433486 te and TremontJournal of Applied Gerontology
JAG32610.1177/0733464811433486Springa
Brief Report
Caregiver Burden and Depression in Mild Cognitive Impairment
Journal of Applied Gerontology 32(6) 765–775 © The Author(s) 2011 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0733464811433486 jag.sagepub.com
Beth Springate1 and Geoffrey Tremont2
Abstract Little is known about contributors to burden and depression in caregivers of patients with mild cognitive impairment (MCI) even though these patients experience cognitive, emotional, and behavioral changes. We examined caregiver burden and depression in 43 caregivers for patients with MCI as well as their associations with patients’ neuropsychological status and behavioral symptoms. Almost 30% of caregivers reported clinically significant burden, whereas 20), only functional impairment emerged as a significant predictor of burden. Unfortunately, only 17% of patients had an MCI diagnosis, limiting the applicability of these findings to the MCI population. In a retrospective chart review of 51 MCI patients, more than 30% of caregivers reported clinically significant burden (Bruce, McQuiggan, Williams, Westervelt, & Tremont, 2008). Increased caregiver burden was associated with a longer course of cognitive symptoms, patient reports of worse depression and greater cognitive difficulties, and caregiver reports of increased patient behavior, mood, and memory
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problems. Burden was not associated with patients’ cognition. However, this study did not include measures of caregivers’ emotional well-being (e.g., depression) and also did not examine the specific types of behavioral problems contributing to increased caregiver burden. The purpose of this study was to cross-validate the findings of MCI caregiver burden in a new sample and examine different predictors of caregiver burden. We sought to explore the relationships between caregiver burden and depression in MCI and examine the associations with patients’ neuropsychological status and specific behavioral symptoms.
Method Participants This retrospective review included 43 patients (32 female) referred for a neuropsychological evaluation and diagnosed with amnestic or amnestic-plus MCI consistent with Petersen’s criteria (Petersen, 2004). All patients scored >1.5 standard deviations (SD) below the population mean on at least 1 neuropsychological test, although most were impaired on at least 1 additional measure. Patients were excluded if they had a history of traumatic brain injury, stroke, severe psychiatric illness, other neurological illnesses (e.g., seizure), drug/alcohol abuse, or developmental disability. All patients brought caregivers to the evaluation who participated in the clinical interview and completed questionnaires measuring their mood and perceived burden as well as patients’ functional impairment and behavioral problems. Caregiver reports were primarily completed by patients’ spouses (n = 24) and adult children (n = 16), with the remaining 3 caregivers identifying as friends or other family members. Sixty-five percent of caregivers were female, and 63% lived with the patient. This study was approved by the institutional review board.
Measures Patient cognition. All participants completed a comprehensive neuropsychological evaluation assessing multiple domains which was administered according to standardized procedures. Composite indices for each domain were created by combining z scores based on the sample mean and standard deviation. Attention was measured with the Trail Making Test Part A (Reitan, 1958) and Digit Span forward subtest from the Wechsler Adult Intelligence Scales–III (Wechsler, 1997). The executive function domain was composed of the Trail Making Test Part B (Reitan, 1958) and the Controlled Oral Word Association (COWA) Test (Benton & Hamsher, 1989). Language was measured with the Boston Naming Test (Kaplan,
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Goodglass, & Weintraub, 1983) and Animal Fluency Test (Goodglass & Kaplan, 1983). Visuospatial skills were assessed with the Judgment of Line Orientation (Benton, Hamsher, Varney, & Spreen, 1983) and the Rey-Osterrieth Complex Figure Copy (Stern et al., 1999). The learning domain was composed of Hopkins Verbal Learning Test–Revised (HVLT-R; Brandt & Benedict, 2001) and Brief Visuospatial Memory Test–Revised (BVMT-R; Benedict, 1997) total learning scores. Delayed recall was assessed with the HVLT-R and BVMT-R delayed recall scores. For all indices, higher z scores indicate better performance. Patient depression. The Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996) measured patients’ depressive symptoms. This 21-item self-report questionnaire measures affective, cognitive, and vegetative symptoms of depression, with greater scores indicating higher levels of depression. High internal consistency (α = .86) was observed in a sample of older adults (Segal, Coolidge, Cahill, & O’Riley, 2008). Patient behavioral disturbance. Frontal systems behavior change was