Subjective memory deficits without emotional concern predicts decline in cognitive functioning

Abstract

Introduction: Impaired memory and cognitive performance are known to be correlated with depression. However, when these three factors are present among the elderly population, it becomes complicated. While memory and cognitive performance degradation may be symptoms of depression, it may also be an indication of a clinically significant cognitive decline, which can lead to a very different conceptualization and treatment. Objectives: This study aims to explore the interplay between the factor of memory performance, cognitive performance, and symptoms of depression, and identify predictors to cognitive decline among the elderly population. Methods: Our study followed 1414 healthy community-dwelling older persons aged 65 or above in Hong Kong for a year, measuring their depressive symptoms with Geriatric Depression Scale (GDS), subjective memory deficits with an item from GDS, concern on memory deficits with a stand-alone dichotomous question, and cognitive performance with Cantonese Montreal Cognitive Assessment (MoCA). Results: After a year, 806 participants’ cognitive performance were maintained or slightly improved (t(805) =30.92, p < .001), while 608 participants’ performance declined (t(607) = -35.60, p < .001). Logistic regression revealed that a one point increase in GDS score was associated with an increase in the odds of cognitive decline for 1.05 (95%CI, 1.01 to 1.09), Wald χ2(1) = 5.68, p < .05, after controlling for age, gender, and education. In addition, after controlling for age, gender, education, and baseline GDS score, on a specific twoitem analysis, if participants reported awareness of relative memory deficits yet reported no emotional concern, the odds for this group to experience cognitive decline was 1.69 (95% CI, 1.24 to 2.29) times that of those who reported no relative memory deficits and/or indicated concerns (Wald χ2(1) = 11.20, p < .01). Conclusion: In general, the depressive symptoms captured by the GDS score contributes to the estimation of overall risk of cognitive decline within a 12 months period. Specifically, we have identified a two-item combination that can identify those who are significantly at higher risk of cognitive decline. Those who reported relative memory deficits, as fact, in the GDS, combined with the absence of subjective worry on deficits of memory/cognitive performance are of particular concern, irrespective of the GDS score. Our results add evidence to the clinical use of GDS as a screening tool of cognitive decline, and demonstrate the independent predictive value of cognitive and emotional awareness of memory deficits on cognitive decline.