Changes in Personality Before and During Cognitive Impairment

OBJECTIVES: Clinical observations and studies of retrospective observer ratings point to changes in personality in persons with cognitive impairment or dementia. The timing and magnitude of such changes, however, are unclear. This study used prospective self-reported data to examine the trajectories of personality traits before and during cognitive impairment. DESIGN: Longitudinal observational cohort study. SETTING AND PARTICIPANTS: Older adults from the United States in the Health and Retirement Study were assessed for cognitive impairment and completed a measure of the 5 major personality traits every 4 years from 2006 to 2020 (N = 22,611; n = 5507 with cognitive impairment; 50,786 personality and cognitive assessments). METHODS: Multilevel modeling examined changes before and during cognitive impairment, accounting for demographic differences and normative age-related trajectories. RESULTS: Before cognitive impairment was detected, extraversion (b = -0.10, SE = 0.02), agreeableness (b = -0.11, SE = 0.02), and conscientiousness (b = -0.12, SE = 0.02) decreased slightly; there was no significant change in neuroticism (b = 0.04, SE = 0.02) or openness (b = -0.06, SE = 0.02). During cognitive impairment, faster rates of change were found for all 5 personality traits: neuroticism (b = 0.10, SE = 0.03) increased, and extraversion (b = -0.14, SE = 0.03), openness (b = -0.15, SE = 0.03), agreeableness (b = -0.35, SE = 0.03), and conscientiousness (b = -0.34, SE = 0.03) declined. CONCLUSIONS AND IMPLICATIONS: Cognitive impairment is associated with a pattern of detrimental personality changes across the preclinical and clinical stages. Compared with the steeper rate of change during cognitive impairment, the changes were small and inconsistent before impairment, making them unlikely to be useful predictors of incident dementia. The study findings further indicate that individuals can update their personality ratings during the early stages of cognitive impairment, providing valuable information in clinical settings. The results also suggest an acceleration of personality change with the progression to dementia, which may lead to behavioral, emotional, and other psychological symptoms commonly observed in people with cognitive impairment and dementia.