Blanchard Jack J, Cohen Alex S
Department of Psychology, University of Maryland, College Park, USA.
Schizophr Bull. 2006 Apr;32(2):238-45. doi: 10.1093/schbul/sbj013. Epub 2005 Oct 27.
This review examines the structural validity of negative symptoms focusing on 2 questions: (1) Do negative symptoms represent a domain separate from other symptoms in schizophrenia? and (2) Within negative symptoms, is there a structure that suggests multidimensionality? Results from exploratory and confirmatory factor analytic studies are examined to address these questions. Across studies and symptom instruments, negative symptoms appear to consistently emerge as a factor separate from other dimensions of the illness in schizophrenia. Whether 2-, 3-, or 5-factor models are identified, negative symptoms consistently load on a factor separate from positive symptoms, affective symptoms of depression or anxiety, and symptoms of disorganization. Focusing on negative symptoms themselves, factor analytic findings suggest that this construct is multidimensional with at least 2 factors (involving diminished expression and anhedonia-asociality). Although these factors were replicable, serious limitations were noted in this literature. Thus, 2- (or even 3- or 5-) factor models of negative symptoms should not be considered definitive, but rather all converge to support the general conclusion of the multidimensionality of negative symptoms. The later findings indicate the importance of employing assessments that provide adequate coverage of the broad domain of negative symptoms. Importantly, caution is noted in the interpretability of findings based on existing instruments, and implications for future assessment are discussed.
本综述聚焦于两个问题,审视阴性症状的结构效度:(1)阴性症状是否代表精神分裂症中与其他症状相分离的一个领域?以及(2)在阴性症状内部,是否存在一种表明多维性的结构?我们对探索性和验证性因素分析研究的结果进行了审视,以回答这些问题。在各项研究和症状量表中,阴性症状似乎始终作为精神分裂症中与该疾病其他维度相分离的一个因素出现。无论识别出的是二因素、三因素还是五因素模型,阴性症状始终载荷于一个与阳性症状、抑郁或焦虑的情感症状以及紊乱症状相分离的因素上。聚焦于阴性症状本身,因素分析结果表明,这一构念具有多维性,至少包含两个因素(涉及表达减少和快感缺失-社交退缩)。尽管这些因素具有可重复性,但该文献中也指出了一些严重的局限性。因此,阴性症状的二因素(甚至三因素或五因素)模型不应被视为定论,而所有这些模型都趋向于支持阴性症状具有多维性这一总体结论。后续研究结果表明,采用能够充分涵盖阴性症状广泛领域的评估方法具有重要意义。重要的是,我们注意到基于现有量表的研究结果在可解释性方面存在问题,并讨论了其对未来评估的启示。