Double-Edged Sword: A Positive Brain Scan Result Heightens Confidence in an Alzheimer's Diagnosis But Also Leads to Higher Stigma Among Older Adults in a Vignette-Based Experiment.

ABSTRACT

OBJECTIVES: Early diagnosis of Alzheimer's disease (AD) using brain scans and other biomarker tests will be essential to increasing the benefits of emerging disease-modifying therapies, but AD biomarkers may have unintended negative consequences on stigma. We examined how a brain scan result affects AD diagnosis confidence and AD stigma. METHODS: The study used a vignette-based experiment with a 2 × 2 × 3 factorial design of main effects a brain scan result as positive or negative, treatment availability and symptom stage. We sampled 1,283 adults ages 65 and older between June 11and July 3, 2019. Participants (1) rated their confidence in an AD diagnosis in each of four medical evaluations that varied in number and type of diagnostic tools and (2) read a vignette about a fictional patient with varied characteristics before completing the Modified Family Stigma in Alzheimer's Disease Scale (FS-ADS). We examined mean diagnosis confidence by medical evaluation type. We conducted between-group comparisons of diagnosis confidence and FS-ADS scores in the positive versus negative brain scan result conditions and, in the positive condition, by symptom stage and treatment availability. RESULTS: A positive versus negative test result corresponds with higher confidence in an AD diagnosis independent of medical evaluation type (all p < .001). A positive result correlates with stronger reactions on 6 of 7 FS-ADS domains (all p < .001). DISCUSSION: A positive biomarker result heightens AD diagnosis confidence but also correlates with more AD stigma. Our findings inform strategies to promote early diagnosis and clinical discussions with individuals undergoing AD biomarker testing.