Informal Caregivers of Persons with Dementia: The Relationship between Sleep Patterns and

Depression

Rita F. D’Aoust, PhD, ANP-BC

University of South Florida College of Nursing

rdaoust@health.usf.edu

Meredeth A. Rowe, PhD, RN

University of South Florida College of Nursing

Scope of the problem

• Currently, 5.4 million Americans live with Alzheimer’s

disease

• 1 out of 8 (13%) over 65; 1 out of 2 (50%) over 85 have AD• By 2050, the number AD cases is expected to triple due to

the effect of 78.2 million baby boomers who began turning 65

• More than half of persons with AD live at home.• Almost 75 percent of home care is given by family and

friends by more than 15 million unpaid informal caregivers who provide 17.4 billion hour of unpaid care, an estimated value of $210 billion

Significance/importance of the problem

• Caring for a PWD is often demanding and can have serious negative health consequences for the caregiver (CG) with depression being one of the most common to occur (Covinsky, Newcomer et al. 2003; Vitaliano, Zhang et al. 2003).

• Many studies have shown that CGs high levels of depressive symptoms (DS) and clinical depression as compared to non-caregivers (Joling, Van Hout, et al., 2010; Epstein-Lubow, Davis, Miller, & Tremont; 2008; Schoenmakers, Buntinx, &

Deleleleire, 2010; Schultz & Martire, 2004; Joling, Smit et al. 2012). • The incidence of depression in spousal dementia caregivers has been

estimated to be four times higher than in spouses with a cognitively intact partner (Joling, Van Hout et al. 2010)

• Depression and high levels of DS have important potential adverse physiologic consequences for caregivers including CVD, metabolic syndrome, functional decline, and earlier incidence of mortality

• Depressed CGs are more likely to abandon the caregiver role often resulting in formal care

Literature: Fixed Factors • Several studies identify a number of predictors and variables

associated with DS or depression in CGs (Joling et al., 2010, Takahashi et al., 2005; Martire & Hall, 2002; Covinski et al., 2003; Zank & Frank, 2002)

– Gender, age, race/ethnicity, education, relationship, pre-caregiving health status, caregiver burden and role strain

– Care recipient factors include severity of dementia, behavioral symptoms for dementia, depression, and ADL assistance

• Notable finding is that many of the factors studied are not amenable to change

• Desire to focus on amenable to change/intervention and to determine if any of these factors are associated with DS in CGs

Literature: Amenable Factors - Sleep

Sleep • Poor sleep is a predictor of future depression, worse depression,

and more treatment failures (Buysse, 2004, Berk, 2009)

• More sleep complaints & poor sleep in CGs than non-CGs (McCurry, Longsdon, et al., 2007)

• primarily self-report• low sleep efficiency, longer time to fall asleep, poor sleep quality,

and more wake time after falling asleep (McCurry et al., 2007; Beaudreau et al., 2008)

• Some evidence of a relationship between poor sleep and DS (McCurry et al., 2009)

– DS CGs 2.5x more likely to have sleep problems

• Poor sleep and DS both associated with CVD and metabolic syndrome

Literature: Amenable Factors - Affect

• Positive affect (PA) and negative affect (NA) are two independent dimensions of affect/mood (Watson et al., 1999)

• Low levels PA and high levels NA Both offer unique prediction to DS and clinical depression (Watson et al., 1999; Crawford et al., 2004)

• High levels PA and low levels NA may buffer CGs from distress of caregiving (Mausbach et al., 2011)

• CGs have high levels NA including anxiety and worry and these may be associated with DS (Mahoney, 2003)

Literature: Amenable Factors – Respite Care and Social Support

• Provision of respite care and social support are linked to greater well being (Atienza et al., 2001; Cohen et al., 1986)

• CGs with greater levels of support have lower risk for depression (Atienza et al., 2001; Thompson et al., 1993)

Purpose of Research

The purpose of this study was to identify amenable factors that contribute to caregiver depression while considering typical fixed depression-associated factors.

The specific aims of this study are to determine:1. Determine the impact of sleep, negative affect and caregiving

support  on caregiver depression.

2. Determine whether that impact remains after accounting for demographic and clinical factors commonly associated with depression in caregivers.

