The role of race/ethnicity, psychiatric history, and substance use in the risk of dementia subtypes: Findings from the NACC

Abstract

AbstractBackgroundDementia is characterized by significant declines in cognitive and physical functioning and includes multiple subtypes that differ in etiology. There is limited evidence of the influence of psychiatric and substance use history on the risk of dementia subtypes among underrepresented racial/ethnic minorities. The study explored the role of psychiatric and substance use history on the risk of etiology‐specific dementias: Alzheimer’s disease (AD) and vascular dementia (VaD), in the context of a racially and ethnically diverse sample based on national data in the US.MethodWe conducted secondary data analyses based on the National Alzheimer’s Coordinating Center Uniform Data Set (N = 17,592). Participants completed at least two visits and were dementia‐free at baseline, and were assessed for history of five psychiatric and substance use disorders (depression, traumatic brain injury, other psychiatric disorders, alcohol use, and other substance use). Cox proportional hazard models were estimated to examine the influence of psychiatric and substance use history on the risk of two dementia subtypes, and the interactions between psychiatric and substance use history and race/ethnicity with adjustment for demographic and health‐related factors.ResultIn addition to other substance use, having any one type of psychiatric and substance use history increased the risk of developing AD by 22‐51% and VaD by 22‐53%. The risk of other psychiatric disorders on AD and VaD risk varied by race/ethnicity. For Non‐Hispanic White, history of other psychiatric disorders increased AD risk by 27% and VaD risk by 116%. For African Americans, AD risk increased by 28% and VaD risk increased by 108% when other psychiatric disorder history was present.ConclusionThe findings indicate that having psychiatric and substance use history increases the risk of developing AD and VaD in later life. Preventing the onset and recurrence of such disorders may prevent or delay the onset AD and VaD dementia subtypes. Prevention efforts should pay particular attention to Non‐Hispanic White and African American older adults who have history of other psychiatric disorders.