Although personality was linked to cognitive performance on tests, it was not linked to dementia pathophysiology.
People with certain personality traits—including conscientiousness, extraversion, and positive affect—might have a lower risk of developing dementia, according to research from the University of California (UC) Davis and Northwestern University that was published in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association. Additionally, people with higher neuroticism and negative affect scores had a higher risk of dementia diagnosis, although there was no observable link between these personality traits and brain neuropathology associated with dementia.
“This was the most surprising finding to us,” said first author Emorie Beck, assistant professor of psychology at UC Davis, in a recent press release. “If personality is predictive of performance on cognitive tests but not pathology, what might be happening?”
UC Davis and Northwestern researchers conducted a larger-scale study to evaluate the link between personality traits and dementia diagnosis risk. The study included 44000 people who were previously enrolled in 8 studies (1703 people developed dementia), and the participants’ personalities were measured using the “big 5” personality test. This test consists of 5 personality traits—conscientiousness, extraversion, openness to experience, neuroticism, and agreeableness—that largely make up a person’s personality.
The team also evaluated each patient’s subjective wellbeing—this encompasses positive and negative affect (the extent of feeling positive or negative moods) and life satisfaction. Finally, investigators compared the clinical symptoms of dementia, such as a performance on cognitive tests, and the patients’ brain pathology at autopsy.
The results of the study showed that individuals with higher scores for negative traits, which include neuroticism and negative affect, and lower scores for positive traits had a worse associated risk of developing dementia. Those with a tendency toward openness, agreeableness, and positive subjective wellbeing had more protection against developing dementia, based on the results of a subset of studies.
People with higher conscientiousness scores may have less of a risk of developing dementia as well. Beck says that people who are more conscientious could be more willing to follow healthy behaviors like clean eating, and this could lead to longer term health and reduced risk of dementia.
Investigators also evaluated the influence of age, gender, and education on the relationship between dementia diagnosis risk, neuropathology, and personality, but these factors did not heavily influence risk or pathology. Conscientiousness was the only personality trait linked to age, whereby conscientiousness became more protective as people got older, Beck explained in the press release.
If the association between personality trait and dementia were to be eventually confirmed, then interventions that target personality traits in earlier life may reduce dementia risk. Some hypotheses point to certain personality traits increasing resilience against neurodegenerative diseases, and investigators will conduct further research on personality, dementia pathology, and cognitive impairment in patients who show a lot of pathology and little impairment.
Conscientious personalities less at risk of dementia diagnosis. University of California, Davis. News Release. November 29, 2023. Accessed on November 29, 2023. https://www.eurekalert.org/news-releases/1009240