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Personality changes do not begin before Alzheimer’s disease onset

Changes in personality, specifically neuroticism, conscientiousness and extraversion, did not begin before the onset of mild cognitive impairment or Alzheimer’s disease, according to recent findings.

“Changes in personality and behavior are one clinical criterion for the diagnosis of dementia. Little is known, however, as to whether personality changes before the onset of clinical dementia,” Antonio Terracciano, PhD, of Florida State University, Tallahassee, and colleagues wrote. “The neuropathologic processes that underlie Alzheimer’s disease and related dementias start years before onset of clinical dementia. It is, therefore, possible that changes in personality (eg, loss of motivation or increased irritability) might be an early sign of [Alzheimer’s disease] that precedes the onset of cognitive and functional impairment.”

To determine if increased neuroticism, decreases in conscientiousness and changes in other personality traits occur before mild cognitive impairment (MCI) or dementia onset, researchers evaluated a cohort of 2,046 community-dwelling older adults. Personality and clinical assessments were conducted between 1980 and July 13, 2016. Study participants were followed for as long as 36 years. Mean age at first assessment was 62.56 years.

During 24,569 person-years, 5.1% of participants were diagnosed with MCI and 12.5% were diagnosed with all-cause dementia, including 9.5% with Alzheimer’s disease.

Analysis accounting for age, sex, race and educational level indicated participants who developed dementia scored higher on neuroticism (P < .001) and lower on conscientiousness (P < .001) and extraversion (P = .02).

However, change in personality was not significantly different between nonimpaired participants and those with Alzheimer’s disease.

Personality change for participants who developed MCI and all-cause dementia was comparable to the change observed in nonimpaired participants.

“This study found that change in personality does not initiate before the onset of MCI or [Alzheimer’s disease]. The findings are contrary to the reverse causality hypothesis and provide further support that personality traits are a risk factor for the development of dementia,” the researchers concluded. – by Amanda Oldt

Disclosures: The authors report no relevant financial disclosures.