Conscientiousness, extraversion, and a positive outlook were associated with a lower risk of developing dementia.
Psychosocial factors, including personality traits and subjective well-being, were strong predictors of dementia diagnosis but were not predictors of neuropathology at autopsy, according to the findings of a meta-analysis published in the journal Alzheimer’s & Dementia.
The big 5 personality traits (conscientiousness, extraversion, openness to experience, neuroticism, and agreeableness) and subjective well-being measures have been associated with dementia, but there is limited concise evidence regarding these risk factors and dementia pathology.
To assess the relationship between psychosocial factors and brain pathology, researchers from Northwestern University in the United States searched publication databases for studies that included data about the big 5 and subjective well-being as well as pathology outcomes. A total of 8 longitudinal samples comprising 44,531 (aged 49-81 at baseline; 26%-61% women) patients who were followed up to 21 years were included in this analysis.
An increased likelihood of a dementia diagnosis was related with neuroticism (b, 0.11; 95% CI, 0.07-0.15) and negative affect (b, 0.13; 95% CI, 0.003-0.24) whereas dementia was less likely among individuals with conscientiousness (b, -0.15; 95% CI, -0.19 to -0.11), positive affect (b, -0.07; 95% CI, -0.14 to -0.01), extraversion (b, -0.05; 95% CI, -0.09 to -0.009), and openness to experience (b, -0.05; 95% CI, -0.11 to 0.000).
Dementia was not related with agreeableness (b, -0.04; 95% CI, -0.09 to 0.01) or satisfaction with life (b, -0.08; 95% CI, -0.16 to 0.006).
Across studies, however, there was no consistent association between psychological characteristics and measures of neuropathology. Overall, 3.7% of estimates reached significance using data from individual samples but no significant signals were replicated across samples.
In a moderation analysis, 3.2% of assessments reached significance. Of these significant signals, 7.38% of moderators were significant for clinical dementia and 0.92% were significant for neuropathology. For example, a significant interaction between conscientiousness and age was observed on the likelihood of dementia (b, 0.005; 95% CI, 0.002-0.008).
The researchers tested whether conscientiousness interacted with a dementia diagnosis to affect the likelihood of neuropathology. They identified no significant association overall (b, 0.10; 95% CI, -0.08 to 0.28) but found that individuals with higher conscientiousness had different Braak stage overall than their clinical dementia diagnosis would indicate.
The major limitation of this study was the lack of access to data about neuropathology markers, in which half of samples did not have complete autopsies.
“[O]ur results suggest a protective effect of openness to experience, positive affect, and satisfaction with life for incident dementia diagnosis, though effects were less consistent across datasets. Although the Big Five and aspects of [subjective well-being] were not associated with neuropathology at autopsy, moderator analyses reveal some evidence that these psychological factors may also act as predispositions that influence neuropathology.”
Note: This article originally appeared on Neurology Advisor
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