Does Personality Predict Behavioral and Psychological Symptoms of Dementia? Results from PACO Prospective Study

Background: Premorbid personality could play a role in the onset of behavioral and psychological symptoms (BPS) in Alzheimer's disease (AD) but prospective studies are lacking. Objective: The present study aimed at prospectively assessing the influence of premorbid personality traits on BPS evolution in a population of patients with prodromal or mild AD. Methods: We used a multicenter prospective cohort study of 237 patients followed-up for 18 months. The influence of personality traits on BPS evolution, measured with Neuropsychiatric Inventory (NPI), was assessed using linear mixed-effect models. Results: A principal components analysis of the 12 NPI behavioral domains yielded five factors labelled as psychotic symptoms, affective symptoms, behavioral dyscontrol, apathy/appetite symptoms, and sleep disorders. During the follow-up, higher neuroticism was significantly associated with a higher progression of affective symptoms (p < 0.0001), apathy/appetite symptoms (p = 0.002), sleep disorders (p = 0.001) as well as global NPI scores (p < 0.0001). Greater conscientiousness was related to a lower evolution of psychotic (p = 0.002), affective (p = 0.02) and apathy/appetite symptoms (p = 0.02), and global NPI score (p < 0.0001). Higher openness was associated with lower affective symptoms evolution (p = 0.01). A significant relationship was found between higher extraversion, lower affective symptoms (p = 0.02), and higher behavioral dyscontrol (p = 0.04). Conclusion: The present analysis suggests that premorbid personality may influence the evolution of BPS in prodromal or mild AD. Given these results, it seems important to give more importance to personality assessment in early AD, in order to better identify and manage patients at risk of adverse behavioral changes.