Cognitive performance before and after the onset of subjective cognitive decline in old age

Abstract

Background Our objectives were (1) to test the association between the report of subjective cognitive decline (SCD) and prospective objective cognitive performance in high age individuals and (2) to study the course of longitudinal cognitive performance before and after the first report of SCD. Methods Cognitively normal elderly participants of the German Study on Ageing, Cognition, and Dementia study (N = 2330) with SCD (subjective decline in memory with and without associated concerns) and without SCD at baseline were assessed over 8 years with regard to immediate and delayed verbal recall, verbal fluency, working memory, and global cognition. Baseline performance and cognitive trajectories were compared between groups. In addition, cognitive trajectories before and after the initial report of SCD (incident SCD) were modelled in those without SCD at baseline. Results Baseline performance in the SCD group was lower and declined more steeply in immediate and delayed verbal recall than in the control group (no SCD at baseline). This effect was more pronounced in the SCD group with concerns. Incident SCD was preceded by decline in immediate and delayed memory and word fluency. Conclusions SCD predicts future memory decline. Incident SCD is related to previous cognitive decline. The latter finding supports the concept of SCD indicating first subtle decline in cognitive performance that characterizes preclinical Alzheimer's disease.

The Cognitive Change Index as a Measure of Self and Informant Perception of Cognitive Decline: Relation to Neuropsychological Tests

“…Similar to previous studies, our study demonstrated that self-perceived cognitive decline was highly correlated with psychological symptoms [16, 19, 21, 45–47], and informant-report of subject’s cognitive decline correlated better than self-report to objective cognitive tests [22, 23]. We used the GDS to assess depressive symptoms in our study.…”

Implementation of subjective cognitive decline criteria in research studies

“…This decline from “normality” to a state with experienced cognitive difficulities only refers to the subjective experience of the individual and not to objective neuropsychological measures, which are by definition within the normal range. Nonetheless, there may be subtle decline from a prior level on objective tests, as demonstrated in studies where SCD was preceded by a subtheshold decline in immediate and delayed verbal recall (24) and by decline in psychomotor processing speed (25). This supports the idea that SCD represents the self-experience of cognitive decline before impairment becomes detectable on standardized neuropsychological tests (2, 7, 8, 24, 26).…”

“…Also normal aging is associated with SCD, however, there are a proportion of elderly individuals, who deny cognitive worsening, even on active inquiry. In a German sample of over 3327 individuals without dementia over the age of 75 (average age 80 years, AgeCoDe study), about 30% answered that they did not experience memory decline (79). Overall, the causes of SCD reporting in individuals are numerous, including age-related factors, personality traits and medical factors, one of which is early neurodegeneration.…”

A Conceptualization of the Utility of Subjective Cognitive Decline in Clinical Trials of Preclinical Alzheimer’s Disease

“…SCD provides valuable predictive information about risk of cognitive decline (Hohman et al 2011; Snitz et al 2015) and future progression to AD dementia (Koppara et al 2015; Reisberg et al 2010; Wang et al 2004). A meta-analysis has suggested an increased annual rate of progression to MCI by 7% or AD dementia by 2% in comparison with those without SCD (Mitchell et al 2014).…”