Abnormal FDG-PET Patterns and Amyloid Positivity Predict Personality Changes in Cognitively Preserved Individuals.

Background/Objectives: Clinically overt Alzheimer's disease (AD) is associated with significant changes in personality factors. Earlier studies indicated that personality factors do not remain stable in elderly controls. Whether the early presence of AD neuroimaging markers may predict subsequent changes in personality factors is still debatable. Methods: To address this issue, we examined the association between Big Five factor scores and baseline AD and vascular imaging markers in a previously established cohort of 58 elderly controls with a 4.5-year follow-up. Personality was assessed with the Neuroticism-Extraversion-Openness Personality Inventory-Revised scale at inclusion and 55-month follow-up. Regression models were used to identify predictors of personality factor changes including time, age, sex, APOE epsilon 4 allele, baseline MMSE scores, amyloid PET positivity, abnormal FDG-PET patterns, mesial temporal lobe atrophy and Fazekas scores, and number of microbleeds. Results: In both univariate and multivariable models, the decrease in openness was related to abnormal FDG PET patterns. This single variable explained 15% of the variance of this personality factor. In univariate models, lower MMSE scores and amyloid positivity at baseline were associated with a subsequent decrease in agreeableness scores. In multivariable models, these two parameters explained 11% and 8% of variance respectively. The other personality factors were not associated with AD and cerebrovascular imaging markers. Conclusions: Personality patterns at baseline may impact the emergence of AD pathology but they may also change rapidly as a function of the presence of early AD-related PET abnormalities.