Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD.

BACKGROUND Lack of awareness of cognitive decline (ACD) is common in late-stage Alzheimer's disease (AD). Recent studies showed that ACD can also be reduced in the early stages. METHODS We described different trends of evolution of ACD over 3 years in a cohort of memory-complainers and their association to amyloid burden and brain metabolism. We studied the impact of ACD at baseline on cognitive scores' evolution and the association between longitudinal changes in ACD and in cognitive score. RESULTS 76.8% of subjects constantly had an accurate ACD (reference class). 18.95% showed a steadily heightened ACD and were comparable to those with accurate ACD in terms of demographic characteristics and AD biomarkers. 4.25% constantly showed low ACD, had significantly higher amyloid burden than the reference class, and were mostly men. We found no overall effect of baseline ACD on cognitive scores' evolution and no association between longitudinal changes in ACD and in cognitive scores. CONCLUSIONS ACD begins to decrease during the preclinical phase in a group of individuals, who are of great interest and need to be further characterized. TRIAL REGISTRATION The present study was conducted as part of the INSIGHT-PreAD study. The identification number of INSIGHT-PreAD study (ID-RCB) is 2012-A01731-42.