VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
Department of Psychology, Colorado State University, Fort Collins, CO, USA.
Schizophr Res. 2020 Jan;215:300-307. doi: 10.1016/j.schres.2019.10.011. Epub 2019 Nov 16.
Cognitive functioning in schizophrenia is characterized by a generalized impairment in current cognitive ability based on traditional population-based norms. However, these norms assume a normal cognitive trajectory and do not directly account for illness-related declines from expected cognitive potential. Indeed, schizophrenia patients exhibit even greater deviation between their observed and expected cognitive functioning based on expanded norms that leverage premorbid variables resistant to illness-related features. The current study further quantified the extent to which illness-related features account for this deviation from expectation and assessed its relationship to neurophysiologic (mismatch negativity, P3a, theta oscillations), clinical, and psychosocial functioning in schizophrenia patients. Expected cognitive ability (PENN-CNB global cognition) in patients (n = 684) was calculated using healthy comparison subject (n = 660) weighted regression based on premorbid variables resistant to illness-related decline (demographics, single-word reading, parental education). The magnitude of any deviation between current (observed) and regression-predicted (expected) cognitive ability was calculated. Results indicated that 24% (n = 164) of the total patient population exhibited significant (≥-1.96 SD) deviation between observed and expected global cognitive ability. Interestingly, 20% of the total patient population (n = 136) had "normal" range cognitive performance when using traditional population-based norms, but also had significant deviation from expected cognitive ability. The magnitude of this deviation was associated with more severe neurophysiologic abnormalities, longer illness duration, higher levels of negative symptoms, and worse psychosocial functioning. Assessment of cognitive deviation is thus a complementary metric for characterizing the severity of illness-related cognitive declines in patients, while also reflecting the expression and severity of key endophenotypes of schizophrenia.
精神分裂症患者的认知功能表现为基于传统人群基准的当前认知能力普遍受损。然而，这些基准假设了一个正常的认知轨迹，并没有直接考虑到与疾病相关的认知潜力下降。事实上，精神分裂症患者根据利用抗疾病相关特征的前期变量的扩展基准，表现出更大的观察到的认知功能与预期认知功能之间的偏差。本研究进一步量化了与疾病相关的特征对这种预期偏差的程度，并评估了其与精神分裂症患者的神经生理（失匹配负波、P3a、θ 振荡）、临床和心理社会功能的关系。使用基于前期变量抗疾病下降（人口统计学、单个单词阅读、父母教育）的健康对照受试者（n=660）加权回归计算患者（n=684）的预期认知能力（PENN-CNB 总体认知）。计算当前（观察）和回归预测（预期）认知能力之间的任何偏差的程度。结果表明，24%（n=164）的患者群体表现出观察到的和回归预测的总体认知能力之间存在显著（≥-1.96 SD）偏差。有趣的是，20%的患者群体（n=136）在使用传统人群基准时具有“正常”范围的认知表现，但也存在显著的与预期认知能力的偏差。这种偏差的程度与更严重的神经生理异常、更长的疾病持续时间、更高水平的阴性症状和更差的心理社会功能有关。因此，评估认知偏差是一种补充指标，可以描述患者与疾病相关的认知衰退的严重程度，同时也反映了精神分裂症的关键内表型的表达和严重程度。
