Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-25T14:43:34.832Z Has data issue: false hasContentIssue false
  • English
  • Français

Refining the latent structure of neuropsychological performance in schizophrenia

Published online by Cambridge University Press:  22 May 2014

M. Lam ,
S. L. Collinson ,
G. K. Eng ,
A. Rapisarda ,
M. Kraus ,
J. Lee ,
S. A. Chong  and
R. S. E. Keefe
M. Lam
Affiliation:
Research Division, Institute of Mental Health, Singapore
S. L. Collinson
Affiliation:
Department of Psychology, National University of Singapore, Singapore
G. K. Eng
Affiliation:
Research Division, Institute of Mental Health, Singapore Division of Psychology, School of Humanities and Social Sciences, Nanyang Technological University, Singapore
A. Rapisarda
Affiliation:
Research Division, Institute of Mental Health, Singapore Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore
M. Kraus
Affiliation:
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
J. Lee
Affiliation:
Research Division, Institute of Mental Health, Singapore Department of General Psychiatry 1, Institute of Mental Health, Singapore Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore
S. A. Chong
Affiliation:
Research Division, Institute of Mental Health, Singapore
R. S. E. Keefe*
Affiliation:
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
*
*Address for correspondence: R. S. E. Keefe, Ph.D., Department of Psychiatry, Box 3270, Duke University Medical Center, Durham, NC 27710, USA. (Email: Richard.keefe@duke.edu)
Get access Rights & Permissions [Opens in a new window]

Abstract

Background.

Elucidating the cognitive architecture of schizophrenia promises to advance understanding of the clinical and biological substrates of the illness. Traditional cross-sectional neuropsychological approaches differentiate impaired from normal cognitive abilities but are limited in their ability to determine latent substructure. The current study examined the latent architecture of abnormal cognition in schizophrenia via a systematic approach.

Method.

Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were carried out on a large neuropsychological dataset including the Brief Assessment of Cognition in Schizophrenia, Continuous Performance Test, Wisconsin Card Sorting Test, Benton Judgment of Line Orientation Test, and Wechsler Abbreviated Scale of Intelligence matrix reasoning derived from 1012 English-speaking ethnic Chinese healthy controls and 707 schizophrenia cases recruited from in- and out-patient clinics.

Results.

An initial six-factor model fit cognitive data in healthy and schizophrenia subjects. Further modeling, which accounted for methodological variance between tests, resulted in a three-factor model of executive functioning, vigilance/speed of processing and memory that appeared to best discriminate schizophrenia cases from controls. Factor analytic-derived g estimands and conventionally calculated g showed similar case–control discrimination. However, agreement analysis suggested systematic differences between both g indices.

Conclusions.

Factor structures derived in the current study were broadly similar to those reported previously. However, factor structures between schizophrenia subjects and healthy controls were different. Roles of factor analytic-derived g estimands and conventional composite score g were further discussed. Cognitive structures underlying cognitive deficits in schizophrenia may prove useful for interrogating biological substrates and enriching effect sizes for subsequent work.

