title: Caudate volume measurement in older adults with bipolar disorder.
abstract: BACKGROUND
  Decreased caudate volumes have been noted in unipolar depressed subjects, especially in the elderly and those with cognitive impairment. No differences have been noted in initial studies of multi-aged bipolar subjects; however, this region has not been examined in older bipolar subjects.
  
  
  METHODS
  We examined the caudate nuclei volumes of 36 older bipolar subjects (mean age 58) and 35 older controls (mean age 62) using logistic regression analyses to control for age and gender differences. Differences between late- and early-onset (age-of-onset before age 45) bipolar subjects were also examined, as well as the effect of length of illness.
  
  
  RESULTS
  The right caudate was noted to be smaller in older bipolar subjects compared with older controls when controlled for sex and age (p = 0.0448). No differences were noted in overall brain volume nor lateral ventricular volume between the bipolar and control subjects. Late-onset bipolar subjects had a decrease in brain volume (p = 0.035) compared with early-onset bipolar subjects. Late-onset bipolar subjects had a decrease in the right (p = 0.044) and total (p = 0.04) caudate size compared with older controls.
  
  
  CONCLUSIONS
  Right caudate volume is decreased in older bipolar subjects compared to controls. Bipolar subjects with late-onset illness have significantly decreased right and total caudate volumes compared to controls. This is affected by neither the length of illness nor the age of onset. Late-onset bipolar subjects have decreased total brain volume compared with early-onset bipolar subjects.
authors.affiliation: Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA. Beyer001@mc.duke.edu
authors.forename: John L
authors.initials: JL
authors.lastname: Beyer
authors.forename: Maragatha
authors.initials: M
authors.lastname: Kuchibhatla
authors.forename: Martha
authors.initials: M
authors.lastname: Payne
authors.forename: Melissa
authors.initials: M
authors.lastname: Moo-Young
authors.forename: Frederick
authors.initials: F
authors.lastname: Cassidy
authors.forename: James
authors.initials: J
authors.lastname: MacFall
authors.forename: K Ranga R
authors.initials: KR
authors.lastname: Krishnan
mesh_terms: D017668:Age of Onset; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis*; D001921:Brain / Q000473:pathology; D002421:Caudate Nucleus / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged