Cognitive deficits in schizophrenia: an updated metanalysis of the scientific evidence

BMC Psychiatry

Maria Elena Cinti¹  Valentina Bianchi¹  Mario Fioravanti¹ 

[1] Department of Neurology and Psychiatry, University of Rome Sapienza, P.le A. Moro 5, Rome, 00185, Italy

关键词: Meta-analysis;    IQ;    Language;    Executive function;    Attention;    Memory;    Cognitive deficits;    Schizophrenia;   

Others  :  1124367
DOI  :  10.1186/1471-244X-12-64

 received in 2011-02-23, accepted in 2012-04-13,  发布年份 2012

【 摘 要 】

Background

This is an update of a previous meta-analysis published in 2005.

Methods

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

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.

Conclusions

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.

【 授权许可】

   
2012 Fioravanti et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Figure 11.

Figure 12.

Figure 13.

Figure 14.

Figure 15.

Figure 16.

【 参考文献 】

• [1]Heinrichs RW, Zakzanis KK: Neurocognitive deficit in schizophrenia, a quantitative review of the evidence. Neuropsychol 1998, 12(Suppl 3):426-445.
• [2]Bilder RM, Lipschutz-Broch L, Reiter G, Geisler S, Mayerhoff D, Lieberman JA: Neuropsychological deficits in the early course of first episode schizophrenia. Schizophr Res 1991, 5:198-199.
• [3]Raji TK, Mulsant BH: Nature and course of cognitive function in late-life schizophrenia: a systematic review. Schizophr Res 2008, 102:122-140.
• [4]Mesholam-Gately RI, Giuliano AJ, Goff KP, Faraone SV, Seidman L: Neurocognition in first-episode schizophrenia: a meta-analytic review. Neuropsychol 2009, 23:315-336.
• [5]Green MF: What are the functional consequences of neurocognitive deficit in schizophrenia? Am J Psych 1996, 153:32-330.
• [6]Kremen WS, Seidman LS, Faraone SV, Toomey R, Lyons MJ, Tsuang MT: Heterogeneity of schizophrenia: a study of individual neuropsychological profiles. Schizophr Res 2004, 71:307-314.
• [7]Fioravanti M, Carlone O, Vitale B, Cinti ME, Clare L: A meta-analysis of cognitive deficits in adults with a diagnosis of schizophrenia. Neuropsychol Rev 2005, 15(Suppl 2):73-95.
• [8]Higgins JPT, Thompson SG: Quantifying heterogeneity in a meta-analysis. Stat Med 2002, 21:1539-1558.
• [9]Egger M: Davey Smith G, Altman DG: Systematic reviews in health care: meta-analysis in context. 2nd edition. London: BMJ Publishing Group; 2001.
• [10]Grissom RJ: Probability of the superior outcome of one treatment over another. J Appl Psychol 1994, 79:314-316.
• [11]Grissom RJ: The Magical Number .7 ± .2: Meta-meta-analysis of the probability of superior outcome in comparisons involving therapy, placebo, and control. J Consult Clin Psychol 1996, 64:973-982.