measured with the Frontal Systems Behavior Scale (FrSBe; Grace & Malloy, 2001). This 46-item scale is completed by the caregiver and measures behaviors associated with frontal systems dysfunction. The measure yields three subscale scores, apathy, disinhibition, and executive dysfunction, as well as a total score. Strong internal consistency has been observed for the 3 subscales in both healthy and neurological samples (α = .78-.91; Grace & Malloy, 2001). Patient activities of daily living (ADLs). Caregivers completed the Lawton-Brody Activities of Daily Living Questionnaire (Lawton & Brody, 1969), which measures patients’ degree of independence in basic (e.g., grooming, eating) and instrumental (e.g., medication and financial management) ADLs. Higher scores reflect greater functional independence. Good correlations have been demonstrated between the Lawton-Brody scale and other ADL measures (Lawton & Brody, 1969). Caregiver burden. The 22-item Zarit Burden Interview (ZBI; Zarit, Reever, & Bach-Peterson, 1980), a self-report measure of perceived burden, assessed caregiver burden. Higher scores indicate higher levels of burden. High internal consistency (α = .92) was shown in a sample of informal dementia caregivers participating in the Canadian Study of Health and Aging (Herbert, Bravo, & Preville, 2000). Caregiver depression. The Center for Epidemiologic Studies Depression Scale (CES-D; Radloff, 1977) measured caregivers’ depressive symptoms. This 20-item self-report measure assesses the extent to which caregivers experienced various symptoms of depression during the past week. Higher scores indicate higher levels of depression. Good sensitivity and specificity using a cutoff score of 16, as
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well as high internal consistency (α = .82), have been demonstrated in a sample of older adults (Lewinson, Seeley, Roberts, & Allen, 1997).
Statistical Analyses Nonparametric Spearman correlational analyses examined relationships between caregivers’ perceived burden and mood and patients’ neuropsychological composite scores, frontal systems behavioral problems, and ADLs. Forward stepwise linear multiple regressions identified significant predictors of caregiver burden and depression. For each outcome variable, all bivariate significant predictors were candidates to enter the multiple regression equation. A candidate predictor variable could enter and remain in the multivariate equation if the p value associated with its multivariate regression coefficient was ≤.05. Analyses were performed using SPSS 12.0 [Statistical Package for the Social Sciences (SPSS), 2003].
Results Demographic and clinical information can be found in Tables 1 and 2. Of the caregivers, 27.9% reported clinically significant burden (ZBI ≥ 21). Caregiver burden was not associated with patient age, gender, or education and was also not related to caregiver age or gender. No relationship between caregiver burden and whether patients lived with their caregiver or independently was observed. In contrast to almost 30% of caregivers reporting significant burden, only 2 caregivers reported clinically significant depression (CES-D ≥ 16). Caregiver depressive symptoms were positively correlated with patient age (r = .33, p < .05) but were not associated with patient gender or education, caregiver age or gender, or whether the caregiver was living with the patient. As expected, burden was positively correlated with caregiver depressive symptoms (r = .37, p < .05). Increased caregiver burden was also associated with caregiver report of increased patient frontal systems behavioral problems, including apathy (r = .46, p < .01), disinhibition (r = .44, p < .01), and executive dysfunction (r = .42, p < .01). However, no significant relationships were found between caregiver burden and patients’ neuropsychological or functional status or between caregiver burden and patient report of increased depressive symptoms. Caregiver depressive symptoms were inversely correlated with patients’ instrumental ADLs (r = –.35, p < .05), with caregivers reporting higher levels of depressive symptoms as patients’ functional abilities declined. Increases in patients’ disinhibited behaviors were also associated with increased caregiver depressive symptoms (r = .32, p < .05). Caregiver depressive symptoms were not
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Table 1. Demographic Characteristics.
Patient age Patient education Caregiver age Caregiver education ZBI CESD FrSBe Apathy Disinhibition Executive dysfunction Total Lawton-Brody Basic ADLs Instrumental ADLs Total
M
SD
Range
75.86 13.21 63.33 14.86 16.00 6.44
6.27 3.36 13.25 2.33 10.06 6.07
65-89 7-20 42-88 12-20 2-38 0-27
28.72 21.12 37.47 87.30
8.14 6.40 11.05 22.99
16-44 14-37 17-63 50-136
11.68 13.78 25.46
0.61 2.54 2.99
10-12 7-16 17-28
Note: ZBI = Zarit Burden Interview; CESD = Center for Epidemiological Studies Depression Scale; FrSBe = Frontal Systems Behavior Scale; ADL = activities of daily living. N = 43.
Table 2. MCI Patients’ Neuropsychological Test Results.
