The Relation Between Personality and Biomarkers in Sensitivity and Conversion to Alzheimer-Type Dementia

Abstract

Objectives:The present study explored relationships among personality, Alzheimer’s disease (AD) biomarkers, and dementia by addressing the following questions: (1) Does personality discriminate healthy aging and earliest detectable stage of AD? (2) Does personality predict conversion from healthy aging to early-stage AD? (3) Do AD biomarkers mediate any observed relationships between personality and dementia status/conversion?Methods:Both self- and informant ratings of personality were obtained in a large well-characterized longitudinal sample of cognitively normal older adults (N = 436) and individuals with early-stage dementia (N = 74). Biomarkers included amyloid imaging, hippocampal volume, cerebral spinal fluid (CSF) Aβ42, and CSF tau.Results:Higher neuroticism, lower conscientiousness, along with all four biomarkers strongly discriminated cognitively normal controls from early-stage AD individuals. The direct effects of neuroticism and conscientiousness were only mediated by hippocampal volume. Conscientiousness along with all biomarkers predicted conversion from healthy aging to early-stage AD; however, none of the biomarkers mediated the relationship between conscientiousness and conversion. Conscientiousness predicted conversion as strongly as the biomarkers, with the exception of hippocampal volume.Conclusions:Conscientiousness and to a lesser extent neuroticism serve as important independent behavioral markers for AD risk.

Relationships between big‐five personality factors and Alzheimer's disease pathology in autosomal dominant Alzheimer's disease

“…Neuroticism tended to increase and conscientiousness to decrease in mutation carriers with the reverse being true in the NC. This pattern is consistent with prior reports of neuroticism and conscientiousness producing the largest differences among those at increased risk for late‐onset AD, 14–17 suggesting that our findings can be generalized to the more common, sporadic form of the disease. We also observed a relationship between personality and EYO in NCs.…”

“…An important aspect of the data collection strategy was that personality was assessed using both self‐report as well as ratings from a collateral source. Other studies in sporadic AD have suggested that collateral source ratings of personality provide more diagnostic information than ratings from the participant; 12,15 thus, we hypothesized that collateral source reports may provide a more sensitive metric by which to gauge personality change in DIAN.…”

“…These same factors typically also show large differences between cognitively healthy older adults and those with either mild, 11 or very mild, dementia 12,13 . Furthermore, evidence suggests that high levels of neuroticism and/or low levels of conscientiousness confer the greatest risk for developing dementia in healthy older adults 14–17 . Given the predictive power of personality, recent guidelines have even suggested incorporating these measures into clinical diagnoses of dementia 18 …”

Neuroticism and Risk of Parkinson's Disease: A Meta‐Analysis

“…Individuals who score high in neuroticism are at higher risk for poor health outcomes across the lifespan, particularly in the domain of mental health [2][3][4] and neurodegenerative diseases, including Alzheimer's disease and related dementias. [5][6][7][8][9] Relatively less is known about the association between neuroticism and Parkinson's disease (PD), 10,11 a multifactorial neurodegenerative disorder characterized by bradykinesia, resting tremor, rigidity, and may include autonomic dysfunctions, cognitive deficits, and mood disorders. 12 The prevalence of PD is about 1% in older adults, 13 and globally it is estimated that over 6 million individuals have PD.…”

Personality pathology predicts increased informant-reported, but not performance-based, cognitive decline: Findings from two samples.

“…The current study addresses this gap in the literature by integrating findings across two longitudinal data sets of community-dwelling older adults. The Knight Alzheimer's disease Research Center (ADRC) in St. Louis has cultivated a pool of participants with detailed cognitive assessments at multiple time points and has already contributed meaningfully to our understanding of the relationship between normal-range personality and cognitive decline (Duchek et al, 2007(Duchek et al, , 2020Schultz et al, 2017). Meanwhile, the St. Louis Personality and Aging Network (SPAN) is the first major, longitudinal study to examine personality pathology as assessed from multiple different perspectives (self, informant, and interview) in community-dwelling older adults (Oltmanns et al, 2014).…”