The natural history of subjective complaints, awareness and metacognition in AD

Abstract

AbstractBackgroundSubjective cognitive decline (SCD) is the self‐reported experience of decrease in cognitive function in absence of cognitive impairment. This condition is common in elderly subjects and is a frequent reason for referral to memory clinics. SCD is often considered as a stage antedating objective impairment, and an at‐risk condition for subsequent dementia. Recent large‐scale studies, however, support an increased risk only in subjects positive for Alzheimer’s disease (AD) biomarkers, confirming that SCD can be due to multiple mechanisms, including functional cognitive disorders.MethodThis work have reviewed the current research on the awareness of cognitive decline (ACD), with a focus on metacognitive abilities and on assessment tools. The findings from studies of ACD during the course of AD are also reviewed for their possible impact on clinical management.ResultWe propose that, in presence of normal cognitive performance, a subjective overestimation of objective cognitive performance may be a negative prognostic marker, while subjective overestimation of cognitive decline may be compatible with healthy aging or the presence of a functional cognitive disorder.ConclusionLongitudinal studies are needed to test the usefulness of metacognition measures to select SCD subjects for biomarker assessment and/or metacognitive training.