


Longitudinal Relationship of Cognitive Functioning with Depressive Symptoms in Older Adults Archana Jajodia, Ph.D. University of Southern California
Collaborators • Archana Jajodia (first author) • Andrew Revell • John J. McArdle • Lesley A. Ross • Milton Strauss • Vonetta Dotson
Aims • Examine rates of change of symptoms of depression in older adults over time • Examine rates of change of cognitive decline in executive functioning and memory • Examine longitudinal relationship of symptoms of depression with cognitive decline in executive functioning and memory
Background • Depression is related to cognitive decline in older adults • Executive functioning and memory • Longitudinal evidence is less conclusive • Direction of effects is not well-established • Cognitive decline preceding depression has not been explored • Delineating temporal relationships between cognitive functioning and depression may be key to identify mechanisms
Hypotheses • Executive functioning and memory will decline with age and depression will increase • Greater depression will be associated with • lower memory and executive functioning • greater decline in memory and executive functioning with age • Lower executive functioning will predict subsequent increase in depression • Higher depression will predict subsequent decline in memory
Measures • Data from 15 time points • Executive functioning • Fluency: animals, vegetables, fruits • Digit span backwards • Alphabet span • Number comparisons • Memory • East Boston story: immediate, delayed recall • Word list learning: immediate, delayed, recognition • Depressive Symptoms • CES-D (10 items)
Analytic Plan • Univariate latent change models for • Depressive symptoms • Memory • Executive functioning • Bivariate dynamic change models for • Memory and depressive symptoms • Executive functioning and depressive symptoms
Building the Dynamic Latent Difference Score Model (McArdle et al., 2001) • Step1. Modeling Latent Change Dx1 Dx14 x1 x2 x15 X1 X2 X15 … ex ex ex eX1 eX2 eX15
Step 2. Adding Slope and Intercept (Constant Change over Time Model) 1 mx1 ax xslope ax Dx1 Dx14 sx1 mx0 xslope* x1 x2 x15 rx0,x1 xinter X1 X2 X15 sx0 … xinter* ex ex ex eX1 eX2 eX15
Step 3. Adding Proportional Change and Covariates (Dual Change over Time Model) 1 mx1 ax xslope ax Dx1 Dx14 sx1 bx bx bx mx0 xslope* x1 x2 x15 rx0,x1 xinter X1 X2 X15 sx0 … xinter* ex ex ex eX1 eX2 eX15 Covariates
Covariates Repeat for other Variable eY1 eY2 eY15 ey ey ey yinter* sy0 Y1 Y2 Y15 … yinter ry0,y1 y1 y2 y15 my0 yslope* by by by sy1 Dy1 Dy14 ay yslope ay my1 1
Covariates Bivariate Model eY1 eY2 eY15 ey ey ey yinter* sy0 Y1 Y2 Y15 … yinter ry0,y1 ry0,x1 y1 y2 y15 my0 yslope* by by by sy1 Dy1 Dy14 ay rx1,y1 yslope ay my1 1 rx0,y0 rx,y mx1 ax xslope ax Dx1 Dx14 sx1 bx bx bx mx0 xslope* x1 x2 x15 rx0,y1 rx0,x1 xinter X1 X2 X15 sx0 … xinter* ex ex ex eX1 eX2 eX15 Covariates
Covariates eY1 eY2] eY4 ey ey ey yinter* sy0 Y1 Y2 Y5 … yinter ry0,y1 ry0,x1 y1 y2 y5 my0 yslope* by by by sy1 Dy1 Dy4 ay rx1,y1 yslope ay gxy gxy gxy my1 1 rx0,y0 rx,y mx1 gyx gyx gyx ax xslope ax Dx1 Dx4 sx1 bx bx bx mx0 xslope* x1 x2 x5 rx0,y1 rx0,x1 xinter X1 X2 X5 sx0 … xinter* ex ex ex Adding Cross loadings eX1 eX2 eX5 Covariates
Results with Memory and Depressive Symptoms • Proportional change (βs): • Memoryt ΔMemoryt+1 = 0 • CESDt ΔCESDt+1 = 0.11 symptoms (11% increase, p-value = 0.001) • Cross-loadings (γs): • Memoryt ΔCESDt+1 = 0.013 symptoms/unit score • p-value = 0.007 • CESDt ΔMemoryt+1 = -1.5 units/ symptom • p-value = 0.00007 • Model Fit: • χ2 (552) = 1,215 • RMSEA = 0.033
Results with Executive Functioning and Depressive Symptoms • Proportional change (βs): • ExecFnt ΔExecFnt+1 = 0.07 (7% increase, p-value = 0.0000007) • CESDt ΔCESDt+1 = -0.12 symptoms (12% decrease, p-value = 0.004) • Cross-loadings: • ExecFnt ΔCESDt+1 = -0.10 symptoms/unit score • p-value = 0.0000006 • CESDt ΔExecFnt+1 = ns • Model Fit: • χ2 (552) = 1,227 • RMSEA = 0.033
Results with Executive Functioning and Depressive Symptoms: Covariates
Summary of Results • More depressive symptoms associated with poorer memory and executive functioning • Not with decline in cognition • Executive functioning leads to changes in depressive symptoms over time • Depressive symptoms lead to changes in memory over time
Questions & Further Work • Cognitive measures – ok to use composites? • Distinguishing late onset and early onset depression? • Integrate history of major depression in models