title: Cognitive impairment in early and late bipolar disorder.
abstract: BACKGROUND
  Late onset disorders are often associated with cerebral disfunctioning and cognitive impairment in elderly patients. It is unknown whether the age of onset affects cognition in patients with bipolar disorder. The authors compare cognition and clinical characteristics of early- and late-onset bipolar patients in a stable and euthymic condition.
  
  
  METHODS
  One hundred and nineteen older patients (age >60) with an early- (<40 years) or late-onset bipolar disorder and a group of 78 comparison subjects were extensively tested for cognitive functioning.
  
  
  RESULTS
  Bipolar subjects scored lower on most cognitive measures. The late-onset patients were more impaired in psychomotor performance and mental flexibility than the early-onset patients. These differences could not be explained by differences in exposure to cerebrovascular risk factors.
  
  
  CONCLUSIONS
  Older patients with bipolar disorder have substantial cognitive impairments. Late onset bipolar disorder is associated with more severe cognitive impairment than early-onset bipolar disorder. For clinical practice, it is important to develop treatment strategies which take this into account.
authors.affiliation: Stichting Buitenamstel Geestgronden, Amsterdam. sigfries@ggzba.nl
authors.forename: Sigfried N T M
authors.initials: SN
authors.lastname: Schouws
authors.forename: Hannie C
authors.initials: HC
authors.lastname: Comijs
authors.forename: Max L
authors.initials: ML
authors.lastname: Stek
authors.forename: Jack
authors.initials: J
authors.lastname: Dekker
authors.forename: Frits
authors.initials: F
authors.lastname: Oostervink
authors.forename: Paul
authors.initials: P
authors.lastname: Naarding
authors.forename: Iet
authors.initials: I
authors.lastname: van der Velde
authors.forename: Aartjan T F
authors.initials: AT
authors.lastname: Beekman
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D001714:Bipolar Disorder / Q000150:complications / Q000453:epidemiology / Q000523:psychology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric