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

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Step 3. Adding Proportional Change and Covariates (Dual Change over Time Model)

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Bivariate Model

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Adding Cross loadings

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 Memory and Depressive Symptoms

Correlations CESD-intercept

CESD-slope Memory-intercept

CESD-slope -0.97

Memory-intercept

-0.11 ns

Memory-slope

0.97 -0.98 ns

Results with Memory and Depressive Symptoms: CovariatesRegression Weights

CESD-intercept

CESD-slope Mem-intercept

Mem-slope

Age at baseline

0.17 ns -0.42 0.13

Female ns ns 0.15 ns

Education ns ns 0.18 ns

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 SymptomsCorrelations CESD-

interceptCESD-slope ExecFn-

intercept

CESD-slope ns

ExecFn-intercept

-0.14 0.33

ExecFn-slope

ns ns -0.39

Results with Executive Functioning and Depressive Symptoms: CovariatesRegression Weights

CESD-intercept

CESD-slope ExecFn-intercept

ExecFn-slope

Age at baseline

0.16 -0.23 -0.43 ns

Female ns ns 0.14 ns

Education ns ns 0.21 -0.24

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