Personality traits are related to measures of neurodegeneration
Certain personality traits, including neuroticism, are associated with increased levels of biomarkers that signal neurodegeneration, according to an NIA study. The research, published in Neurobiology of Aging, also found that traits of extraversion, such as assertiveness and high energy, are linked to lower levels of neurodegeneration. These associations were detected in people without cognitive impairment and were independent of other risk factors for neurodegeneration.
Previous research has linked personality traits with risk of dementia such as Alzheimer’s disease, including the formation of amyloid and tau deposits in the brain. In this study, a research team led by scientists at NIA and Florida State University explored whether personality traits are related to neurodegeneration, which is the progressive loss of nerve cell structure and function leading to cellular death.
The team analyzed the results of personality questionnaires and blood samples from 786 participants with normal cognition enrolled in the Baltimore Longitudinal Study of Aging (BLSA). The blood tests measured two proteins that increase with neurodegeneration: glial fibrillary acidic protein (GFAP), which rises with the immune system’s response to damage and disease in the central nervous system, and neurofilament light (NfL), a marker for nerve cell injury.
The team found that higher neuroticism — particularly vulnerability to stress, anxiety, and depression — and lower conscientiousness were associated with higher GFAP and NfL. People with the most emotional vulnerability, meaning they are likely to panic or feel helpless when facing emergencies or stressful conditions, had the highest levels of these markers for neurodegeneration.
In contrast, extraversion was associated with lower levels of GFAP and NfL. Notably, this association was not due to sociability, but to characteristics that seemed to provide some protection against neurodegeneration, such as being cheerful, assertive, and energetic. These findings are consistent with other research that links people with a greater sense of well-being, including happiness and life purpose, with better cognitive health and lower risk of dementia.
The findings in this study were largely consistent regardless of participant age, gender, genetic risk for Alzheimer’s, education, or behaviors. BLSA participants tend to be highly educated, and consequently, more research is needed to test these associations with participants with a broader range of education and economic status. Nonetheless, the findings of this study provide new information about the biological connections between personality traits and the risk of developing neurodegenerative diseases such as Alzheimer’s.
This research was supported in part by the Intramural Research Program of NIA and NIA grants AG068093 and AG053297.
These activities relate to NIH’s AD+ADRD Research Implementation Milestone 2.A, “Create new research programs that use data-driven, systems-based approaches to integrate the study of fundamental biology of aging with neurobiology of aging and research on neurodegeneration, AD and AD-related dementias to better understand the mechanism(s) of vulnerability and resilience in AD across all levels of biologic complexity (from cellular to population level) and to gain a deeper understanding of the complex biology and integrative physiology of healthy and pathologic brain aging.”
Terracciano A, et al. The association between personality and plasma biomarkers of astrogliosis and neuronal injury. Neurobiology of Aging. 2023;128:65-73. doi:10.1016/j.neurobiolaging.2023.04.011.