MMSE WAIS-III Digit Span Forward Trail Making Test A (sec) Trail Making Test B (sec) COWAT Boston Naming Test Animal fluency ROCF copy JOLO HVLT-R total learning BVMT-R total learning HVLT-R delayed recall BVMT-R delayed recall
M
SD
Range
26.07 8.74 52.21 201.24 29.98 44.51 11.81 14.89 10.00 14.79 7.60 2.02 2.05
2.27 1.84 24.40 82.65 10.56 8.84 4.61 2.82 2.78 3.81 2.99 2.38 1.57
20-30 5-13 19-136 62-301 12-53 18-58 5-24 9-19 5-15 6-20 2-14 0-7 0-5
Note: MMSE = Mini Mental State Examination; WAIS-III = Wechsler Adult Intelligence Scale, 3rd edition; COWAT = Controlled Oral Word Association Test; ROCF = Rey-Osterrieth Complex Figure; HVLT-R = Hopkins Verbal Learning Test–Revised; BVMT-R = Brief Visuospatial Memory Test–Revised. N = 43.
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associated with patients’ cognition, apathetic or dysexecutive behavioral problems, or depressive symptoms. Because caregiver burden was significantly correlated with caregiver depression and the three FrSBe subscales, the stepwise regression analysis performed for burden used these four variables as candidate predictors. At an entry level of p < .05, only FrSBe disinhibition (β = .51, p = .001) entered the regression equation; model fit: R2 = .26, F(1, 40) = 13.72, p = .001. Given that caregiver depression was significantly correlated with patients’ instrumental ADLs, patients’ disinhibited behaviors, and caregiver burden, these variables were entered into the stepwise multiple linear regression. Results show that instrumental ADLs (β = –.36, p < .05) and FrSBe disinhibition (β = –.30, p < .05) entered the regression equation; model fit: R2 = .26, F(2, 37) = 6.44, p < .01.
Discussion Findings confirm the presence of burden in caregivers of patients with MCI, with almost 30% of caregivers in this sample reporting clinically significant burden. This is very consistent with previous findings in different samples of MCI patients (Bruce et al., 2008). Patients’ level of disinhibition emerged as the only unique predictor of caregiver burden, and caregiver depressive symptoms were uniquely predicted by patients’ disinhibited behaviors and instrumental ADL impairments. Interestingly, degree of cognitive impairment was not correlated with caregiver burden or depressive symptoms. Furthermore, in line with previous research in MCI populations, caregiver burden was not associated with either patient or caregiver demographic characteristics. When considering the specific types of frontal system behaviors which contribute to caregiver burden in the MCI population, findings suggest disinhibition was uniquely predictive of burden, whereas apathy and dysexecutive behaviors were not. Although the contributions of different types of behavioral disturbances to caregiver burden in MCI populations have not been examined, similar relationships have been found in dementia populations. Rymer et al. (2002) found disinhibited behaviors were more strongly associated with caregiver burden than apathy or dysexecutive symptoms in a sample of AD patients and their caregivers. Similarly, Davis and Tremont (2007) found a relationship between caregiver burden and both disinhibited and dysexecutive behaviors after controlling for dementia severity and caregiver depression. Taken together, these findings suggest disinhibited behaviors may be more difficult for caregivers to manage and may form a key point for intervention. In addition, although caregiver burden and depression were correlated, findings suggest these are not interchangeable constructs. Although almost 30% of
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caregivers reported clinically significant burden, less than 5% of caregivers reported clinically significant depression and only one of these individuals reported significant caregiving burden. Furthermore, neither caregiver burden nor depressive symptoms emerged as unique predictors of the other in regression analyses. Caregivers not only reported increased burden and depressive symptoms as patients became more disinhibited but also reported increasing depressive symptoms as patients required more assistance with higher level ADLs such as financial and medication management, suggesting that caregivers’ mood may decline as they are required to provide more assistance with daily activities. This study is limited by its cross-sectional nature, limiting any inferences about causality that could be answered through longitudinal designs. Research from dementia populations suggests that patients’ awareness of their cognitive and functional impairments may serve as important predictors of caregiver burden (Rymer et al., 2002; Seltzer, Vasterling, Yoder, & Thompson, 1997), and future studies may benefit from inclusion of awareness measures. In addition, patient depression was based on self-report. As some evidence exists to suggest some MCI patients may not be reliable self-reporters (Ready, Ott, & Grace, 2006), use of informant-rated measures of patients’ mood in future studies may be beneficial. Studies that include more caregivers with clinical depression, as well as comparisons to caregivers for other substantial illnesses (e.g., cancer), may also be informative. Overall, findings from this study demonstrate the contributions of patients’ functional status and disinhibited behaviors to caregiver burden and depression. Results suggest interventions to alleviate caregiver burden and depression are important in the predementia stages, and these caregivers would benefit by addressing both practical methods to provide assistance with ADLs as well as behavioral methods to address inappropriate behaviors in patients.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References Adams, K. B., Smyth, K. A., & McClendon, M. J. (2005). Psychosocial resources as moderators of the impact of spousal dementia caregiving on depression. Journal of Applied Gerontology, 24, 475-489.
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Baumgarten, M., Battista, R. N., Infante-Rivard, C., Hanley, J. A., Becker, R., & Gauthier, S. (1992). The psychological and physical health of family members caring for an elderly person with dementia. Journal of Clinical Epidemiology, 45(1), 61-70. Beck, A., Steer, R., & Brown, G. (1996). Manual for the Beck Depression Inventory– II. San Antonio, TX: Psychological Corporation. Benedict, R. H. B. (1997). Brief Visuospatial Memory Test–Revised: Professional manual. Lutz, FL: Psychological Assessment Resources. Benton, A., & Hamsher, K. (1989). Multilingual aphasia examination. Lutz, FL: Psychological Assessment Resources. Benton, A. L., Hamsher, K. de S., Varney, N. R., & Spreen, O. (1983). Contributions to neuropsychological assessment: A clinical manual. New York, NY: Oxford University Press. Blieszner, R., & Roberto, K. A. (2009). Care partner responses to the onset of mild cognitive impairment. Gerontologist, 50(1), 11-22. Brandt, J., & Benedict, R. H. B. (2001). Hopkins Verbal Learning Test–Revised: Professional manual. Lutz, FL: Psychological Assessment Resources. Bruce, J. M., McQuiggan, M., Williams, V., Westervelt, H., & Tremont, G. (2008). Burden among spousal and child caregivers of patients with mild cognitive impairment. Dementia and Geriatric Cognitive Disorders, 25, 385-390. Davis, J. D., & Tremont, G. (2007). Impact of frontal systems behavioral functioning in dementia on caregiver burden. Journal of Neuropsychiatry and Clinical Neuroscience, 19(1), 43-49. Gallagher, D., Ni Mhaolain, A., Crosby, L., Ryan, D., Lacey, L., Coen, R. F., . . . Lawlor, B. A. (2011). Dependence and caregiver burden in Alzheimer’s disease and mild cognitive impairment. American Journal of Alzheimer’s Disease and Other Dementias, 26(2), 110-114. Garand, L., Dew, M. A., Eazor, L. R., DeKosky, S. T., & Reynolds, C. F. (2005). Caregiving burden and psychiatric morbidity in spouses of persons with mild cognitive impairment. International Journal of Geriatric Psychiatry, 20, 512-522. Goodglass, H., & Kaplan, E. F. (1983). The assessment of aphasia and related disorders (2nd ed.). Philadelphia, PA: Lea and Febiger. Grace, J., & Malloy, P. (2001). Frontal Systems Behavior Scale (FrSBe): Professional manual. Lutz, FL: Psychological Assessment Resources. Herbert, R., Bravo, G., & Preville, M. (2000). Reliability, validity, and reference values of the Zarit Burden interview for assessing informal caregivers of community-dwelling older persons with dementia. Canadian Journal on Aging, 19, 494-507. Kaplan, E. F., Goodglass, H., & Weintraub, S. (1983). The Boston Naming Test. Philadelphia, PA: Lea and Febiger.
