de Wilde A, Reimand J, Teunissen CE, et al. - In this study including 768 patients, researchers investigated how clinical features, biomarkers, and longitudinal cognitive trajectories were influenced by having discordant amyloid-β PET (positron emission tomography) and CSF (cerebrospinal fluid) biomarkers in individuals with subjective cognitive decline (n = 194), mild cognitive impairment (n = 127), Alzheimer dementia (AD; n = 309), and 138 non-AD. Based on CSF and PET results, the participants were classified as concordant-negative (n = 315, 41%), discordant (n = 97, 13%), or concordant-positive (n = 356, 46%). As for genetic (Apolipoprotein E ε4) and CSF (tau) markers of AD, it was found that discordant cases were intermediate to concordant-negative and concordant-positive patients. In patients with dementia, cognition remained unaltered by biomarker agreement but in those without dementia, discordant biomarkers were not benign given the higher risk of clinical progression in these individuals.