Alexandrea L. Harmell

Meta-Analysis of the Association Between Cognitive Abilities and Everyday Functioning in Bipolar Disorder

Depp CA, Mausbach BT, Harmell AL, Savla GN, Bowie CR, Harvey PD, Patterson TL. Meta‐analysis of the association between cognitive abilities and everyday functioning in bipolar disorder. Bipolar Disord 2012: 14: 217–226.

A Review of the Psychobiology of Dementia Caregiving: A Focus on Resilience Factors

The recent aging trend in the United States has resulted in exponential growth in the number of informal dementia caregivers. Caring for a family member with dementia has been associated with negative health outcomes that are likely related to physiologic changes resulting from stress. However, caregiving is not always associated with health morbidity. In this review, we highlight resilience factors that appear to have a beneficial relationship with health outcomes. Specifically, we highlight 11 studies that examined the relationship of one of three broad resilience domains (personal mastery, self-efficacy, and coping style) to caregiver health outcomes. Our main findings were that higher levels of personal mastery and self-efficacy, and increased use of positive coping strategies appear to have a protective effect on various health outcomes in dementia caregivers. Continued research is warranted to help guide prospective directions for caregiver interventions focusing on increasing caregiver resilience and the corresponding impact on caregiver health.

Effects of Alzheimer caregiving on allostatic load.

This study aimed to determine if Alzheimer caregivers have increased allostatic load compared to non-caregivers. Potential psychological moderators (mastery, depression, and role overload) of the relationship between caregiving status and allostatic load were also explored. Eighty-seven caregivers and 43 non-caregivers underwent biological assessment of allostatic load and psychological assessments. Caregivers had significantly higher allostatic load compared to non-caregivers ( p < .05). Mastery, but not depression or overload, moderated the relationship between caregiving status and allostatic load. In conclusion, allostatic load may represent a link explaining how stress translates to downstream pathology, but more work is necessary to understand the role of psychological factors.

Multiple mediators of the relations between caregiving stress and depressive symptoms

Objective: This study tested a model for explaining how stress is associated with depressive symptoms in a sample of spouse caregivers of patients with Alzheimers disease. It was hypothesized that more depressive symptoms would be significantly correlated with both ‘primary’ caregiver stressors (i.e., care recipient problem behaviors) and ‘secondary’ stress (i.e., role overload), but that this relationship would be significantly mediated by four variables: (1) personal mastery, (2) coping self-efficacy, (3) activity restriction, and (4) avoidance coping. Method: We used an asymptotic and resampling strategy for simultaneously testing multiple mediators of the stress-to-depressive symptoms pathway. Results: Greater stress was significantly related to more depressive symptoms. Increased stress was also associated with reduced personal mastery and self-efficacy, as well as increased activity restriction and avoidance coping. Finally, these four mediators accounted for a significant amount of the relationship between stress and depressive symptoms. Discussion: These results suggest multiple pathways by which both primary and secondary caregiver stresses may be associated with increased depressive symptoms, and may argue for multiple treatment targets for caregiver interventions.

Interactive effects of vascular risk burden and advanced age on cerebral blood flow

Vascular risk factors and cerebral blood flow (CBF) reduction have been linked to increased risk of cognitive impairment and Alzheimers disease (AD); however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs) previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors), advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor). This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus), inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus), and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus) cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.

Relationship between chronic stress and carotid intima-media thickness (IMT) in elderly Alzheimer's disease caregivers

The stress associated with providing care for a spouse diagnosed with Alzheimers disease can have adverse effects on cardiovascular health. One potential explanation is that chronic caregiving stress may contribute to the development of atherosclerosis. The purpose of this study was to determine whether the duration that one has provided care is associated with the degree of atherosclerotic burden, as measured by carotid artery intima-media thickness (IMT). One hundred and ten Alzheimer caregivers [mean age 74 ± 8 (SD) years, 69% female] underwent in-home assessment of carotid artery IMT via B-mode ultrasonography. Data regarding medical history, blood pressure, and multiple indicators of caregiving stress were also collected. Multiple regression indicated that duration of care was positively associated with IMT measured in the internal/bifurcation segments of the carotid artery (β = 0.202, p = 0.044) independent of risk factors such as age, gender, body mass index, smoking history, sleep quality, hypertension status, and caregiving stressors. Duration of care was positively associated with IMT in the common carotid artery, but the relationship was not significant. These findings provide more evidence of the link between chronic caregiving stress and cardiovascular disease and indicate that enduring the experience of caregiving over a period of years might be associated with atherosclerotic burden.