Keywords

Bland–Altman analysisconfirmatory factor analysisendophenotypesexploratory factor analysisg
Type
Original Articles
Information
Psychological Medicine , Volume 44 , Issue 16 , December 2014 , pp. 3557 - 3570
Copyright
Copyright © Cambridge University Press 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Albright, JJ, Hun, MP (2009). Confirmatory Factor Analysis Using Amos, LISREL, Mplus, and SAS/STAT CALIS. Working Paper. The University Information Technology Services (UITS) Center for Statistical and Mathematical Computing, Indiana University (http://www.indiana.edu/~statmath/stat/all/cfa/index.html). Accessed 27 December 2012.Google Scholar
Aleman, A, Hijman, R, de Haan, EHF, Kahn, RS (1999). Memory impairment in schizophrenia: a meta-analysis. American Journal of Psychiatry 156, 1358–1366.Google Scholar
Appels, M, Sitskoorn, MM, Westers, P, Lems, E, Kahn, RS (2003). Cognitive dysfunctions in parents of schizophrenic patients parallel the deficits found in patients. Schizophrenia Research 63, 285–293.Google Scholar
Bentler, PM (1990). Comparative fit indexes in structural models. Psychological Bulletin 107, 238–246.Google Scholar
Bentler, PM, Bonett, DG (1980). Significance tests and goodness of fit in the analysis of covariance structures. Psychological Bulletin 88, 588–606.Google Scholar
Benton, AL, Sivan, AB, Hamsher, K, Varney, NR, Spreen, O (1994). Contributions to Neuropsychological Assessment: A Clinical Manual. Oxford University Press: Oxford.Google Scholar
Birkett, P, Sigmundsson, T, Sharma, T, Toulopoulou, T, Griffiths, TD, Reveley, A, Murray, R (2008). Executive function and genetic predisposition to schizophrenia – the Maudsley Family Study. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics 147, 285–293.CrossRefGoogle ScholarPubMed
Bland, MJ, Altman, D (1986). Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 327, 307–310.Google Scholar
Blom, G (1958). Statistical Estimates and Transformed Beta-Variables. Wiley: Stockholm.Google Scholar
Bokat, CE, Goldberg, TE (2003). Letter and category fluency in schizophrenic patients: a meta-analysis. Schizophrenia Research 64, 73–78.Google Scholar
Bollen, KA (1986). Sample size and Bentler and Bonett's nonnormed fit index. Psychometrika 51, 375–377.Google Scholar
Bollen, KA (1989). A new incremental fit index for general structural equation models. Sociological Methods and Research 17, 303–316.Google Scholar
Bowie, CR, Leung, WW, Reichenberg, A, McClure, MM, Patterson, TL, Heaton, RK, Harvey, PD (2008). Predicting schizophrenia patients’ real-world behavior with specific neuropsychological and functional capacity measures. Biological Psychiatry 63, 505–511.CrossRefGoogle ScholarPubMed
Brekke, JS, Hoe, M, Long, J, Green, MF (2007). How neurocognition and social cognition influence functional change during community-based psychosocial rehabilitation for individuals with schizophrenia. Schizophrenia Bulletin 33, 1247–1256.Google Scholar
Breton, F, Planté, A, Legauffre, C, Morel, N, Adès, J, Gorwood, P, Ramoz, N, Dubertret, C (2011). The executive control of attention differentiates patients with schizophrenia, their first-degree relatives and healthy controls. Neuropsychologia 49, 203–208.CrossRefGoogle ScholarPubMed
Browne, MW, Cudeck, R (1993). Alternative ways of assessing model fit. In Testing Structural Models (ed. Bollen, K. A. and Long, J. S.), pp. 136–162. Sage Publications: Newbury Park, CA.Google Scholar
Cannon, TD, Keller, MC (2006). Endophenotypes in the genetic analyses of mental disorders. Annual Review of Clinical Psychology 2, 267–290.CrossRefGoogle ScholarPubMed
