Supplementary Material for: Conscientiousness Is Associated with Lower Risk of Dementia among Black and White Older Adults

<b><i>Background:</i></b> While some personality traits may reduce risk of dementia, this is controversial and has not been studied as much among diverse populations. We examined associations between 2 traits – Conscientiousness and Openness to Experience – and risk of dementia among black and white older adults. <b><i>Methods:</i></b> We studied 875 older adults (ages 71–82, 47% black) without prevalent dementia from the Health, Aging and Body Composition study, who completed the NEO Five-Factor Inventory for Conscientiousness and Openness to Experience. Incident dementia over 8 years (mean = 6.9 years) was determined by hospital records, medications, or ≥1.5 SD race-specific decline on the Modified Mini-Mental State Examination. In adjusted models, we investigated associations between each trait and risk of dementia, including for race interactions. <b><i>Results:</i></b> Associations between personality traits and dementia risk did not differ by race (interactions: <i>p</i> &gt; 0.7). Higher Conscientiousness was associated with lower dementia risk (adjusted HR per 1SD = 0.78; 95% CI 0.65–0.94). There was no association for Openness to Experience (adjusted HR per 1SD = 0.88; 95% CI 0.71–1.08). <b><i>Conclusions:</i></b> Higher Conscientiousness is associated with lower dementia risk, even among diverse populations. Higher Conscientiousness may be protective, or lower Conscientiousness may be an early symptom of neurodegenerative disease.

<b><i>研究背景：</i></b> 尽管部分人格特质或可降低痴呆症的发病风险，但该结论尚存争议，且针对多元人群的相关研究较为匮乏。本研究针对两种人格特质——尽责性（Conscientiousness）与开放性（Openness to Experience），探讨其在黑人和白人老年人群中与痴呆症发病风险的关联。<b><i>研究方法：</i></b> 本研究纳入来自健康、衰老与身体成分研究（Health, Aging and Body Composition Study）的875名基线无痴呆症的老年受试者（年龄71~82岁，其中黑人占比47%），所有受试者均完成了针对尽责性与开放性维度的NEO五因素问卷（NEO Five-Factor Inventory）。随访8年（平均随访时长6.9年）期间的新发痴呆症病例，通过病历记录、用药史，或基于种族特异性的修正版迷你精神状态检查（Modified Mini-Mental State Examination）得分下降≥1.5个标准差（SD）进行判定。在调整后的回归模型中，本研究分析了两种人格特质分别与痴呆症发病风险的关联，并纳入种族交互项进行检验。<b><i>研究结果：</i></b> 人格特质与痴呆症发病风险的关联不存在种族差异（交互项检验：p > 0.7）。更高的尽责性得分与更低的痴呆症发病风险相关（调整后每1个标准差得分变化对应的风险比（Hazard Ratio, HR）=0.78；95%置信区间（Confidence Interval, CI）：0.65~0.94）。而开放性得分与痴呆症发病风险无显著关联（调整后HR=0.88；95%CI：0.71~1.08）。<b><i>研究结论：</i></b> 即使在多元人群中，更高的尽责性仍与更低的痴呆症发病风险相关。这一结果提示，较高的尽责性或可对痴呆症起到保护作用，而较低的尽责性则可能是神经退行性疾病的早期临床表现。