Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Perth, WA, Australia.
Psychol Med. 2010 Oct;40(10):1635-46. doi: 10.1017/S0033291709992078. Epub 2009 Dec 17.
The effects of cannabis use on neuropsychological indices that show characteristic disturbances in schizophrenia are unclear. The effect of cannabis use on these cognitive functions is of particular interest given the hypothesized association between cannabis use and schizophrenia. Therefore, this study aimed to examine the effects of cannabis use on attentional control, working memory and executive functioning, in both healthy individuals and patients with schizophrenia.
Neuropsychological performance was assessed in 36 cannabis users who were otherwise healthy, 35 healthy non-users, 22 cannabis-using patients with schizophrenia, and 49 non-using patients with schizophrenia. Participants were administered the Stroop task, the letter-number sequencing and spatial span subtests of the Wechsler Memory Scale, and the Wisconsin Card Sorting Test (WCST).
Patients with schizophrenia (both cannabis users and non-users) showed significantly poorer performance across all neuropsychological tasks, relative to controls; however, there were no significant differences between schizophrenic cannabis users and schizophrenic non-users on any measures, with the exception of increased non-perseverative errors on the WCST in cannabis-using patients. Similarly, healthy cannabis users showed no significant differences from healthy non-users in any of the cognitive domains, with the exception of a schizophrenic-like increase in perseveration on the WCST.
Amongst both healthy individuals and patients with schizophrenia there appears to be little difference in cognitive performance between cannabis users and non-users, suggesting that cannabis use has only subtle effects on the neurocognitive performance indices assessed here, which have been well established to be disturbed in schizophrenia.
大麻使用对表现出精神分裂症特征性障碍的神经心理学指标的影响尚不清楚。鉴于大麻使用与精神分裂症之间存在假设关联，因此，大麻使用对这些认知功能的影响尤其值得关注。因此，本研究旨在检查大麻使用对健康个体和精神分裂症患者的注意力控制、工作记忆和执行功能的影响。
对 36 名健康的大麻使用者、35 名健康的非使用者、22 名使用大麻的精神分裂症患者和 49 名未使用大麻的精神分裂症患者进行了神经心理学测试。参与者接受了 Stroop 任务、威斯康星卡片分类测试（WCST）和韦氏记忆量表的字母数字排序和空间跨度子测验。
精神分裂症患者（包括大麻使用者和非使用者）在所有神经心理学任务中的表现均明显差于对照组；然而，在任何措施上，精神分裂症大麻使用者和精神分裂症非使用者之间均无显著差异，除了大麻使用患者的 WCST 中非持续错误增加。同样，健康的大麻使用者在任何认知领域均与健康的非使用者无显著差异，除了 WCST 中的坚持性表现出类似精神分裂症的增加。
在健康个体和精神分裂症患者中，大麻使用者和非使用者之间的认知表现似乎差异不大，这表明大麻使用对这里评估的神经认知表现指标仅有细微影响，这些指标在精神分裂症中已经被证明存在障碍。
