Personality traits distinguishing dementia with Lewy bodies from Alzheimer disease.

OBJECTIVE: To identify personality traits that distinguish dementia with Lewy bodies (DLB) from Alzheimer disease (AD).
METHODS: We examined 290 participants enrolled in a longitudinal study (nondemented control = 34, DLB = 128, AD = 128) followed to autopsy. As part of the annual interview with the collateral source, the clinician asked about specific changes in personality, interests, and drives based on items from the Blessed Dementia Scale (BDS). Statistical analysis was performed using chi(2) and Fisher exact tests. Factor analysis was performed to determine underlying structure and receiver operating characteristic curves assessed the ability for each of three derived factors to discriminate DLB from AD.
RESULTS: The sample was evaluated for a mean of 4.8 visits (range 1 to 14) with a mean age of 77.6 +/- 9.9 years. The participants' cognitive status ranged from nondemented (Clinical Dementia Rating [CDR] 0) through all stages of dementia (CDR > or = 0.5). Personality traits that distinguished DLB included diminished emotional responsiveness (p = 0.004), relinquishing hobbies (p = 0.01), growing apathy (p = 0.03), and purposeless hyperactivity (p = 0.003). Factor analyses of the BDS revealed a PASSIVE factor (diminished emotional responsiveness, relinquished hobbies, growing apathy, and purposeless hyperactivity) explaining 10.4% of variance and that DLB was more likely to manifest these personality traits than AD (p = 0.001). The PASSIVE factor discriminated DLB from AD (area under the curve = 0.61, 95% CI: 0.54 to 0.68, p = 0.006). Any change in personality is associated with the presence of visual hallucinations.
CONCLUSIONS: Our results suggest that incorporating a brief, simple inventory of personality traits may improve the identification of individuals with dementia with Lewy bodies.