Phenomenological characterization of memory complaints in preclinical and prodromal Alzheimer's disease

To explore the subjective experience of memory change in groups at risk of dementia (those with mild cognitive impairment MCI or high β-amyloid (Aβ+) burden) to determine the existence of potential phenomenological typologies.

We recruited 123 healthy controls (HC) and individuals with MCI from the Australian Imaging, Biomarker and Lifestyle (AIBL) study. Sixty-7 (HC = 47,MCI = 20) had Aβ scans available for analysis. Semistructured interviews were administered, transcribed, and meaningful phrases extracted from transcripts. Twelve themes were defined and compared across diagnostic status and Aβ status.

MCI endorsed more complaints of burdensome coping strategies, increasing frequency, sense of predomination, poor contextualization, progression, dependency, impact on affect, and dismissive attitudes. HCAβ+ acknowledged a progressive memory decline compared to HCAβ-, while MCIAβ+ expressed more burdensome coping strategies, dismissive attitudes, and dependency comparative to either healthy group. Depression was more likely to be related to complaint themes in HCs, while complaint themes were associated with poorer list-learning performance in individuals with MCI.

Complaint themes in those with MCI align with the MCI symptom complex, particularly when accompanied with high Aβ load. Healthy Aβ+ individuals acknowledged progressive memory change, suggesting they are aware of memory changes not yet detectable via neuropsychological measures. Depressive symptomatology associated with HC complaints, suggesting certain themes are affect-driven, while complaints in MCI are associated with organically driven functional impairment. Qualitative analysis of SMCs can inform the earliest clinical manifestations of Alzheimer's disease. Our findings can inform diagnostic approaches to the clinical evaluation of memory complaints in the nondemented elderly.