Premorbid Personality in Alzheimer's Disease and Caregiver Well-Being: The Role of Extraversion

Objectives: To examine the association between premorbid personality in people with Alzheimer's disease and caregiver well-being, while accounting for caregiver personality, sociodemographic characteristics, and behavioural and psychological symptoms of dementia. Methods: This cross-sectional observational study included 56 dyads consisting of people with mild-to-moderate Alzheimer's disease and their informal caregiver. Caregiver well-being was operationalised using a continuous index derived from a principal component analysis integrating depressive and anxiety symptoms, burden, loneliness, perceived social support, quality of life and happiness. Caregiver personality and the premorbid personality of people with Alzheimer's disease (assessed retrospectively by an informant) were assessed according to the Big Five model. Behavioural and psychological symptoms of dementia were assessed using the Neuropsychiatric Inventory. Associations were examined using correlation analyses and hierarchical multiple linear regression models. Results: Caregivers had a mean age of 55.2 years (SD = 11.0), and 82.1% were women. Higher premorbid extraversion of people with Alzheimer's disease was significantly associated with better caregiver well-being (β = 0.123; p < 0.05), and this association remained significant after adjustment for caregiver personality and other covariates. The final model explained 57.3% of the variance in caregiver well-being (R² = 0.573; p < 0.001). Conclusions: Premorbid extraversion of people with Alzheimer's disease was independently associated with caregiver well-being. These findings suggest that personality characteristics of both may be relevant for understanding caregiver well-being within a relational perspective of caregiving.