Department of Neurology and Psychiatry, University of Rome Sapienza, Ple A, Moro 5, Rome 00185, Italy.
BMC Psychiatry. 2012 Jun 20;12:64. doi: 10.1186/1471-244X-12-64.
This is an update of a previous meta-analysis published in 2005.
It includes the data published up to march 2010 for a total of 247 papers and 18,300 cases. Cognitive deficits are examined in 5 different domains: Memory functioning (128 studies), Global cognitive functioning (131 studies), Language (70 studies), Executive function (67 studies), Attention (76 studies). Only controlled studies were included: patients vs. normal subjects.
Results evidence that in all domains and in all different analyses performed within each domain, patients show a significant reduction of cognitive efficiency with respect to normal subjects. The between studies heterogeneity is very high in almost all domains. There are various sources of this heterogeneity (age, sex, sample size, type of patients, and type of measurement) which contribute to the high degree of not-overlapping information offered by the single studies.
Our results, based on the current scientific evidence, confirm the previous findings that there is a generalized impairment of various cognitive functions in patients with schizophrenia when compared to normal cases. The modalities with which these results are obtained have not changed over the years and the more recent studies do not modify the high heterogeneity previously found between the studies. This reduces the methodological quality of the results. In order to improve the methodological quality of the studies performed in the field of cognitive deficits of patients with schizophrenia, various factors should be taken into account and better managed in designing future studies.
这是 2005 年发表的先前荟萃分析的更新。
包括截至 2010 年 3 月发表的总共 247 篇论文和 18300 例病例的数据。在 5 个不同领域检查认知缺陷：记忆功能（128 项研究），整体认知功能（131 项研究），语言（70 项研究），执行功能（67 项研究），注意力（76 项研究）。仅包括对照研究：患者与正常受试者。
结果表明，在所有领域以及在每个领域中进行的所有不同分析中，患者的认知效率都明显低于正常受试者。几乎所有领域的研究间异质性都非常高。这种异质性有多种来源（年龄，性别，样本量，患者类型和测量类型），它们导致单个研究提供的信息高度不重叠。
根据当前的科学证据，我们的结果证实了先前的发现，即与正常病例相比，精神分裂症患者存在各种认知功能的普遍损害。多年来，获得这些结果的方式并未改变，并且先前发现的研究之间的高度异质性并未改变。这降低了结果的方法学质量。为了提高精神分裂症患者认知缺陷领域研究的方法学质量，应考虑并在未来研究设计中更好地管理各种因素。
