title: Insight Into Illness and Cognition in Schizophrenia in Earlier and Later Life.
abstract: Impaired insight into illness in schizophrenia is associated with illness severity and deficits in premorbid intellectual function, executive function, and memory. A previous study of patients aged 60 years and older found that illness severity and premorbid intellectual function accounted for variance in insight impairment. As such, we aimed to test whether similar relationships would be observed in earlier life.
  
  
  
  A retrospective analysis was performed on 1 large sample of participants (n = 171) with a DSM-IV-TR diagnosis of schizophrenia aged 19 to 79 years acquired from 2 studies: (1) a psychosocial intervention trial for older persons with schizophrenia (June 2008 to May 2014) and (2) a diffusion tensor imaging and genetics study of psychosis across the life span (February 2007 to December 2013). We assessed insight into illness using the Positive and Negative Syndrome Scale (PANSS) item G12 and explored its relationship to illness severity (PANSS total modified), premorbid intellectual function (Wechsler Test of Adult Reading [WTAR]), and cognition.
  
  
  
  Insight impairment was more severe in later life (≥ 60 years) than in earlier years (t = -3.75, P < .001). Across the whole sample, the variance of impaired insight was explained by PANSS total modified (Exp[B] = 1.070, P < .001) and WTAR scores (Exp[B] = 0.970, P = .028). Although age and cognition were correlated with impaired insight, they did not independently contribute to its variance. However, the relationships between impaired insight and illness severity and between impaired insight and cognition, particularly working memory, were stronger in later life than in earlier life.
  
  
  
  These results suggest an opportunity for intervention may exist with cognitive-enhancing neurostimulation or medications to improve insight into illness in schizophrenia across the life span.
  
  
  
  Original study registered on ClinicalTrials.gov (identifier: NCT00832845).
authors.affiliation: FRCPC, Centre for Addiction and Mental Health, 80 Workman Way, 6th Floor, Toronto, ON M6J1H4, Canada. philgerretsen@yahoo.com; philip.gerretsen@camh.ca.|Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Philip
authors.initials: P
authors.lastname: Gerretsen
authors.affiliation: Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Aristotle N
authors.initials: AN
authors.lastname: Voineskos
authors.affiliation: Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Ariel
authors.initials: A
authors.lastname: Graff-Guerrero
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, Canada.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Menon
authors.affiliation: Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Pollock
authors.affiliation: Department of Psychiatry, University of Malta, Msida, Malta.
authors.forename: David C
authors.initials: DC
authors.lastname: Mamo
authors.affiliation: Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Benoit H
authors.initials: BH
authors.lastname: Mulsant
authors.affiliation: Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada.|Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Tarek K
authors.initials: TK
authors.lastname: Rajji
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D059026:Diagnostic Self Evaluation; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D012189:Retrospective Studies; D012559:Schizophrenia / Q000503:physiopathology*; D012720:Severity of Illness Index; D055815:Young Adult