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Lawton, M., & Brody, E. (1969). Assessment of older people: Self-maintaining and instrumental activities of daily living. The Gerontologist, 9, 179-186. Lewinson, P. M., Seeley, J. R., Roberts, R. E., & Allen, N. B. (1997). Center for Epidemiologic Studies Depression Scale (CES-D) as a screening instrument for depression among community-residing older adults. Psychology and Aging, 12, 277-287. Lu, Y.-F. Y., Austrom, M. G., Perkins, S. M., Bakas, T., Farlow, M. R., He, F., . . . Gamst, A. (2007). Depressed mood in informal caregivers of individuals with mild cognitive impairment. American Journal of Alzheimer’s Disease and Other Dementias, 22, 273-285. Mohamed, S., Rosenheck, R., Lyketsos, K., & Schneider, L. S. (2010). Caregiver burden in Alzheimer disease: Cross-sectional and longitudinal patient correlates. American Journal of Geriatric Psychiatry, 18, 917-927. Petersen, R. C. (2004). Mild cognitive impairment as a diagnostic entity. Journal of Internal Medicine, 256, 183-194. Radloff, L. S. (1977). The CESD Scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1, 385-401. Ready, R. E., Ott, B. R., & Grace, J. (2006). Insight and cognitive impairment. American Journal of Alzheimer’s Disease and Other Dementias, 21, 242-248. Reitan, R. (1958). Validity of the Trail Making Test as an indicator of organic brain damage. Perceptual Motor Skills, 8, 271-276. Rymer, S., Salloway, S., Norton, L., Malloy, P., Correia, S., & Monast, D. (2002). Impaired awareness, behavior disturbance, and caregiver burden in Alzheimer disease. Alzheimer Disease and Associated Disorders, 16, 248-253. Schulz, R., & Beach, S. R. (1999). Caregiving as a risk factor for mortality. JAMA: The Journal of the American Medical Association, 282, 2215-2219. Segal, D. L., Coolidge, F. L., Cahill, B. S., & O’Riley, A. A. (2008). Psychometric properties of the Beck Depression Inventory–II (BDI-II) among communitydwelling older adults. Behavior Modification, 32(1), 3-20. Seltzer, B., Vasterling, J. J., Yoder, J. A., & Thompson, K. A. (1997). Awareness of deficit in Alzheimer’s disease: Relation to caregiver burden. The Gerontologist, 37(1), 20-24. Sorensen, S., Duberstein, P., Gill, D., & Pinquart, M. (2006). Dementia care: Mental health effects, intervention strategies, and clinical implications. Lancet Neurology, 5, 961-973. Statistical Package for the Social Sciences(SPSS; 2003). [computer software].IBM Corporation. Stern, R. A., Javorsky, D. J., Singer, E. A., Singer Harris, N. G., Somerville, J. A., Duke, L. M., . . . Kaplan, E. (1999). The Boston Qualitative Scoring System: Professional manual. Lutz, FL: Psychological Assessment Resources.
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Stevenson, J. (1990). Family stress related to home care of Alzheimer’s disease patients and implications for support. Journal of Neuroscience Nursing, 22(3), 179-188. Wechsler, D. (1997). Wechsler Adult Intelligence Scales–III. San Antonio, TX: The Psychological Corporation. Zarit, S. H., Reever, K. E., & Bach-Peterson, J. (1980). Relatives of the impaired elderly: Correlates of feelings of burden. The Gerontologist, 20, 649-655.
Author Biographies Beth Springate, PhD (clinical psychology/neuropsychology, University of Connecticut), is a postdoctoral fellow in neuropsychology at Rhode Island Hospital and the Alpert Medical School of Brown University. Her research interests include awareness of cognitive decline in dementia, dementia caregiving, and the cognitive effects of cerebrovascular disease. Geoffrey Tremont, PhD (clinical psychology/neuropsychology, Nova Southeastern University), is an associate professor of psychiatry and human behavior at the Alpert Medical School of Brown University and director of neuropsychology at Rhode Island Hospital. His research interests include assessment methods and interventions for individuals with dementia and their caregivers.
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JAG32610.1177/0733464811433486Springa
Brief Report
Caregiver Burden and Depression in Mild Cognitive Impairment
Journal of Applied Gerontology 32(6) 765–775 © The Author(s) 2011 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0733464811433486 jag.sagepub.com
Beth Springate1 and Geoffrey Tremont2
Abstract Little is known about contributors to burden and depression in caregivers of patients with mild cognitive impairment (MCI) even though these patients experience cognitive, emotional, and behavioral changes. We examined caregiver burden and depression in 43 caregivers for patients with MCI as well as their associations with patients’ neuropsychological status and behavioral symptoms. Almost 30% of caregivers reported clinically significant burden, whereas 20), only functional impairment emerged as a significant predictor of burden. Unfortunately, only 17% of patients had an MCI diagnosis, limiting the applicability of these findings to the MCI population. In a retrospective chart review of 51 MCI patients, more than 30% of caregivers reported clinically significant burden (Bruce, McQuiggan, Williams, Westervelt, & Tremont, 2008). Increased caregiver burden was associated with a longer course of cognitive symptoms, patient reports of worse depression and greater cognitive difficulties, and caregiver reports of increased patient behavior, mood, and memory
Downloaded from jag.sagepub.com at UNIV OF UTAH SALT LAKE CITY on March 9, 2015
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problems. Burden was not associated with patients’ cognition. However, this study did not include measures of caregivers’ emotional well-being (e.g., depression) and also did not examine the specific types of behavioral problems contributing to increased caregiver burden. The purpose of this study was to cross-validate the findings of MCI caregiver burden in a new sample and examine different predictors of caregiver burden. We sought to explore the relationships between caregiver burden and depression in MCI and examine the associations with patients’ neuropsychological status and specific behavioral symptoms.
