Background: Brain volume decreases with normal aging. We sought to determin
e 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 vol
unteers, 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 b
y administering the Revised NEO Personality Inventory.
Results: After statistically controlling for age and sex, neuroticism showe
d a significant negative association with the ratio of brain to the remaind
er of the intracranial volume, but was not related to intracranial volume i
tself. In particular, subfactors of neuroticism related to the chronic expe
rience of arousing negative emotions were associated with reduced brain rat
io.
Conclusions: These results suggest that individual differences in stress re
activity contribute to reductions in brain volume observed during adulthood
. (C) 2001 Society of Biological Psychiatry.