Carroll, JB (1993). Human Cognitive Abilities: A Survey of Factor-Analytic Studies. Cambridge University Press.Google Scholar
Collinson, SL, Lam, M, Hayes, CJ (2010). The utility and benefits of clinical neuropsychology in Asia. Asian Journal of Psychiatry 3, 50–54.Google Scholar
Cornblatt, BA, Risch, NJ, Faris, G, Friedman, D, Erlenmeyer-Kimling, L (1988). The Continuous Performance Test, identical pairs version (CPT-IP): I. New findings about sustained attention in normal families. Psychiatry Research 26, 223–238.Google Scholar
Daban, C, Amado, I, Bourdel, M-C, Loo, H, Olié, J-P, Poirier, M-F, Krebs, M-O (2005). Cognitive dysfunctions in medicated and unmedicated patients with recent-onset schizophrenia. Journal of Psychiatric Research 39, 391–398.Google Scholar
Davies, G, Tenesa, A, Payton, A, Yang, J, Harris, SE, Liewald, D, Ke, X, Le Hellard, S, Christoforou, A, Luciano, M, McGhee, K, Lopez, L, Gow, AJ, Corley, J, Redmond, P, Fox, HC, Haggarty, P, Whalley, LJ, McNeill, G, Goddard, ME, Espeseth, T, Lundervold, AJ, Reinvang, I, Pickles, A, Steen, VM, Ollier, W, Porteous, DJ, Horan, M, Starr, JM, Pendleton, N, Visscher, PM, Deary, IJ (2011). Genome-wide association studies establish that human intelligence is highly heritable and polygenic. Molecular Psychiatry 16, 996–1005.Google Scholar
Deary, IJ (2012). Intelligence. Annual Review of Psychology 63, 453–482.Google Scholar
Dickinson, D, Gold, JM (2008). Less unique variance than meets the eye: overlap among traditional neuropsychological dimensions in schizophrenia. Schizophrenia Bulletin 34, 423–434.Google Scholar
Dickinson, D, Harvey, PD (2009). Systemic hypotheses for generalized cognitive deficits in schizophrenia: a new take on an old problem. Schizophrenia Bulletin 35, 403–414.Google Scholar
Dickinson, D, Ragland, JD, Calkins, ME, Gold, JM, Gur, RC (2006). A comparison of cognitive structure in schizophrenia patients and healthy controls using confirmatory factor analysis. Schizophrenia Research 85, 20–29.Google Scholar
Dickinson, D, Ramsey, ME, Gold, JM (2007). Overlooking the obvious: a meta-analytic comparison of digit symbol coding tasks and other cognitive measures in schizophrenia. Archives of General Psychiatry 64, 532–542.Google Scholar
Dickinson, D, Schaefer, J, Weinberger, DR (2013). The multi-faceted, ‘global’ cognitive impairment profile in schizophrenia. In Cognitive Impairment in Schizophrenia (ed. Harvey, P. D.). Cambridge University Press.Google Scholar
DiStefano, C, Min, Z, Mîndrilă, D (2009). Understanding and using factor scores: considerations for the applied researcher. Practical Assessment, Research & Evaluation 41, 1–11.Google Scholar
Donohoe, G, Deary, IJ, Glahn, DC, Malhotra, AK, Burdick, KE (2013). Neurocognitive phenomics: examining the genetic basis of cognitive abilities. Psychological Medicine 43, 2027–2036.Google Scholar
Egan, MF, Goldberg, TE, Gscheidle, T, Weirich, M, Rawlings, R, Hyde, TM, Bigelow, L, Weinberger, DR (2001). Relative risk for cognitive impairments in siblings of patients with schizophrenia. Biological Psychiatry 50, 98–107.Google Scholar
Fioravanti, M, Carlone, O, Vitale, B, Cinti, M, Clare, L (2005). A meta-analysis of cognitive deficits in adults with a diagnosis of schizophrenia. Neuropsychology Review 15, 73–95.Google Scholar
First, MB, Spitzer, RL, Gibbon, M, Williams, JBW (2002). Structured Clinical Interview for DSM-IV-TR Axis I Disorders, research version, patient edition. Biometrics Research, New York State Psychiatric Institute: New York.Google Scholar
