Mata I, Rodríguez-Sánchez J M, Pelayo-Terán J M, Pérez-Iglesias R, González-Blanch C, Ramírez-Bonilla M, Martínez-García O, Vázquez-Barquero J L, Crespo-Facorro B
University Hospital Marques de Valdecilla, Department of Psychiatry, School of Medicine, University of Cantabria, Santander, Spain.
Psychol Med. 2008 Sep;38(9):1257-66. doi: 10.1017/S0033291707002218. Epub 2007 Nov 16.
Cannabis use appears to be a risk factor for schizophrenia. Moreover, cannabis abusers show impaired decision-making capacities, linked to the orbitofrontal cortex (OFC). Although there is substantial evidence that first-episode schizophrenia patients show impairments in cognitive tasks associated with the dorsolateral prefrontal cortex (DLPFC), it is not clear whether decision making is impaired at schizophrenia onset. In this study, we examined the association between antecedents of cannabis abuse and cognitive impairment in cognitive tasks associated with the DLPFC and the OFC in a sample of first-episode patients with schizophrenia-spectrum disorders.
One hundred and thirty-two patients experiencing their first episode of a schizophrenia-spectrum psychosis were assessed with a cognitive battery including DLPFC-related tasks [backward digits, verbal fluency (FAS) and the Trail Making Test (TMT)] and an OFC-related task [the Iowa Gambling Task (GT)]. Performance on these tasks was compared between patients who had and had not abused cannabis before their psychosis onset.
No differences were observed between the two groups on the performance of any of the DLPFC-related tasks. However, patients who had abused cannabis before their psychosis onset showed a poorer total performance on the gambling task and a lower improvement on the performance of the task compared to no-abusers.
Pre-psychotic cannabis abuse is associated with decision-making impairment, but not working memory and executive function impairment, among first-episode patients with a schizophrenia-spectrum psychosis. Further studies are needed to examine the direction of causality of this impairment; that is, does the impairment make the patients abuse cannabis, or does cannabis abuse cause the impairment?
使用大麻似乎是精神分裂症的一个风险因素。此外，大麻滥用者表现出决策能力受损，这与眶额皮质（OFC）有关。尽管有大量证据表明首发精神分裂症患者在与背外侧前额叶皮质（DLPFC）相关的认知任务中存在损伤，但尚不清楚在精神分裂症发病时决策是否受损。在本研究中，我们在一组首发精神分裂症谱系障碍患者样本中，研究了大麻滥用的 antecedents 与与 DLPFC 和 OFC 相关的认知任务中的认知损伤之间的关联。
对 132 名首次发作精神分裂症谱系精神病的患者进行了认知测试，包括与 DLPFC 相关的任务[倒背数字、言语流畅性（FAS）和连线测验（TMT）]以及与 OFC 相关的任务[爱荷华赌博任务（GT）]。比较了精神病发作前滥用和未滥用大麻的患者在这些任务上的表现。
两组在任何与 DLPFC 相关的任务表现上均未观察到差异。然而，精神病发作前滥用大麻的患者在赌博任务上的总体表现较差且与未滥用者相比任务表现的改善程度较低。
在首发精神分裂症谱系精神病患者中，精神病前大麻滥用与决策损伤有关，但与工作记忆和执行功能损伤无关。需要进一步研究来检查这种损伤的因果关系方向；也就是说，是损伤导致患者滥用大麻还是大麻滥用导致损伤？
