Personality traits and measures of neuropsychiatric symptoms.

Objectives: Changes in personality and behavioral symptoms are a core clinical criterion for the diagnosis of dementia. This study examines the association between caregiver-rated personality traits and multiple measures of neuropsychiatric symptoms.

Method: Caregivers of individuals with dementia (N = 191) or cancer (N = 137) provided premorbid and concurrent personality trait ratings using the Big Five Inventory-2. Caregivers also completed the Mild Behavioral Impairment Checklist, Neuropsychiatric Inventory Questionnaire, and Revised Memory and Behavior Problems Checklist.

Results: In the combined sample, high concurrent neuroticism was associated with emotional dysregulation (r = 0.51), low agreeableness with impulse dyscontrol (r=-0.40), and low conscientiousness with decreased motivation (r=-0.42). Associations were similar across neuropsychiatric symptom scales, similar across cancer and dementia, but stronger with concurrent than premorbid personality ratings, and stronger for the individuals with mild than moderate-severe dementia.

Conclusion: Personality was associated with neuropsychiatric symptoms, including with the measure for mild behavioral impairment. Personality had stronger associations when concurrently assessed, indicating that personality traits co-develop with neuropsychiatric symptoms. The associations were similar across cancer and dementia, suggesting transdiagnostic processes not limited to dementia. Neuropsychiatric symptoms are partly an expression of personality; accounting for personality traits could help with diagnosis and disease monitoring, tailoring interventions, and fostering person-centered care.