和 31 名健康对照者；健康组的 48%和患者组的 47%是长期重度大麻使用者（平均分别为近每日使用 19.7 和 17.9 年）。使用半自动方法从小脑的 3-T 磁共振成像 (MRI) 扫描中提取小脑测量值，并使用协方差分析 (ANCOVA) 和相关分析进行检查。
与健康非使用者相比，患有和不患有精神分裂症的大麻使用者的小脑白质体积均减少，分别减少了 29.7%和 23.9%，而没有大麻使用的患者减少了 17.7%。健康大麻使用者的白质体积与任何一个精神分裂症组都没有差异。小脑灰质或总体积没有组间差异。在健康使用者中，小脑总体积随大麻使用时间的增加而减少。在有和没有大麻使用的患者中，精神病症状和疾病持续时间与小脑测量值的相关性不同。
在健康个体中，长期重度大麻使用与小脑白质体积减少有关，与精神分裂症中观察到的相似。在使用大麻的精神分裂症患者中，体积减少更为明显。大麻使用可能会改变与精神分裂症相关的大脑成熟过程的进程。
