Findings from a study published in JAMA Psychiatry showed no significant preclinical change in self-rated personality before the onset of mild cognitive impairment (MCI) or clinical dementia.
Researchers analyzed 2046 community-dwelling older adults who volunteered to participate in the Baltimore Longitudinal Study of Aging and had no cognitive impairment at first assessment. Participants underwent personality and clinical assessments between 1980 and July 13, 2016, and were evaluated using the Revised NEO Personality inventory, a 240-item questionnaire that assesses 30 facets, 6 for each of the 5 major dimensions: neuroticism, extraversion, openness, agreeableness, and conscientiousness.
Participants in whom dementia developed scored higher on neuroticism (β=2.83; P <.001) and lower on conscientiousness (β=–3.34; P <.001) and extraversion (β=–1.74; P <.02) than those who were nonimpaired. No significant difference in change in personality was found between the nonimpaired and Alzheimer disease groups, or between the nonimpaired and MCI and all-cause dementia groups.
“These findings provide evidence against the reverse causality hypothesis and strengthen evidence for personality traits as a risk factor for dementia,” the researchers wrote.
The investigators suggest that more research is needed on the correlation between personality and Alzheimer disease biomarkers and how personality may increase resistance against neuropathology and prevent or delay the development of clinical dementia.
Study limitations included the use of a selective population sample with a higher educational level, and the relatively younger age of nonimpaired participants, some of whom may go on to have dementia develop. However, the large sample size and that these findings are consistent with those from previous studies counterbalance these weaknesses.
Terracciano A, An Y, Sutin AR, Thambisetty M, Resnick SM. Personality change in the preclinical phase of Alzheimer disease [published online September 20, 2017]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2017.2816