Fisk, AD, Schneider, W (1981). Control and automatic processing during tasks requiring sustained attention: a new approach to vigilance. Human Factors 23, 737–750.CrossRefGoogle Scholar
Genderson, MR, Dickinson, D, Diaz-Asper, CM, Egan, MF, Weinberger, DR, Goldberg, TE (2007). Factor analysis of neurocognitive tests in a large sample of schizophrenic probands, their siblings, and healthy controls. Schizophrenia Research 94, 231–239.CrossRefGoogle Scholar
Gignac, GE (2006). Evaluating subtest ‘g’ saturation levels via the single trait-correlated uniqueness (STCU) SEM approach: evidence in favor of crystallized subtests as the best indicators of ‘g’. Intelligence 34, 29–46.Google Scholar
Gignac, GE (2008). Higher-order models versus direct hierarchical models: g as superordinate or breadth factor? Psychology Science Quarterly 50, 21–43.Google Scholar
Glahn, DC, Almasy, L, Blangero, J, Burk, GM, Estrada, J, Peralta, JM, Meyenberg, N, Castro, MP, Barrett, J, Nicolini, H, Raventós, H, Escamilla, MA (2007). Adjudicating neurocognitive endophenotypes for schizophrenia. American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics 144B, 242–249.Google Scholar
Gottesman, II, Gould, TD (2003). The endophenotype concept in psychiatry: etymology and strategic intentions. American Journal of Psychiatry 160, 636–645.CrossRefGoogle ScholarPubMed
Hair, JF, Anderson, RE (2010). Multivariate Data analysis. Prentice Hall Higher Education.Google Scholar
Harvey, PD, Green, MF, McGurk, SR, Meltzer, HY (2003). Changes in cognitive functioning with risperidone and olanzapine treatment: a large-scale, double-blind, randomized study. Psychopharmacology 169, 404–411.Google Scholar
Harvey, PD, Keefe, RSE (1997). Cognitive impairment in schizophrenia and implications of atypical neuroleptic treatment. CNS Spectrums 2, 201–222.Google Scholar
Harvey, PD, Keefe, RSE, Patterson, TL, Heaton, RK, Bowie, CR (2009). Abbreviated neuropsychological assessment in schizophrenia: prediction of different aspects of outcome. Journal of Clinical and Experimental Neuropsychology 31, 462–471.CrossRefGoogle ScholarPubMed
Harvey, PD, Siu, CO, Romano, S (2004). Randomized, controlled, double-blind, multicenter comparison of the cognitive effects of ziprasidone versus olanzapine in acutely ill inpatients with schizophrenia or schizoaffective disorder. Psychopharmacology 172, 324–332.Google Scholar
Heaton, RK (1993). Wisconsin Card Sorting Test Manual. Psychological Assessment Resources: Odessa, FL.Google Scholar
Heinrichs, RW (2005). The primacy of cognition in schizophrenia. American Psychologist 60, 229–242.Google Scholar
Heinrichs, RW, Zakzanis, KK (1998). Neurocognitive deficit in schizophrenia: a quantitative review of the evidence. Neuropsychology 12, 426–445.Google Scholar
Henry, J, Crawford, J (2005). A meta-analytic review of verbal fluency deficits in schizophrenia relative to other neurocognitive deficits. Cognitive Neuropsychiatry 10, 1–33.Google Scholar
Ho, BC, Alicata, D, Ward, J, Moser, DJ, O'Leary, DS, Arndt, S, Andreasen, NC (2003). Untreated initial psychosis: relation to cognitive deficits and brain morphology in first-episode schizophrenia. American Journal of Psychiatry 160, 142–148.CrossRefGoogle ScholarPubMed
Holdnack, JA, Xiaobin, Zhou, Larrabee, GJ, Millis, SR, Salthouse, TA (2011). Confirmatory factor analysis of the WAIS-IV/WMS-IV. Assessment 18, 178–191.Google Scholar
Hu, M, Chen, J, Li, L, Zheng, Y, Wang, J, Guo, X, Wu, R, Zhao, J (2011). Semantic fluency and executive functions as candidate endophenotypes for the early diagnosis of schizophrenia in Han Chinese. Neuroscience Letters 502, 173–177.Google Scholar
