title: Neuropsychological decline in schizophrenia from the premorbid to the postonset period: evidence from a population-representative longitudinal study.
abstract: OBJECTIVE
  Despite the widespread belief that neuropsychological decline is a cardinal feature of the progression from the premorbid stage to the chronic form of schizophrenia, few longitudinal studies have examined change in neuropsychological functioning from before to after illness onset. The authors examined whether neuropsychological decline is unique to schizophrenia, whether it is generalized or confined to particular mental functions, and whether individuals with schizophrenia also have cognitive problems in everyday life.
  
  
  METHODS
  Participants were members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972 and 1973 and followed prospectively to age 38, with 95% retention. Assessment of IQ and specific neuropsychological functions was conducted at ages 7, 9, 11, and 13, and again at age 38. Informants also reported on any cognitive problems at age 38.
  
  
  RESULTS
  Individuals with schizophrenia exhibited declines in IQ and in a range of mental functions, particularly those tapping processing speed, learning, executive function, and motor function. There was little evidence of decline in verbal abilities or delayed memory, however, and the developmental progression of deficits in schizophrenia differed across mental functions. Processing speed deficits increased gradually from childhood to beyond the early teen years, whereas verbal deficits emerged early but remained static thereafter. Neuropsychological decline was specific to schizophrenia, as no evidence of decline was apparent among individuals with persistent depression, children with mild cognitive impairment, individuals matched on childhood risk factors for schizophrenia, and psychiatrically healthy individuals. Informants also noticed more cognitive problems in individuals with schizophrenia.
  
