Do personality traits contribute to Do personality traits contribute to resiliency to brain pathology?resiliency to brain pathology?

Sarah Tomaszewski Farias, Maritza Sarah Tomaszewski Farias, Maritza Dowling, Dan Mungas, Bruce Reed, Dowling, Dan Mungas, Bruce Reed,

Joshua Sonnen, Milton StraussJoshua Sonnen, Milton Strauss

Conceptual ApproachConceptual Approach Conceptually, reserve explains deviations from the level of Conceptually, reserve explains deviations from the level of

cognitive performance that would be expected for a given cognitive performance that would be expected for a given amount of brain pathologyamount of brain pathology

Methodological approach: we modeled reserve as residual Methodological approach: we modeled reserve as residual cognition after accounting for neuropathology (and brain cognition after accounting for neuropathology (and brain weight?) and then we examined variables that account for this weight?) and then we examined variables that account for this residualresidual

Personality trait examined: Neuroticism/distress Personality trait examined: Neuroticism/distress proneness/negative affectivity and trait anxietyproneness/negative affectivity and trait anxiety

RationaleRationale Chronic reaction to threat triggers overactivation of the HPA Chronic reaction to threat triggers overactivation of the HPA

axis and the release of stress hormones (i.e. glucocorticoids, axis and the release of stress hormones (i.e. glucocorticoids, particularly cortisol)particularly cortisol)

It is hypothesized that chronic exposure to cortisol increases It is hypothesized that chronic exposure to cortisol increases excitatory amino acid release, resulting in neuronal injuryexcitatory amino acid release, resulting in neuronal injury

The hippocampus is particularly vulnerable to such effects since The hippocampus is particularly vulnerable to such effects since it has a high density of glucocorticoid receptorsit has a high density of glucocorticoid receptors

Hippocampal atrophy has been associated with PTSD and other Hippocampal atrophy has been associated with PTSD and other chronic psychiatric syndromeschronic psychiatric syndromes

Elevated basal cortisol is associated with hippocampal atrophy Elevated basal cortisol is associated with hippocampal atrophy (in pts with AD)(in pts with AD)

Frontal systems (particularly anterior cingulate) have also been Frontal systems (particularly anterior cingulate) have also been implicatedimplicated

Cognitive factor

Residual/reserve

Npath 1 Npath 3Npath 2

Cog 1 Cog2 Cog 3 Cog4 Cog5 Cog 6

Conceptual Model

Cognitive Activity

DistressProneness

Education

Data SourcesData Sources

Rush Memory Assessment Project (MAP) and ROSRush Memory Assessment Project (MAP) and ROS Similar to previous studies presentedSimilar to previous studies presented

Distress proneness variableDistress proneness variable

Recall that Neuroticism was defined as the total score obtained in the following FIVE items (common to both ROS and MAP): Variable # Variable Name Question v2 inferior ------I often feel inferior to others v3 tense--------- I often feel tense and jittery v4 getangry -----I often get angry at the way people treat me v5 discourg------Too often, when things go wrong, I get discouraged and feel like giving up v6 helpless-------I often feel helpless and want someone else to solve my problems

Trait Anxiety VariableTrait Anxiety Variable

The trait anxiety construct included the following 10 items common to both MAP & ROS Question: For the next statements, circle Y for YES if it describes how you generally feel or N for NO if it does not describe how you generally feel. 1. I feel pleasant. 2. I feel nervous and restless 3. I wish I could be as happy as others seem to be. 4. I feel that difficulties are piling up so that I cannot overcome them. 5. I lack self-confidence. 6. I feel secure. 7. I feel inadequate. 8. I am content. 10. I take disappointments so keenly that I can t put them out of my mind. Coding: Integer 1 = Yes 2 = No 8 = REFUSAL 9 = DON'T KNOW The Reliability index (Om ega) is 0.927252

NOTE – THE CORRELATION BETWEEN NEUOTICISM & TRAIT ANXIETY IS 0.578 FIRST, I EXAMINED EFFECTS OF NEUROTICISM & ANXIETY SEPARATELY. TESTS OF MODEL FIT Chi-Square Test of Model Fit Value 1421.795* Degrees of Freedom 596 P-Value 0.0000 Scaling Correction Factor 1.028 for MLR Value 14267.244 Degrees of Freedom 726 P-Value 0.0000 CFI/TLI CFI 0.939 TLI 0.926