Method Participants This retrospective review included 43 patients (32 female) referred for a neuropsychological evaluation and diagnosed with amnestic or amnestic-plus MCI consistent with Petersen’s criteria (Petersen, 2004). All patients scored >1.5 standard deviations (SD) below the population mean on at least 1 neuropsychological test, although most were impaired on at least 1 additional measure. Patients were excluded if they had a history of traumatic brain injury, stroke, severe psychiatric illness, other neurological illnesses (e.g., seizure), drug/alcohol abuse, or developmental disability. All patients brought caregivers to the evaluation who participated in the clinical interview and completed questionnaires measuring their mood and perceived burden as well as patients’ functional impairment and behavioral problems. Caregiver reports were primarily completed by patients’ spouses (n = 24) and adult children (n = 16), with the remaining 3 caregivers identifying as friends or other family members. Sixty-five percent of caregivers were female, and 63% lived with the patient. This study was approved by the institutional review board.
Measures Patient cognition. All participants completed a comprehensive neuropsychological evaluation assessing multiple domains which was administered according to standardized procedures. Composite indices for each domain were created by combining z scores based on the sample mean and standard deviation. Attention was measured with the Trail Making Test Part A (Reitan, 1958) and Digit Span forward subtest from the Wechsler Adult Intelligence Scales–III (Wechsler, 1997). The executive function domain was composed of the Trail Making Test Part B (Reitan, 1958) and the Controlled Oral Word Association (COWA) Test (Benton & Hamsher, 1989). Language was measured with the Boston Naming Test (Kaplan,
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Goodglass, & Weintraub, 1983) and Animal Fluency Test (Goodglass & Kaplan, 1983). Visuospatial skills were assessed with the Judgment of Line Orientation (Benton, Hamsher, Varney, & Spreen, 1983) and the Rey-Osterrieth Complex Figure Copy (Stern et al., 1999). The learning domain was composed of Hopkins Verbal Learning Test–Revised (HVLT-R; Brandt & Benedict, 2001) and Brief Visuospatial Memory Test–Revised (BVMT-R; Benedict, 1997) total learning scores. Delayed recall was assessed with the HVLT-R and BVMT-R delayed recall scores. For all indices, higher z scores indicate better performance. Patient depression. The Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996) measured patients’ depressive symptoms. This 21-item self-report questionnaire measures affective, cognitive, and vegetative symptoms of depression, with greater scores indicating higher levels of depression. High internal consistency (α = .86) was observed in a sample of older adults (Segal, Coolidge, Cahill, & O’Riley, 2008). Patient behavioral disturbance. Frontal systems behavior change was measured with the Frontal Systems Behavior Scale (FrSBe; Grace & Malloy, 2001). This 46-item scale is completed by the caregiver and measures behaviors associated with frontal systems dysfunction. The measure yields three subscale scores, apathy, disinhibition, and executive dysfunction, as well as a total score. Strong internal consistency has been observed for the 3 subscales in both healthy and neurological samples (α = .78-.91; Grace & Malloy, 2001). Patient activities of daily living (ADLs). Caregivers completed the Lawton-Brody Activities of Daily Living Questionnaire (Lawton & Brody, 1969), which measures patients’ degree of independence in basic (e.g., grooming, eating) and instrumental (e.g., medication and financial management) ADLs. Higher scores reflect greater functional independence. Good correlations have been demonstrated between the Lawton-Brody scale and other ADL measures (Lawton & Brody, 1969). Caregiver burden. The 22-item Zarit Burden Interview (ZBI; Zarit, Reever, & Bach-Peterson, 1980), a self-report measure of perceived burden, assessed caregiver burden. Higher scores indicate higher levels of burden. High internal consistency (α = .92) was shown in a sample of informal dementia caregivers participating in the Canadian Study of Health and Aging (Herbert, Bravo, & Preville, 2000). Caregiver depression. The Center for Epidemiologic Studies Depression Scale (CES-D; Radloff, 1977) measured caregivers’ depressive symptoms. This 20-item self-report measure assesses the extent to which caregivers experienced various symptoms of depression during the past week. Higher scores indicate higher levels of depression. Good sensitivity and specificity using a cutoff score of 16, as
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well as high internal consistency (α = .82), have been demonstrated in a sample of older adults (Lewinson, Seeley, Roberts, & Allen, 1997).
