Chen Chih-Ken, Lin Shih-Ku, Chen Yi-Chih, Huang Ming-Chy, Chen Tzu-Ting, Ree Shao Chun, Wang Liang-Jen
Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan; Chang Gung University School of Medicine, Taoyuan, Taiwan.
Taipei City Hospital and Psychiatric Center, Taipei, Taiwan.
Drug Alcohol Depend. 2015 Mar 1;148:158-64. doi: 10.1016/j.drugalcdep.2014.12.035. Epub 2015 Jan 13.
Prolonged exposure to methamphetamine (meth) has neurotoxic effects and impairs neurocognitive functions. This study aims to ascertain whether meth users who experience persistent psychosis suffer more severe cognitive impairment than those not experiencing persistent psychosis.
This cross-sectional study includes 252 participants: 25 meth users without psychosis (METH-P), 50 with brief psychosis (METH+BP), and 56 with persistent psychosis (METH+PP), as well as 54 patients with schizophrenia and 67 healthy controls. The neurocognitive function and clinical psychopathology of each patient were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS) and the Brief Psychiatric Rating Scale (BPRS), respectively.
All cognitive domains evaluated with BACS (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, executive function, and composite scores) in METH+PP patients were similar to those in the schizophrenia patients and were worse than those in METH-P, METH+BP, and the healthy control subjects. Furthermore, cognitive functioning in meth users that did not experience persistent psychosis showed no statistically significant difference compared with the healthy control subjects. Among the meth users in this study, the negative symptom scores in the BPRS correlated to cognitive performance on the BACS, with the exception of motor speed.
Meth users display heterogeneity in their psychotic symptoms and cognitive profiles. Therefore, persistent psychotic symptoms may denote a risk for cognitive decline among meth users. Further longitudinal studies should be performed in the future to clarify the causal relationship between cognitive deficits and the development of persistent psychosis.
长期接触甲基苯丙胺（冰毒）具有神经毒性作用，并损害神经认知功能。本研究旨在确定经历持续性精神病的冰毒使用者是否比未经历持续性精神病的使用者遭受更严重的认知障碍。
这项横断面研究包括252名参与者：25名无精神病的冰毒使用者（METH-P）、50名有短暂精神病的使用者（METH+BP）和56名有持续性精神病的使用者（METH+PP），以及54名精神分裂症患者和67名健康对照者。分别使用精神分裂症认知简短评估量表（BACS）和简明精神病评定量表（BPRS）对每位患者的神经认知功能和临床精神病理学进行评估。
在METH+PP患者中，用BACS评估的所有认知领域（言语记忆、工作记忆、运动速度、言语流畅性、注意力和处理速度、执行功能及综合评分）与精神分裂症患者相似，且比METH-P、METH+BP患者及健康对照者差。此外，未经历持续性精神病的冰毒使用者的认知功能与健康对照者相比无统计学显著差异。在本研究的冰毒使用者中，BPRS中的阴性症状评分与BACS上的认知表现相关，但运动速度除外。
冰毒使用者在精神病症状和认知特征方面存在异质性。因此，持续性精神病症状可能表明冰毒使用者存在认知衰退风险。未来应进行进一步的纵向研究，以阐明认知缺陷与持续性精神病发展之间的因果关系。
