Personality Change and Alzheimer's Disease
Changes in behavior and personality can be indicators of dementia, but Drs. Terracciano and Sutin, along with colleagues from the National Institute on Aging, set out to determine if these changes occur before dementia’s onset. They analyzed data from the Baltimore Longitudinal Study of Aging, a project that spanned 36 years and included personality and clinical assessments from 2,046 older adults. Unique to this study was the availability of personality assessments of individuals who began the study with no cognitive impairment, and developed it later. “About 18% of the sample developed mild cognitive impairment (MCI) or dementia,” Terracciano said. “The study compared whether personality change in people who later developed dementia differed from those who remained cognitively normal."
Their findings, published in the September issue of JAMA Psychiatry, found no evidence to support the idea that personality changes begin before clinical onset was identified. “The trajectory of personality traits and facets for individuals who were later diagnosed with MCI or dementia did not differ significantly from that of non-impaired older adults,” Terracciano said. “We further found that personality remained stable even within the last few years before the onset of MCI.” These results provide evidence against the hypothesis that personality change is a cause of dementia and strengthens evidence for personality traits as a risk factor for dementia.