title: Negative association of neuroticism with brain volume ratio in healthy humans.
abstract: BACKGROUND
  Brain volume decreases with normal aging. We sought to determine whether, in addition to age, individual differences in stress reactivity (i.e., neuroticism) would also predict reductions in brain volume.
  
  
  METHODS
  Brain volume ratios were calculated for a sample of 86 healthy volunteers, based on segmented brain volumes taken from T(1)-weighted magnetic resonance imaging and corrected for intracranial volume. Standardized self-reported measures of dispositional neuroticism were concurrently obtained by administering the Revised NEO Personality Inventory.
  
  
  RESULTS
  After statistically controlling for age and sex, neuroticism showed a significant negative association with the ratio of brain to the remainder of the intracranial volume, but was not related to intracranial volume itself. In particular, subfactors of neuroticism related to the chronic experience of arousing negative emotions were associated with reduced brain ratio.
  
  
  CONCLUSIONS
  These results suggest that individual differences in stress reactivity contribute to reductions in brain volume observed during adulthood.
authors.affiliation: Laboratory of Clinical Studies, Section on Brain Imaging and Electrophysiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892-1610, USA.
authors.forename: B
authors.initials: B
authors.lastname: Knutson
authors.forename: R
authors.initials: R
authors.lastname: Momenan
authors.forename: R R
authors.initials: RR
authors.lastname: Rawlings
authors.forename: G W
authors.initials: GW
authors.lastname: Fong
authors.forename: D
authors.initials: D
authors.lastname: Hommer
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009497:Neurotic Disorders / Q000175:diagnosis / Q000209:etiology*; D010552:Personality Assessment