Subjective Cognitive Decline in Preclinical Alzheimer's Disease

Older adults with subjective cognitive decline (SCD) in the absence of objective neuropsychological dysfunction are increasingly viewed as at risk for non-normative cognitive decline and eventual progression to Alzheimer's disease (AD) dementia. The past decade has witnessed tremendous growth in research on SCD, which may reflect the recognition of SCD as the earliest symptomatic manifestation of AD. Yet methodological challenges associated with establishing common assessment and classification procedures hamper the construct. This article reviews essential features of SCD associated with preclinical AD and current measurement approaches, highlighting challenges in harmonizing study findings across settings. We consider the relation of SCD to important variables and outcomes (e.g., AD biomarkers, clinical progression). We also examine the role of self- and informant-reports in SCD and various psychological, medical, and demographic factors that influence the self-report of cognition. We conclude with a discussion of intervention strategies for SCD, ethical considerations, and future research priorities.