title: Influence of cognitive reserve on neuropsychological functioning in bipolar disorder: Findings from a 5-year longitudinal study.
abstract: The present study examined the 5-year longitudinal course of cognitive functioning in a large sample of well-characterized patients with bipolar disorder (BP), compared to healthy controls (HCs), and the influence of cognitive reserve factors (e.g., education and IQ) on cognitive change over time.
  
  
  
  Participants included 159 individuals diagnosed with BP and 54 HCs recruited as part of a longitudinal naturalistic study of BP who had completed neuropsychological testing at the time of their enrollment and again 5 years later.
  
  
  
  The overall relative rate of change did not differ between the BP and HC groups. In total, 46.5% of the BP group and 37% of the HC group showed evidence of decline on at least one measure over time. T-test analyses did not find differences between BP 'decliners' and 'non-decliners' in cognitive reserve variables. However, we found that higher baseline intellectual ability was associated with more stability in cognitive test scores over time for the BP group. Results of linear regression modeling revealed that lower verbal IQ and education were related to increased cognitive decline in specific domains in the BP group.
  
  
  
  This study has explored the influence of cognitive reserve on preservation of specific cognitive abilities over time in BP. The BP group did not demonstrate accelerated cognitive decline over 5 years compared to the HC group. Although the trajectory of cognitive change over time was similar between BP patients and HCs, higher overall intellectual ability may be a protective factor against cognitive decline, particularly for BP patients.
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Kristin H
authors.identifier: 0000-0002-8345-2277
authors.initials: KH
authors.lastname: Hinrichs
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Easter
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Kaley
authors.initials: K
authors.lastname: Angers
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Pester
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Zongshan
authors.initials: Z
authors.lastname: Lai
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Marshall
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.|Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Masoud
authors.initials: M
authors.lastname: Kamali
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Melvin
authors.initials: M
authors.lastname: McInnis
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Langenecker
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Ryan
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000523:psychology; D003071:Cognition; D058245:Cognitive Reserve; D004522:Educational Status; D005260:Female; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D007807:Language Tests; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged
keywords: bipolar disorder; clinical neuropsychology; cognitive reserve