3rd May 06:30
This Just In... (dementia)
Neuroticism a Potential Risk Factor for Alzheimer's Disease
NEW YORK (Reuters Health) Dec 09 - Susceptibility to psychological
distress seems to be associated with the risk of Alzheimer's disease
(AD), researchers in Chicago report. If so, it is possible that
antidepressants or other drugs could attenuate the effects of
stressful experience on brain structure and function.
Because chronic stressful experience is linked to structural changes
in the hippocampus and with impaired learning and memory, Dr. Robert
S. Wilson and colleagues at Rush-Presbyterian-St. Luke's Medical
Center hypothesized that propensity to experience psychological
distress is related to risk of AD.
To investigate, they ****yzed data from the longitudinal Religious
Orders Study, which included 797 individuals, average age 75 years,
free of dementia at baseline.
As described in the December 9 issue of Neurology, the subjects
underwent complete neurologic examinations and completed the
Neuroticism scale from the 48-point NEO Five-Factor Inventory. At
annual follow-ups the subjects underwent a battery of 19 cognitive
During mean follow-up of 4.9 years, 140 individuals were diagnosed
After adjusting for age, gender, and education, Dr. Wilson's team
found that each 1-point increase in distress-proneness was associated
with a 6% increased risk of AD and 7% decline in global cognition.
Compared with persons in the 10th percentile, risk was approximately
doubled in persons in the 90th percentile.
Episodic memory, which the investigators note is primarily mediated by
hippocampal formation, was more affected by Neuroticism Scale scores
than were other cognitive systems, such as semantic memory and
The authors were surprised to see that this trait was not associated
with quantitative measures of AD pathology -- plaques and
neurofibrillary tangles -- assessed in autopsy material. They suggest
that the association between chronic psychological distress and AD
"probably reflects neurobiologic mechanisms other than the pathologic
hallmarks of AD."
Dr. Wilson notes in a journal press release that antidepressants and
other drugs may block the adverse effects of stress. "But much more
research is needed before we can determine whether the use of
antidepressants could help reduce the risk of Alzheimer's disease."
"Regardless of whether elevated neuroticism scores are an independent
antecedent of AD dementia or an early sign, the present study
elegantly demonstrates that distress-proneness predicts an increased
risk of clinical AD in an elderly population," Drs. John C. S.
Breitner, with the University of Washington in Seattle, and Dr. Paul
T. Costa, with the National Institute on Aging in Baltimore, remark in
a related editorial.