Hunt, E (2011). Human Intelligence. Cambridge University Press: Cambridge.Google Scholar
Jensen, AR (1992). Understanding g in terms of information processing. Educational Psychology Review 4, 271–308.Google Scholar
Jensen, AR (1998). The g Factor: The Science of Mental Ability. Praeger: Westport.Google Scholar
Jensen, AR (2002). Psychometric g: definition and substantiation. In The General Factor of Intelligence: How General Is It? (ed. Sternberg, R. J. and Grigorenko, E. L.), pp. 39–53. Lawrence Erlbaum Associates Publishers: Mahwah.Google Scholar
Johnson, W, Bouchard, TJ Jr, Krueger, RF, McGue, M, Gottesman, II (2004). Just one g: consistent results from three test batteries. Intelligence 32, 95–107.Google Scholar
Johnson, W, te Nijenhuis, J, Bouchard, TJ Jr (2008). Still just 1 g: consistent results from five test batteries. Intelligence 36, 81–95.CrossRefGoogle Scholar
Keefe, RS, Bilder, RM, Harvey, PD, Davis, SM, Palmer, BW, Gold, JM, Meltzer, HY, Green, MF, Miller, DD, Canive, JM, et al. (2006 c). Baseline neurocognitive deficits in the CATIE schizophrenia trial. Neuropsychopharmacology 31, 2033–2046.CrossRefGoogle ScholarPubMed
Keefe, RSE (1995). The contribution of neuropsychology to psychiatry. American Journal of Psychiatry 152, 6–15.Google Scholar
Keefe, RSE, Goldberg, TE, Harvey, PD, Gold, JM, Poe, MP, Coughenour, L (2004). The brief assessment of cognition in schizophrenia: reliability, sensitivity, and comparison with a standard neurocognitive battery. Schizophrenia Research 68, 283–297.Google Scholar
Keefe, RSE, Harvey, PD, Goldberg, TE, Gold, JM, Walker, TM, Kennel, C, Hawkins, K (2008). Norms and standardization of the Brief Assessment of Cognition in Schizophrenia (BACS). Schizophrenia Research 102, 108–115.Google Scholar
Keefe, RSE, Perkins, DO, Gu, H, Zipursky, RB, Christensen, BK, Lieberman, JA (2006 a). A longitudinal study of neurocognitive function in individuals at-risk for psychosis. Schizophrenia Research 88, 26–35.CrossRefGoogle ScholarPubMed
Keefe, RSE, Poe, M, Walker, TM, Harvey, PD (2006 b). The relationship of the Brief Assessment of Cognition in Schizophrenia (BACS) to functional capacity and real-world functional outcome. Journal of Clinical and Experimental Neuropsychology 28, 260.Google Scholar
Kern, RS, Nuechterlein, KH, Green, MF, Baade, LE, Fenton, WS, Gold, JM, Keefe, RSE, Mesholam-Gately, R, Mintz, J, Seidman, LJ, Stover, E, Marder, SR (2008). The MATRICS Consensus Cognitive Battery, part 2: co-norming and standardization. American Journal of Psychiatry 165, 214–220.Google Scholar
Keshavan, MS, Tandon, R, Boutros, NN, Nasrallah, HA (2008). Schizophrenia, ‘just the facts’: what we know in 2008 part 3: neurobiology. Schizophrenia Research 106, 89–107.CrossRefGoogle ScholarPubMed
Knowles, EEM, Weiser, M, David, AS, Dickinson, D, Glahn, D, Gold, J, Davidson, M, Reichenberg, A (2012). Dedifferentiation and substitute strategy: deconstructing the processing-speed impairment in schizophrenia. Schizophrenia Research 142, 129–136.Google Scholar
Kraus, MS, Keefe, RSE (2007). Cognition as an outcome measure in schizophrenia. British Journal of Psychiatry 191, s46–s51.Google Scholar
Kuha, A, Tuulio-Henriksson, A, Eerola, M, Perälä, J, Suvisaari, J, Partonen, T, Lönnqvist, J (2007). Impaired executive performance in healthy siblings of schizophrenia patients in a population-based study. Schizophrenia Research 92, 142–150.Google Scholar
Lam, M, Eng, GK, Rapisarda, A, Subramaniam, M, Kraus, M, Keefe, RSE, Collinson, SL (2012). Formulation of the Age-Education Index: measuring age and education effects in neuropsychological performance. Psychological Assessment.Google Scholar
