Depressive symptoms-Not a predictor for five-year mortality in patients with subjective cognitive decline, non-amnestic and amnestic mild cognitive impairment.

Abstract

The main aim of the present study is to evaluate the influence of depressive symptoms on mortality in patients with SCD (subjective cognitive decline), naMCI (non-amnestic mild cognitive impairment), and aMCI (amnestic mild cognitive impairment). Additional factors (age, sex, years of school attendance, and neuropsychological performance) were considered to determine the impact on survival probability. A monocentric retrospective data analysis based on adjusted patient protocols (n = 1221) from the observation period 1998-2021, using the Cox Proportional Hazards model, assessed whether depressivity had an explanatory value for survival, considering SCD as the reference level in relation to naMCI and aMCI. Covariates were included blockwise. Cox regression revealed that depressiveness (Beck Depression Inventory, Geriatric Depression Scale) did not make a significant contribution as a risk factor for mortality in all five model blocks, BDI-II with HR 0.997 [0.978; 1.02] and GDS-15 with HR 1.03 [0.98; 1.08]. Increasing age with HR 1.09 [1.07; 1.11] and male sex with HR (inverted) 1.53 [1.17; 2.00] appeared as risk factors for increased mortality across all five model blocks. aMCI (vs. SCD) with HR 1.91 [1.33; 2.76] showed a significant explanatory value only up to the fourth model block. By adding the six dimensions of the Neuropsychological Test Battery Vienna in the fifth model block, the domains attention and perceptual speed with HR 1.34 [1.18; 1.53], and executive functions with HR 1.24 [1.11; 1.39], showed substantial explanatory values for survival. Accordingly, no tendency can be attributed to depressiveness as a risk factor on the probability of survival, whereas the influence of certain cognitive dimensions, especially attention and perceptual speed, and executive functions, can be seen as protective for survival.