Statistical Analyses Nonparametric Spearman correlational analyses examined relationships between caregivers’ perceived burden and mood and patients’ neuropsychological composite scores, frontal systems behavioral problems, and ADLs. Forward stepwise linear multiple regressions identified significant predictors of caregiver burden and depression. For each outcome variable, all bivariate significant predictors were candidates to enter the multiple regression equation. A candidate predictor variable could enter and remain in the multivariate equation if the p value associated with its multivariate regression coefficient was ≤.05. Analyses were performed using SPSS 12.0 [Statistical Package for the Social Sciences (SPSS), 2003].
Results Demographic and clinical information can be found in Tables 1 and 2. Of the caregivers, 27.9% reported clinically significant burden (ZBI ≥ 21). Caregiver burden was not associated with patient age, gender, or education and was also not related to caregiver age or gender. No relationship between caregiver burden and whether patients lived with their caregiver or independently was observed. In contrast to almost 30% of caregivers reporting significant burden, only 2 caregivers reported clinically significant depression (CES-D ≥ 16). Caregiver depressive symptoms were positively correlated with patient age (r = .33, p < .05) but were not associated with patient gender or education, caregiver age or gender, or whether the caregiver was living with the patient. As expected, burden was positively correlated with caregiver depressive symptoms (r = .37, p < .05). Increased caregiver burden was also associated with caregiver report of increased patient frontal systems behavioral problems, including apathy (r = .46, p < .01), disinhibition (r = .44, p < .01), and executive dysfunction (r = .42, p < .01). However, no significant relationships were found between caregiver burden and patients’ neuropsychological or functional status or between caregiver burden and patient report of increased depressive symptoms. Caregiver depressive symptoms were inversely correlated with patients’ instrumental ADLs (r = –.35, p < .05), with caregivers reporting higher levels of depressive symptoms as patients’ functional abilities declined. Increases in patients’ disinhibited behaviors were also associated with increased caregiver depressive symptoms (r = .32, p < .05). Caregiver depressive symptoms were not
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Table 1. Demographic Characteristics.
Patient age Patient education Caregiver age Caregiver education ZBI CESD FrSBe Apathy Disinhibition Executive dysfunction Total Lawton-Brody Basic ADLs Instrumental ADLs Total
M
SD
Range
75.86 13.21 63.33 14.86 16.00 6.44
6.27 3.36 13.25 2.33 10.06 6.07
65-89 7-20 42-88 12-20 2-38 0-27
28.72 21.12 37.47 87.30
8.14 6.40 11.05 22.99
16-44 14-37 17-63 50-136
11.68 13.78 25.46
0.61 2.54 2.99
10-12 7-16 17-28
Note: ZBI = Zarit Burden Interview; CESD = Center for Epidemiological Studies Depression Scale; FrSBe = Frontal Systems Behavior Scale; ADL = activities of daily living. N = 43.
Table 2. MCI Patients’ Neuropsychological Test Results.
MMSE WAIS-III Digit Span Forward Trail Making Test A (sec) Trail Making Test B (sec) COWAT Boston Naming Test Animal fluency ROCF copy JOLO HVLT-R total learning BVMT-R total learning HVLT-R delayed recall BVMT-R delayed recall
M
SD
Range
26.07 8.74 52.21 201.24 29.98 44.51 11.81 14.89 10.00 14.79 7.60 2.02 2.05
2.27 1.84 24.40 82.65 10.56 8.84 4.61 2.82 2.78 3.81 2.99 2.38 1.57
20-30 5-13 19-136 62-301 12-53 18-58 5-24 9-19 5-15 6-20 2-14 0-7 0-5
Note: MMSE = Mini Mental State Examination; WAIS-III = Wechsler Adult Intelligence Scale, 3rd edition; COWAT = Controlled Oral Word Association Test; ROCF = Rey-Osterrieth Complex Figure; HVLT-R = Hopkins Verbal Learning Test–Revised; BVMT-R = Brief Visuospatial Memory Test–Revised. N = 43.