Lee, J, Park, S (2005). Working memory impairments in schizophrenia: a meta-analysis. Journal of Abnormal Psychology 114, 599–611.CrossRefGoogle ScholarPubMed
Lencz, T, Smith, CW, McLaughlin, D, Auther, A, Nakayama, E, Hovey, L, Cornblatt, BA (2006). Generalized and specific neurocognitive deficits in prodromal schizophrenia. Biological Psychiatry 59, 863–871.Google Scholar
Loo, SK, Shtir, C, Doyle, AE, Mick, E, McGough, JJ, McCracken, J, Biederman, J, Smalley, SL, Cantor, RM, Faraone, SV, Nelson, SF (2012). Genome-wide association study of intelligence: additive effects of novel brain expressed genes. Journal of the American Academy of Child and Adolescent Psychiatry 51, 432–440.e2.CrossRefGoogle ScholarPubMed
MacDonald, AW, Carter, CS (2002). Cognitive experimental approaches to investigating impaired cognition in schizophrenia: a paradigm shift. Journal of Clinical and Experimental Neuropsychology 24, 873–882.Google Scholar
Mackintosh, N (2011). IQ and Human Intelligence. OUP: Oxford.Google Scholar
McLachlan, G, Peel, D (2004). Finite Mixture Models. John Wiley & Sons: New York.Google Scholar
Mesholam-Gately, RI, Giuliano, AJ, Goff, KP, Faraone, SV, Seidman, LJ (2009). Neurocognition in first-episode schizophrenia: a meta-analytic review. Neuropsychology 23, 315–336.Google Scholar
Milev, P, Ho, B-C, Arndt, S, Andreasen, NC (2005). Predictive values of neurocognition and negative symptoms on functional outcome in schizophrenia: a longitudinal first-episode study with 7-year follow-up. American Journal of Psychiatry 162, 495–506.Google Scholar
Niendam, TA, Bearden, CE, Rosso, IM, Sanchez, LE, Hadley, T, Nuechterlein, KH, Cannon, TD (2003). A prospective study of childhood neurocognitive functioning in schizophrenic patients and their siblings. American Journal of Psychiatry 160, 2060–2062.Google Scholar
Nuechterlein, KH, Barch, DM, Gold, JM, Goldberg, TE, Green, MF, Heaton, RK (2004). Identification of separable cognitive factors in schizophrenia. Schizophrenia Research 72, 29–39.Google Scholar
Nuechterlein, KH, Green, MF, Kern, RS, Baade, LE, Barch, DM, Cohen, JD, Essock, S, Fenton, WS, Frese, FJ 3rd, Gold, JM, Goldberg, T, Heaton, RK, Keefe, RSE, Kraemer, H, Mesholam-Gately, R, Seidman, LJ, Stover, E, Weinberger, DR, Young, AS, Zalcman, S, Marder, SR (2008). The MATRICS Consensus Cognitive Battery, part 1: test selection, reliability, and validity. American Journal of Psychiatry 165, 203–213.Google Scholar
Ojeda, N, Pena, J, Sánchez, P, Elizagárate, E, Ezcurra, J (2008). Processing speed mediates the relationship between verbal memory, verbal fluency, and functional outcome in chronic schizophrenia. Schizophrenia Research 101, 225–233.Google Scholar
Ojeda, N, Peña, J, Schretlen, DJ, Sánchez, P, Aretouli, E, Elizagárate, E, Ezcurra, J, Gutiérrez, M (2012). Hierarchical structure of the cognitive processes in schizophrenia: the fundamental role of processing speed. Schizophrenia Research 135, 72–78.Google Scholar
Parasuraman, R, Davies, DR (1977). A taxonomic analysis of vigilance performance. In Vigilance, NATO Conference Series (ed. Mackie, R. R.), pp. 559–574. Springer: New York (http://link.springer.com/chapter/10.1007/978-1-4684-2529-1_26). Accessed 1 June 2013.Google Scholar
Podsakoff, PM, MacKenzie, SB, Lee, J-Y, Podsakoff, NP (2003). Common method biases in behavioral research: a critical review of the literature and recommended remedies. Journal of Applied Psychology 88, 879–903.CrossRefGoogle ScholarPubMed