Methods: Design & Sample

• Secondary data analysis• Informal caregivers providing direct care to a person with

dementia were recruited (n=54)• Data were taken from 7-day baseline of a study designed to

test effectiveness of a nighttime activity monitor system in improving dementia caregivers' sleep• Demographic, clinical, and questionnaire data were collected on Day 1, and

subjective/objective sleep data collection began that night for 7 nights

Methods - MeasuresOutcome Variable:• Depressive Symptomology (DS): Center for Epidemiologic Studies

Depression scale (CES-D)

Amendable Factors:• Objective Sleep: Actigraphy• Subjective Sleep: Sleep diary• Daytime sleepiness: Epworth Sleepiness Scale (ESS)• Daily Mood: Positive Affect and Negative Affect Scale (PANAS) • CG antidepressant medication use• Other support for caregiving duties• Desire to Institutionalize (DIS)

Fixed Factors:• Demographic Characteristics: Gender, race/ethnicity, spousal CG,

employment, CG health• Caregiving burden: Zarit Caregiving Burden Interview (CBI)

Methods - Analyses

• SPSS 20• Descriptive and frequency

statistics• Bivariate correlations• Regression analysis

Results: Descriptive

Fixed Factors:– Caregivers were predominantly white, female, and spouses

of the care recipients – Age - 38 to 86 years; mean = 63. – Higher levels of education

• all at least a high school education and 30% having a college degree

Depression

• A small percentage of CGs (14.8%) reported the use of antidepressant medications but the CES-D scores did not differ based on reported drug use

(t = -.79, p=.43).

Results: Descriptive – Amendable Factors

Sleep Objective:– 8.3% of the caregivers received at least 7 hours of sleep, – 75% of the sample reported they had more than 30 minutes of WASO, – none of the caregivers were found to have greater than 85% SE

Sleep Subjective:– 29.8% reported >7 hours sleep, – 38.5% of the caregivers were found to have SE>85%, – 42.3% thought they had <30 minutes of WASO

Daytime Sleepiness:– ESS mean = 8.17, almost twice the general population (4.4-4.6)– 25% of caregivers’ -score of 10 in which further evaluation of daytime

sleepiness is recommended.

Results: Descriptive – Daily Mood

CGs average score for PA (13.29) compares to the 26th percentile for the general population.

Results: Bivariate Analyses

• Only 1 fixed factor was significantly association with DS. High levels burden and high DS

• Only 3 modifiable variables were significantly correlated with higher DS: high levels of subjective WASO, high levels of NA and low levels of subjective SQ.

  Caregiver

Burden

Subjective

WASO

Subjective

SQ

Negative

Affect

Depressive

Symptoms

(CES-D)

.62***

p<.001

.27*

p=.09

-.34**

p=.03

.58***

P<.001

*p<.10, **p<.05, ***p<.001

Results: Backward Regression Analyses

Model A (Question 1):

NA, subjective SQ, and subjective WASO on DS

• R2 = 23.7% (F (df = 1,49)=30.51, p <.001)– NA

Model B (Question 2):

CBI, NA, subjective SQ, and subjective WASO on DS

• R2 = 52.6% (F=15.17 (df = 4, 47), p<0.001)– caregiver burden and NA

Discussion: Question 1 - Impact of sleep, NA, CG Support on DS

• These CGs had very high levels of NA and very low levels of PA consistent with the tripartite model of depression (Clark & Watson, 1991).

• There was a strong relationship between NA and burden (r – 0.48, <p. 001). CGs with high level burden may have emotional exhaustion which may lead to low levels of PA.

• Recent evidence examining the relationship of NA, PA, and DS suggests that the modulating influence of PA (Mausbach et al., 2011)

• The relationship of sleep and depression in this sample of dementia caregivers differs from the general population.

Discussion - Sleep

• The only sleep variable that was significantly related to depression was subjective WASO, but that relationship lost significance when burden was entered into the model.

• Examined concept of WASO misperceptions to further understand this relationship– WASO-SD > WASO-Actigraphy

WASO Misperception

Conclusions

• Caregivers should be evaluated regularly and formally for depressive symptoms.

• Identifying targets that are amenable to intervention is difficult in this population with only negative affect being significantly related to depression.

• Interventions to increase positive mood and reduce negative mood should be developed for dementia caregivers, particularly for caregivers with high levels of DS.