  
  CONCLUSIONS
  There is substantial neuropsychological decline in schizophrenia from the premorbid to the postonset period, but the extent and developmental progression of decline varies across mental functions. Findings suggest that different pathophysiological mechanisms may underlie deficits in different mental functions.
authors.forename: Madeline H
authors.initials: MH
authors.lastname: Meier
authors.forename: Avshalom
authors.initials: A
authors.lastname: Caspi
authors.forename: Abraham
authors.initials: A
authors.lastname: Reichenberg
authors.forename: Richard S E
authors.initials: RS
authors.lastname: Keefe
authors.forename: Helen L
authors.initials: HL
authors.lastname: Fisher
authors.forename: HonaLee
authors.initials: H
authors.lastname: Harrington
authors.forename: Renate
authors.initials: R
authors.lastname: Houts
authors.forename: Richie
authors.initials: R
authors.lastname: Poulton
authors.forename: Terrie E
authors.initials: TE
authors.lastname: Moffitt
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition; D060825:Cognitive Dysfunction / Q000523:psychology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D009520:New Zealand; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology
references.citation: Biol Psychiatry. 2000 Jul 15;48(2):137-46
references.pmid: 10903410
references.citation: Schizophr Res. 2005 Oct 1;78(1):27-34
references.pmid: 15964177
references.citation: Arch Gen Psychiatry. 2000 Nov;57(11):1053-8
references.pmid: 11074871
references.citation: Psychol Bull. 1995 Mar;117(2):285-305
references.pmid: 7724692
references.citation: J Consult Psychol. 1963 Aug;27:364-66
references.pmid: 14011697
references.citation: J Consult Psychol. 1962 Apr;26:139-43
references.pmid: 14467044
references.citation: Schizophr Res. 2005 Sep 15;77(2-3):271-7
references.pmid: 15913958
references.citation: Am J Psychiatry. 2012 Jul;169(7):710-8
references.pmid: 22581070
references.citation: Am J Psychiatry. 1997 May;154(5):635-9
references.pmid: 9137118
references.citation: Am J Psychiatry. 2008 May;165(5):579-87
references.pmid: 18413704
references.citation: Am J Psychiatry. 2009 Jan;166(1):50-7
references.pmid: 19047325
references.citation: Schizophr Res. 2003 Dec 15;65(2-3):87-94
references.pmid: 14630301
references.citation: Schizophr Bull. 2007 Nov;33(6):1373-8
references.pmid: 17443013
references.citation: Arch Gen Psychiatry. 2004 Apr;61(4):354-60
references.pmid: 15066893
references.citation: Schizophr Res. 2010 Aug;121(1-3):24-31
references.pmid: 20542412
references.citation: Arch Gen Psychiatry. 2006 Feb;63(2):153-60
references.pmid: 16461857
references.citation: Neuropsychology. 1998 Jul;12(3):426-45
references.pmid: 9673998
references.citation: Schizophr Res. 2000 Dec 15;46(2-3):203-7
references.pmid: 11120432
references.citation: Psychol Med. 2012 Oct;42(10):2057-69
references.pmid: 23206378
references.citation: Can J Psychol. 1962 Mar;16:1-10
references.pmid: 13909749
references.citation: J Clin Exp Neuropsychol. 2006 Feb;28(2):270-82
references.pmid: 16484098
references.citation: Arch Gen Psychiatry. 2007 May;64(5):532-42
references.pmid: 17485605
references.citation: N Engl J Med. 1999 Feb 25;340(8):603-8
references.pmid: 10029644
references.citation: Psychol Med. 2009 Feb;39(2):179-95
references.pmid: 18606047
references.citation: Neuropsychology. 2009 May;23(3):315-36
references.pmid: 19413446
references.citation: J Clin Exp Neuropsychol. 2006 Feb;28(2):225-42
references.pmid: 16484095
references.citation: Am J Epidemiol. 1996 Oct 1;144(7):634-41
references.pmid: 8823058
references.citation: Neuropsychology. 2012 Mar;26(2):181-90
references.pmid: 22201301
references.citation: Nat Rev Drug Discov. 2012 Feb 01;11(2):141-68
references.pmid: 22293568
references.citation: Arch Gen Psychiatry. 1991 Mar;48(3):254-8
references.pmid: 1996920
references.citation: Arch Gen Psychiatry. 2001 Jan;58(1):24-32
references.pmid: 11146755
references.citation: Psychol Med. 2012 Aug;42(8):1649-61
references.pmid: 22153300
references.citation: Schizophr Res. 2006 Dec;88(1-3):26-35
references.pmid: 16930949
references.citation: Arch Gen Psychiatry. 1984 Dec;41(12):1178-82
references.pmid: 6334503
references.citation: Soc Psychiatry Psychiatr Epidemiol. 2005 Oct;40(10):808-16
references.pmid: 16177843
references.citation: Am J Psychiatry. 2010 Feb;167(2):160-9
references.pmid: 20048021
references.citation: Am J Psychiatry. 1999 Sep;156(9):1328-35
references.pmid: 10484941
references.citation: Schizophr Res. 2010 May;118(1-3):1-5
references.pmid: 20153140
references.citation: Arch Gen Psychiatry. 2000 Sep;57(9):907-13
references.pmid: 10986554
references.citation: J Consult Psychol. 1950 Apr;14(2):95-8
references.pmid: 15412212
references.citation: Biol Psychiatry. 1999 Jan 1;45(1):32-40
references.pmid: 9894573
references.citation: Psychol Bull. 2007 Sep;133(5):833-58
references.pmid: 17723032
references.citation: Am J Psychiatry. 1984 Aug;141(8):966-70
references.pmid: 6465372
references.citation: Psychol Med. 2012 Apr;42(4):743-55
references.pmid: 21896236
references.citation: Arch Gen Psychiatry. 2010 Jun;67(6):578-88
references.pmid: 20530007
references.citation: Arch Gen Psychiatry. 2002 May;59(5):449-56
references.pmid: 11982449
references.citation: Arch Gen Psychiatry. 1981 Apr;38(4):381-9
references.pmid: 6260053
references.citation: Schizophr Res. 2005 Apr 1;74(1):15-26
references.pmid: 15694750
references.citation: Schizophr Res. 2008 Oct;105(1-3):1-9
references.pmid: 18774696
references.citation: Am J Psychiatry. 2003 Nov;160(11):2060-2
references.pmid: 14594759
references.citation: Psychol Bull. 1992 Jul;112(1):155-9
references.pmid: 19565683