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associated with patients’ cognition, apathetic or dysexecutive behavioral problems, or depressive symptoms. Because caregiver burden was significantly correlated with caregiver depression and the three FrSBe subscales, the stepwise regression analysis performed for burden used these four variables as candidate predictors. At an entry level of p < .05, only FrSBe disinhibition (β = .51, p = .001) entered the regression equation; model fit: R2 = .26, F(1, 40) = 13.72, p = .001. Given that caregiver depression was significantly correlated with patients’ instrumental ADLs, patients’ disinhibited behaviors, and caregiver burden, these variables were entered into the stepwise multiple linear regression. Results show that instrumental ADLs (β = –.36, p < .05) and FrSBe disinhibition (β = –.30, p < .05) entered the regression equation; model fit: R2 = .26, F(2, 37) = 6.44, p < .01.
Discussion Findings confirm the presence of burden in caregivers of patients with MCI, with almost 30% of caregivers in this sample reporting clinically significant burden. This is very consistent with previous findings in different samples of MCI patients (Bruce et al., 2008). Patients’ level of disinhibition emerged as the only unique predictor of caregiver burden, and caregiver depressive symptoms were uniquely predicted by patients’ disinhibited behaviors and instrumental ADL impairments. Interestingly, degree of cognitive impairment was not correlated with caregiver burden or depressive symptoms. Furthermore, in line with previous research in MCI populations, caregiver burden was not associated with either patient or caregiver demographic characteristics. When considering the specific types of frontal system behaviors which contribute to caregiver burden in the MCI population, findings suggest disinhibition was uniquely predictive of burden, whereas apathy and dysexecutive behaviors were not. Although the contributions of different types of behavioral disturbances to caregiver burden in MCI populations have not been examined, similar relationships have been found in dementia populations. Rymer et al. (2002) found disinhibited behaviors were more strongly associated with caregiver burden than apathy or dysexecutive symptoms in a sample of AD patients and their caregivers. Similarly, Davis and Tremont (2007) found a relationship between caregiver burden and both disinhibited and dysexecutive behaviors after controlling for dementia severity and caregiver depression. Taken together, these findings suggest disinhibited behaviors may be more difficult for caregivers to manage and may form a key point for intervention. In addition, although caregiver burden and depression were correlated, findings suggest these are not interchangeable constructs. Although almost 30% of
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caregivers reported clinically significant burden, less than 5% of caregivers reported clinically significant depression and only one of these individuals reported significant caregiving burden. Furthermore, neither caregiver burden nor depressive symptoms emerged as unique predictors of the other in regression analyses. Caregivers not only reported increased burden and depressive symptoms as patients became more disinhibited but also reported increasing depressive symptoms as patients required more assistance with higher level ADLs such as financial and medication management, suggesting that caregivers’ mood may decline as they are required to provide more assistance with daily activities. This study is limited by its cross-sectional nature, limiting any inferences about causality that could be answered through longitudinal designs. Research from dementia populations suggests that patients’ awareness of their cognitive and functional impairments may serve as important predictors of caregiver burden (Rymer et al., 2002; Seltzer, Vasterling, Yoder, & Thompson, 1997), and future studies may benefit from inclusion of awareness measures. In addition, patient depression was based on self-report. As some evidence exists to suggest some MCI patients may not be reliable self-reporters (Ready, Ott, & Grace, 2006), use of informant-rated measures of patients’ mood in future studies may be beneficial. Studies that include more caregivers with clinical depression, as well as comparisons to caregivers for other substantial illnesses (e.g., cancer), may also be informative. Overall, findings from this study demonstrate the contributions of patients’ functional status and disinhibited behaviors to caregiver burden and depression. Results suggest interventions to alleviate caregiver burden and depression are important in the predementia stages, and these caregivers would benefit by addressing both practical methods to provide assistance with ADLs as well as behavioral methods to address inappropriate behaviors in patients.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
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Author Biographies Beth Springate, PhD (clinical psychology/neuropsychology, University of Connecticut), is a postdoctoral fellow in neuropsychology at Rhode Island Hospital and the Alpert Medical School of Brown University. Her research interests include awareness of cognitive decline in dementia, dementia caregiving, and the cognitive effects of cerebrovascular disease. Geoffrey Tremont, PhD (clinical psychology/neuropsychology, Nova Southeastern University), is an associate professor of psychiatry and human behavior at the Alpert Medical School of Brown University and director of neuropsychology at Rhode Island Hospital. His research interests include assessment methods and interventions for individuals with dementia and their caregivers.
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