REGULAR PHYSICAL ACTIVITY MODERATES CARDIOMETABOLIC RISK IN ALZHEIMER'S CAREGIVERS

INTRODUCTION Dementia caregivers have an increased risk of cardiovascular disease, and it is possible that metabolic disturbances contribute to this risk. Regular physical exercise reduces cardiometabolic risk, but caregivers may have less opportunity to engage in such activity. We hypothesized that regular physical activity would moderate cardiometabolic risk in dementia caregivers. METHODS One hundred and fifteen Alzheimers caregivers and 54 noncaregiving controls were assessed for medical history and health habits. Physical activity was defined as the number of days per week participants performed light (score = 0-4), moderate (score = 0-4), or vigorous (score = 0-4) exercise (total score = 0-12). A cardiometabolic risk score was calculated by adding standardized z-scores of five metabolic syndrome components: body mass index, triglycerides, HDL cholesterol, systolic blood pressure, and glucose. RESULTS Caregivers were less physically active than noncaregivers (mean ± SD = 5.1 ± 3.0 vs 6.3 ± 2.7, P = 0.008). A significant caregiver status × physical activity interaction was found for the standardized cardiometabolic risk score controlling for gender, age, education, smoking, alcohol consumption, health problems, cholesterol-lowering medication, negative affect, role overload, and fasting state (P = 0.035). Among participants with low levels of physical activity, caregivers had greater cardiometabolic risk score than noncaregivers (0.58 ± 0.31 vs -1.23 ± 0.54, P = 0.017); no group difference emerged in participants with high levels of physical activity (P = 0.81). CONCLUSIONS Cardiometabolic risk was particularly high in caregivers reporting reduced levels of regular physical activity. Intervention studies aimed at increasing physical activity in caregivers seem warranted to examine whether that would possibly lower cardiometabolic risk to the level of noncaregivers.

The moderating role of personal mastery on the relationship between caregiving status and multiple dimensions of fatigue

A substantial proportion of chronically‐stressed spousal dementia caregivers report fatigue. The objective of this study was to examine whether personal mastery moderates the relationship between caregiving status (caregiver/non‐caregiver) and multiple dimensions of fatigue.

Influence of Caregiver Burden on the Association Between Daily Fluctuations in Pleasant Activities and Mood: A Daily Diary Analysis

Much research has focused on behavioral activation and its effect on depression, but less is known about the effects of leisure activities on the two distinct affective domains of depression: positive affect (PA) and negative affect (NA). Furthermore, individual factors (i.e., stress level) may moderate the impact of behavioral activation on affect. The present study utilized a daily diary approach to examine the moderating effect of stress on the relationship between leisure satisfaction and both PA and NA. Twenty-five dementia caregivers completed activity and affect measures four times daily for 14 days. Results were analyzed using multilevel modeling, an approach that considers intra-individual differences in activity and affect over time. Results supported the hypothesis that caregivers with higher burden display a stronger association between leisure satisfaction and affect than caregivers with lower burden. Specifically, caregivers with higher burden had a stronger positive relationship between leisure satisfaction and PA and a stronger negative relationship between leisure satisfaction and NA. These findings suggest that screening caregivers for level of burden may help identify those most likely to benefit from behavioral interventions.

The relationship between self-efficacy and resting blood pressure in spousal Alzheimer's caregivers.

OBJECTIVE To examine whether high levels of self-efficacy for problem-focused coping were significantly related to several resting BP measures in spousal Alzheimers disease caregivers. DESIGN Cross-sectional. METHODS Participants included 100 older caregivers (mean age = 73.8 ± 8.14 years) providing in home care for a spouse with Alzheimers disease. All participants completed a 13-item short form of the Coping Self-Efficacy Scale and underwent an in-home assessment where a visiting nurse took the average of three serial BP readings. Multiple regression was used to examine the relationship between self-efficacy and mean arterial pressure (MAP), systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) after controlling for age, gender, smoking history, body mass index, the care recipients clinical dementia rating, diabetes, alcohol use, and the use of antihypertensive medications. RESULTS Overall, high levels of self-efficacy for problem-focused coping were associated with lower MAP, SBP, and PP. Self-efficacy for problem-focused coping was marginally associated with resting DBP, but not significant. In addition, we conducted secondary analyses of the other two self-efficacy scales to explore the relationship between each dimension and MAP. We found that there were no significant relationships found between MAP and self-efficacy for stopping unpleasant thoughts/emotions or self-efficacy for getting social support. CONCLUSIONS The present study adds to the current body of literature by illustrating the possibility that higher self-efficacy can have physiological advantages, perhaps by buffering chronic stresss impact on resting BP. Another contribution of the current study is its attempt to understand the role of each individual component of self-efficacy. These findings invite future research to investigate whether caregivers might experience cardiovascular benefits from interventions aimed at enhancing self-efficacy.