Certain personality traits — like high levels of neuroticism and low conscientiousness — may be linked to a higher risk of Alzheimer’s disease and other forms of dementia, finds a study published in the journal JAMA Psychiatry.
But people don’t develop these traits are during pre-symptomatic stages of the disease, said the study, which showing that those who become mildly impaired or demented do not experience changes in their personality that might flag the onset of Alzheimer’s.
The study, “Personality Change in the Preclinical Phase of Alzheimer Disease,” debunks the idea that the disease itself modulates such traits, but so far, it has been impossible to assess when these traits appear.
Researchers at Florida State University and the National Institute on Aging — a unit of the National Institutes of Health — suspected that these traits might arise as a consequence of early disease processes that occur decades before Alzheimer’s makes itself known.
To study their hypothesis, they followed 2,046 cognitively healthy older adults for an average of 12 years (and some for up to 36 years). During this time, they often completed personality assessments scoring five personality features: neuroticism, extraversion, openness, agreeableness and conscientiousness. Over time, 104 people (about 5.1 percent of the total) developed mild cognitive impairment, considered a precursor of dementia. Another 255 (12.5 percent) developed dementia in general, 9.5 percent of these Alzheimer’s cases.
The group was composed of 45.5 percent women and 54.5 percent men. Racially speaking, 77.3 percent were of European descent, followed by blacks (18.3 percent), Asian or Pacific islanders (2.7 percent) and other ethnicities (1.7 percent).
The analyses, however, did not confirm the research team’s idea. While those with Alzheimer’s scored higher on neuroticism and lower on conscientiousness and extraversion at the beginning of the study, their personality did not change any more than those who did not develop the disease.
Researchers got similar results looking at people with mild cognitive impairment and all-cause dementia. People who later developed dementia scored higher on neuroticism and lower on conscientiousness, extraversion and openness, while people who developed pre-stage dementia scored lower on openness.
As with the Alzheimer’s group, the all-cause dementia and mild cognitive impairment groups’ personalities did not change differently over time, compared to people with no cognitive issues.
Personality did not appear to change differently over time in those who developed Alzheimer’s or another dementia, but was different from the onset. The information might inform more research into why people who score high on neuroticism are more prone to develop dementia, while other traits appear to increase resilience to the disease.