Clinical Manifestations

Area of Science:

• Neuroscience
• Gerontology
• Cognitive Psychology

Background:

• Subjective memory decline (SMD) is a potential early marker for Alzheimer's disease (AD).
• Previous studies show mixed results linking SMD to objective memory and AD-related brain changes, possibly due to single-item measures.
• The Everyday Cognition scale (ECog) uses multiple items and informant reports to better detect early AD risk.

Purpose of the Study:

• To assess the association between ECog-measured SMD and objective memory.
• To examine the link between ECog-SMD and AD-related neurodegeneration.
• To determine if ECog-SMD predicts future changes in memory and brain structure.

Main Methods:

• Utilized data from the Vietnam Era Twin Study of Aging (VETSA) with cognitively unimpaired men.
• Administered the ECog memory subscale to participants and informants at two time points (mean ages 68 and 74).
• Assessed objective memory via latent factor scores and AD brain signature using MRI-derived hippocampal volume and cortical thickness.

Main Results:

• ECog-SMD correlated with poorer objective memory and lower AD brain signature scores concurrently.
• ECog-SMD predicted future declines in objective memory and reductions in AD brain signature.
• Increases in ECog-SMD were linked to memory decline but not significantly to changes in AD brain signatures at the second time point.

Conclusions:

• Participant and informant ECog ratings of SMD reflect current objective memory and AD-related neurodegeneration.
• Participant-reported SMD shows potential for identifying future AD-related neurodegeneration, possibly surpassing other assessment methods.