RMSEA (Root Mean Square Error Of Approximation) Estimate 0.046 90 Percent C.I. 0.043 0.049 Probability RMSEA <= .05 0.982 SRMR (Standardized Root Mean Square Residual) Value 0.038

Distress proneness on residualDistress proneness on residual

RES ON NEUTICNW -0.077 0.018 -4.327 0.000****

The R2 with Neuroticism as covariate is Latent Two-Tailed Variable Estimate S.E. Est./S.E. P-Value EPISR 0.738 0.038 19.304 0.000 SEMR 0.678 0.056 12.144 0.000 WMR 0.848 0.033 25.725 0.000 PSPR 0.803 0.034 23.892 0.000 PORGR 0.818 0.065 12.563 0.000 FLR 0.765 0.031 24.574 0.000 RES 0.049 0.023 2.140 0.032**

Distress proneness on residualDistress proneness on residual

Trait Anxiety on residualTrait Anxiety on residual

RES ON TRTANX2 -0.175 0.058 -3.013 0.003** The R2 with trait anxiety as a covariate is La t ent Two- Ta i l e d Var i abl e Es t i ma t e S. E. Es t . / S. E. P- Val ue EPI SR 0 . 7 39 0. 0 38 1 9. 3 64 0. 0 00 SEMR 0 . 6 79 0. 0 56 1 2. 1 57 0. 0 00 WMR 0 . 8 49 0. 0 33 2 5. 6 89 0. 0 00 PSPR 0 . 8 02 0. 0 34 2 3. 6 97 0. 0 00 PORGR 0 . 8 17 0. 0 65 1 2. 5 30 0. 0 00 FLR 0 . 7 66 0. 0 31 2 4. 6 58 0. 0 00 RES 0 . 0 31 0. 0 20 1. 5 06 0. 1 32 ns

Model with both Distress Proneness and Trait AnxietyModel with both Distress Proneness and Trait Anxiety

RES ON NEUTICNW -0.172 0.062 -2.766 0.006**** TRTANX2 -0.089 0.067 -1.322 0.186 ns R^2 La t ent Two- Ta i l e d Var i abl e Es t i ma t e S. E. Es t . / S. E. P- Val ue RES 0 . 0 55 0. 0 25 2. 2 06 0. 0 27* *

Other variables to considerOther variables to consider

We also examined social engagement and size of social We also examined social engagement and size of social network – neither alone or in a joint model accounted for network – neither alone or in a joint model accounted for significant variance in the residual term (trend of social significant variance in the residual term (trend of social engagement in individual model p = .068)engagement in individual model p = .068)

It may be possible to examine physical activity – but the It may be possible to examine physical activity – but the variable we appear to have is only ‘current’ physical activity variable we appear to have is only ‘current’ physical activity (not retrospective ratings of earlier life activity) and variable is (not retrospective ratings of earlier life activity) and variable is highly skewed highly skewed

Remaining questionsRemaining questions Previous work by the Rush group suggests that distress proneness Previous work by the Rush group suggests that distress proneness

does not relate to traditional neuropathology of aging variables does not relate to traditional neuropathology of aging variables (amyloid, tangels, LBs, infarcts) (amyloid, tangels, LBs, infarcts) – Other evidence suggests chronic distress may lead to nonspecific Other evidence suggests chronic distress may lead to nonspecific

changes such as decreased dendritic arborizationchanges such as decreased dendritic arborization– Should we look at a model that does not include brain weight (which Should we look at a model that does not include brain weight (which

may reflect these nonspecific changes)?may reflect these nonspecific changes)? Other work from the Rush group suggest that distress proneness Other work from the Rush group suggest that distress proneness

may have differential effects on different cognitive domains may have differential effects on different cognitive domains (episodic memory)(episodic memory)– Should we look separately at the residual terms for specific cognitive Should we look separately at the residual terms for specific cognitive

domains?domains?