Depressive symptoms predict decline in perceptual speed in older adulthood

Abstract

Depressive symptoms and cognitive decline are associated in older age, but research is inconsistent about whether one condition influences the development of the other. We examined the directionality of relations between depressive symptoms and perceptual speed using bivariate dual change score models. Assessments of depressive symptoms and perceptual speed were completed by 1,206 nondemented older adults at baseline, and after 2, 8, 11, and 15 years. After controlling for age, education, baseline general cognitive ability, and self-reported health, allowing depressive symptoms to predict subsequent change in perceptual speed provided the best fit. More depressive symptoms predicted subsequently stronger declines in perceptual speed over time lags of 1 year.

1

Graphical representation of a two-variable Dual Change Score Model (DCSM(McArdle & Hamagami, 2001)) for a system of two variables X and Y. Observed (manifest) variables are represented by squares, unobserved (latent) variables by circles, regression weights by one-headed arrows, variances and covariances by two-headed arrows, and the triangle represents a constant indicating means and intercepts. All unlabeled paths are set to 1.

2

Graphical illustration of the differential magnitude of the coupling parameters and their effects over time. Model-implied means from the full coupling model were varied by half a standard deviation for one variable while the other was kept constant. Panel A shows change in depressive symptoms based on different initial perceptual speed scores. Panel B shows change in perceptual speed based on different initial depressive symptoms. Under the assumption of comparable perceptual speed performance at T1, Panel B shows that participants with few initial depressive symptoms (–0.5 SD T1 Dep) showed relatively shallow perceptual speed decline, whereas those with more depressive symptoms initially (+0.5 SD T1 Dep) showed relatively steep perceptual speed decline subsequently. In contrast, Panel A shows that depressive symptoms trajectories of change over time were minimally changed as a function of different initial levels of perceptual speed performance at T1.

2

Graphical illustration of the differential magnitude of the coupling parameters and their effects over time. Model-implied means from the full coupling model were varied by half a standard deviation for one variable while the other was kept constant. Panel A shows change in depressive symptoms based on different initial perceptual speed scores. Panel B shows change in perceptual speed based on different initial depressive symptoms. Under the assumption of comparable perceptual speed performance at T1, Panel B shows that participants with few initial depressive symptoms (–0.5 SD T1 Dep) showed relatively shallow perceptual speed decline, whereas those with more depressive symptoms initially (+0.5 SD T1 Dep) showed relatively steep perceptual speed decline subsequently. In contrast, Panel A shows that depressive symptoms trajectories of change over time were minimally changed as a function of different initial levels of perceptual speed performance at T1.