Prasad, KM, Keshavan, MS (2008). Structural cerebral variations as useful endophenotypes in schizophrenia: do they help construct ‘extended endophenotypes’? Schizophrenia Bulletin 34, 774–790.Google Scholar
Raffard, S, Bayard, S (2012). Understanding the executive functioning heterogeneity in schizophrenia. Brain and Cognition 79, 60–69.CrossRefGoogle ScholarPubMed
Reichenberg, A, Caspi, A, Harrington, H, Houts, R, Keefe, RSE, Murray, RM, Poulton, R, Moffitt, TE (2010). Static and dynamic cognitive deficits in childhood preceding adult schizophrenia: a 30-year study. American Journal of Psychiatry 167, 160–169.Google Scholar
Reichenberg, A, Harvey, PD (2007). Neuropsychological impairments in schizophrenia: integration of performance-based and brain imaging findings. Psychological Bulletin 133, 833–858.Google Scholar
Reilly, JL, Harris, MSH, Khine, TT, Keshavan, MS, Sweeney, JA (2008). Reduced attentional engagement contributes to deficits in prefrontal inhibitory control in schizophrenia. Biological Psychiatry 63, 776–783.Google Scholar
Rodríguez-Sánchez, JM, Crespo-Facorro, B, González-Blanch, C, Perez-Iglesias, R, Vázquez-Barquero, JL (2007). Cognitive dysfunction in first-episode psychosis: the processing speed hypothesis. British Journal of Psychiatry 191, s107–s110.CrossRefGoogle Scholar
Saykin, AJ, Gur, RC, Gur, RE, Mozley, PD, Mozley, LH, Resnick, SM, Kester, DB, Stafiniak, P (1991). Neuropsychological function in schizophrenia: selective impairment in memory and learning. Archives of General Psychiatry 48, 618–624.Google Scholar
Snitz, BE, MacDonald, AW, Carter, CS (2006). Cognitive deficits in unaffected first-degree relatives of schizophrenia patients: a meta-analytic review of putative endophenotypes. Schizophrenia Bulletin 32, 179.CrossRefGoogle ScholarPubMed
Szöke, A, Trandafir, A, Dupont, ME, Méary, A, Schürhoff, F, Leboyer, M (2008). Longitudinal studies of cognition in schizophrenia: meta-analysis. British Journal of Psychiatry 192, 248–257.Google Scholar
Townsend, LA, Malla, AK, Norman, RM (2001). Cognitive functioning in stabilized first-episode psychosis patients. Psychiatry Research 104, 119–131.Google Scholar
Wang, Q, Chan, R, Sun, J, Yao, J, Deng, W, Sun, X, Liu, X, Sham, PC, Ma, X, Meng, H, Murray, RM, Collier, DA, Li, T (2007). Reaction time of the Continuous Performance Test is an endophenotypic marker for schizophrenia: a study of first-episode neuroleptic-naive schizophrenia, their non-psychotic first-degree relatives and healthy population controls. Schizophrenia Research 89, 293–298.Google Scholar
Wang, Q, Vassos, E, Deng, W, Ma, X, Hu, X, Murray, RM, Collier, DA, Li, T (2010). Factor structures of the neurocognitive assessments and familial analysis in first-episode schizophrenia patients, their relatives and controls. Australian and New Zealand Journal of Psychiatry 44, 109–119.Google Scholar
Wechsler, D (1945). Wechsler Memory Scale (http://psycnet.apa.org/psycinfo/1946-00348-000). Accessed 4 December 2012.Google Scholar
Wechsler, D (1955). Manual for the Wechsler Adult Intelligence Scale (http://psycnet.apa.org/psycinfo/1955-07334-000). Accessed 4 December 2012.Google Scholar
Wechsler, D (1999). Wechsler Abbreviated Scale of Intelligence: WASI. Psychological Corp.: San Antonio.Google Scholar
Wilk, CM, Gold, JM, Humber, K, Dickerson, F, Fenton, WS, Buchanan, RW (2004). Brief cognitive assessment in schizophrenia: normative data for the Repeatable Battery for the Assessment of Neuropsychological Status. Schizophrenia Research 70, 175–186.Google Scholar
Supplementary material: File

Lam Supplementary Material

Supplementary Material

Download Lam Supplementary Material(File)
File 694 KB