Fervaha Gagan, Agid Ofer, Foussias George, Siddiqui Ishraq, Takeuchi Hiroyoshi, Remington Gary
Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Room 320, Toronto, ON, M5T 1R8, Canada.
Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
Eur Arch Psychiatry Clin Neurosci. 2016 Aug;266(5):397-407. doi: 10.1007/s00406-015-0629-6. Epub 2015 Aug 11.
Schizophrenia is a heterogeneous disorder characterized by numerous diverse signs and symptoms. Individuals with prominent, persistent, and idiopathic negative symptoms are thought to encompass a distinct subtype of schizophrenia. Previous work, including studies involving neuropsychological evaluations, has supported this position. The present study sought to further examine whether deficit patients are cognitively distinct from non-deficit patients with schizophrenia. A comprehensive neurocognitive battery including tests of verbal memory, vigilance, processing speed, reasoning, and working memory was administered to 657 patients with schizophrenia. Of these, 144 (22 %) patients were classified as deficit patients using a proxy identification method based on severity, persistence over time, and possible secondary sources (e.g., depression) of negative symptoms. Deficit patients with schizophrenia performed worse on all tests of cognition relative to non-deficit patients. These patients were characterized by a generalized cognitive impairment on the order of about 0.4 standard deviations below that of non-deficit patients. However, when comparing deficit patients to non-deficit patients who also present with negative symptoms, albeit not enduring or primary, no group differences in cognitive performance were found. Furthermore, a discriminant function analysis classifying patients into deficit/non-deficit groups based on cognitive scores demonstrated only 62.3 % accuracy, meaning over one-third of individuals were misclassified. The deficit subtype of schizophrenia is not markedly distinct from non-deficit schizophrenia in terms of neurocognitive performance. While deficit patients tend to have poorer performance on cognitive tests, the magnitude of this effect is relatively modest, translating to over 70 % overlap in scores between groups.
精神分裂症是一种异质性疾病，其特征是有众多不同的体征和症状。具有显著、持续且特发性阴性症状的个体被认为包含精神分裂症的一种独特亚型。先前的研究工作，包括涉及神经心理学评估的研究，都支持这一观点。本研究旨在进一步考察缺陷型患者在认知方面是否与非缺陷型精神分裂症患者不同。对657名精神分裂症患者进行了一套全面的神经认知测试，包括言语记忆、警觉性、处理速度、推理和工作记忆测试。其中，144名（22%）患者使用基于阴性症状的严重程度、随时间的持续性以及可能的继发来源（如抑郁症）的替代识别方法被归类为缺陷型患者。与非缺陷型患者相比，缺陷型精神分裂症患者在所有认知测试中的表现都更差。这些患者的特征是普遍存在认知障碍，程度比非缺陷型患者低约0.4个标准差。然而，当将缺陷型患者与同样有阴性症状但并非持久或原发性阴性症状的非缺陷型患者进行比较时，未发现认知表现上的组间差异。此外，基于认知分数将患者分为缺陷型/非缺陷型组的判别函数分析显示准确率仅为62.3%，这意味着超过三分之一的个体被错误分类。就神经认知表现而言，精神分裂症的缺陷型亚型与非缺陷型精神分裂症并无明显差异。虽然缺陷型患者在认知测试中的表现往往较差，但这种影响的程度相对较小，两组之间的分数重叠率超过70%。
