Neuropsychiatric Symptoms and Alzheimer’s Disease Risk Differences across Racial and Ethnic Groups

Abstract

AbstractBackgroundNeuropsychiatric symptoms (NPS) emerging after the age of 50 may be a risk factor or an early clinical expression of AD dementia. Mild Behavioral Impairment (MBI) is a syndrome of new‐onset and persistent NPS in older adults either with or without cognitive impairment. NPS in the context of race and ethnicity have not been studied and the influence of biology or culture on the expression of NPS is unknown.MethodParticipants over the age of 60 ranging from cognitively normal to mild AD (N = 17,491) from the National Alzheimer’s Coordinating Center were categorized for MBI status (yes/no) using Neuropsychiatric Inventory‐Questionnaire (NPI) scores and a published algorithm. MBI prevalence across White non‐Hispanics, White Hispanics, African Americans, and Asians was compared using multivariable logistic regression with adjustment for a priori specified confounding factors including diagnostic group, age, sex, and other relevant factors. Among MBI negative participants at baseline, a Cox proportional hazards model was also fit to estimate the relative risk of progression to MBI across race/ethnicity groups.ResultAfter adjustment, White Hispanics were estimated to have a 2‐fold higher odds of MBI when compared to White non‐Hispanics (OR, 2.03; 95% CI, 1.65‐2.50; p<0.001). In contrast, African Americans were less likely than White non‐Hispanics to have MBI (OR, 0.79; 95% CI, 0.68‐0.92; p<0.003). The odds of MBI were significantly higher among men when compared to women (OR, 1.28; 95% CI, 1.16‐1.41; p<0.001). In the prospective analysis, African Americans were estimated to have 26% lower risk of progressing to MBI when compared to White non‐Hispanics (RR, 0.74; 95% CI, 0.65‐0.84; p<0.001).ConclusionThese findings suggest there are racial/ethnic differences in the prevalence of MBI and the progression to MBI in older adults at risk for or with mild AD dementia. African Americans had a lower likelihood of having MBI and progression to MBI, while White Hispanics had a higher likelihood compared to White non‐Hispanics. Future research is warranted to investigate potential biological features or cultural factors such as the differential expression or perception of NPS in older adults that explain these differences.