Caregivers may face years of continuous exposure to physical and psychosocial demands with burdens that can include physical, psychological, social, and financial problems; embarrassment; overload; and resentment.
Family caregivers provide unpaid assistance to care recipients who have difficulty with daily functioning because of physical, cognitive, or emotional impairment. Although caregiving varies with a recipient's problems, it usually involves helping with maintenance and/or higher-level activities. Caregivers of persons with dementia and Parkinson disease (PD) absorb a great deal of the indirect costs (eg, lost wages, in-home support) of these diseases. In 1991, the total US direct medical cost of Alzheimer disease (AD) was $20 billion ($12,700 per patient per year plus $1454 for diagnoses in the first year).1 Unfortunately, the costs to caregivers are not only economic but also psychosocial and physical.
We focus here on the stressors and reactions of caregivers of persons with dementia and related disorders. We also consider caregivers who are at high risk for problems and how psychiatrists can help them and their care recipients.
Caregiver stressors and outcomes
Many caregivers face 3 to 15 years of continuous exposure to physical and psychosocial demands. As AD progresses, caregivers must continually monitor the care recipient, cope with difficult behaviors, and witness the deterioration of the recipient.2 Caregiving may be a dress rehearsal for bereavement because it can involve prolonged grief, and bereavement is associated with several negative sequelae, including higher mortality rates.3
Caregiver burden can include physical, psychological, social, and financial problems4; embarrassment; overload; and resentment.5 Across all stages of dementia, feelings of lost control and/or communication on the part of the caregiver are the best predictors of perceived burden.6 Caregiver responses vary with their relationship to the recipient. Spouses are at risk because of their own physical frailties and loss of support.7 Alternatively, caring for a spouse may be viewed as a marriage commitment, but caring for a parent may produce conflicts with a spouse and/or children.8
A meta-analysis of 84 articles found that caregivers had higher levels of depression, perceived stress, and lower levels of self-efficacy than noncaregivers.9 Differences were related to study quality, relationship of caregiver to recipient, and caregiver demographics. Psychiatric morbidity in caregivers varies with sample type. Neundorfer10 found that 25% of the caregivers who were randomly selected from an AD registry had clinical depression.
Gallagher and associates11 found that 36% of caregivers who were not seeking help had clinical depression, compared with 68% of self-referred caregivers. Russo and associates12 found that a diagnosis of current major depression disorder had been made within the past month for 7% of caregivers versus 1% of demographically similar noncaregivers. Depression varied from 11% to 37%13,14 in caregivers of stroke victims and from 2% to 4% in community dwelling older adults.15
Recent research has continued to elucidate connections between chronic stress and the immune system. A metaanalysis of 23 studies of 1594 caregivers of persons with dementia and 1478 demographically similar noncaregivers found that caregivers had a 15% lower level of antibody responses (poorer IgG responses to vaccines, high levels of herpes simplex virus antibodies in absence of a challenge) and a 23% higher level of stress hormones (eg, cortisol) than noncaregivers.16
Because antibody responses to vaccination are lower in older adults, older caregivers may be at higher risk for influenza; and chronically elevated epinephrine and cortisol levels may lead to increased risk of hypertension and diabetes. Caregivers who experience chronic stress may be at risk for cognitive problems as well.17 Such problems may have a negative impact on self-care, their ability to be caregivers, the information they provide about care recipients, and their responses to cognitive therapies.
There have been 3 prospective studies that used case-control comparisons of noncaregivers with caregivers. In one study, caregivers providing the most assistance had the greatest risk for at least one negative health outcome relative to other caregivers and noncaregivers over 1 to 6 years.18 In another study, caregivers reporting distress had a 63% higher death rate than noncaregivers over 4 years.19 Yet another study found that the higher incidence of coronary disease in caregivers than in noncaregivers was explained by the anger, distress, health habits, and metabolic syndrome levels of the caregivers.20 Unfortunately, these studies could not assess whether persons who become caregivers are at greater risk for negative outcomes prior to and independent of caregiving.
Caregiving and preexisting illness
Russo and associates12 found that 73% of caregivers with a history of diagnosed depression had recurrent depression while caregiving, but only 30% of noncaregivers with such a history had a recurrence during a similar time. Caregivers with recurrent depression are at added risk for medical illnesses, because depression increases the risk for heart disease21 and diabetes.22 Medical illnesses may interact with caregiving and exacerbate physiologic risk.
A history of cancer may predispose one to immunologic risk.23 Caregivers with cancer histories have lower natural killer cell activity (NKA) than noncaregivers with cancer histories, but NKA does not differ in individuals free of cancer histories.24 This is important because a major function of NKA is to attack tumors.
Normotensive caregivers and noncaregivers do not differ in systolic blood pressure reactivity to a laboratory stressor, but hypertensive caregivers show greater reactivity than hypertensive noncaregivers.25 Reactivity may exacerbate the effects of hypertension.26 Caregivers with coronary disease show higher levels of the metabolic syndrome than noncaregivers with coronary disease. However, no difference exists for individuals free of such disease.27
Caregivers with diabetes and/or coronary disease may be at higher risk for complications from these diseases than are noncaregivers with these diseases. This may be especially true of caregivers with heart disease or diabetes and depression. Depression is a risk factor for mortality among patients with post–myocardial infarction and patients with type 2 diabetes.28 End-organ damage secondary to ischemic heart disease or diabetes may make depressed caregivers more vulnerable to mortality.
Interventions to support caregivers
Studies have shown that interventions to support caregivers have proved beneficial to health outcomes. Interventions with active treatments reduced burden (ie, perceived psychological problems),29 and pleasant event therapies (ie, interventions that teach caregivers to identify and pursue experiences that give them pleasure on a regular basis) decreased depression.30,31 Among persons with coronary disease, higher levels of the metabolic syndrome in caregivers than noncaregivers are explained, in part, by the fact that caregivers also have lower levels of pleasant experiences than noncaregivers. Pleasant experiences are also correlated with higher NKA in caregivers with cancer histories.24
Dietary and physical activity interventions show 1-year improvements in health behaviors, depression, and sleep problems.32 In a meta-analysis, Brodaty and associates33 examined 34 interventions and found benefits in caregiver distress/knowledge that were reflected in improved care-recipient mood and delayed nursing home admission. They noted that programs may be more successful if they involve care recipients and caregivers, are more intensive, and are modified to caregivers' needs. Other investigators have found that interventions should be tailored to caregiver ethnicity,34 because ethnic groups respond differently to caregiving.35
The psychiatrist's role
Psychiatrists who treat patients with PD or AD should also monitor and help treat the caregivers of these patients, especially if the caregivers have preexisting medical conditions. Caregiver decline may be associated with decline in the patient receiving care. Reciprocal relationships between caregiver dispositions and care recipient health/functioning should be monitored and when negative feedback is observed it should be mitigated through psychiatric treatment.36 For instance, depression in a caregiver may result in poorer adherence to medical regimens in the patient, such as taking prescription medication at regular intervals. Screening and treatment of caregivers for depression may help improve their energy and concentration as well as their ability to keep the patient on medical regimens, preventing the patient's health decline.
Older caregivers with major depression or dysthymia secondary to caregiving are vulnerable to poor outcomes because they may not seek mental health treatment.37 Those that do are less likely than younger depressed individuals to receive specialty mental health services,38 and the services they do receive are usually in primary care rather than mental health specialty care.39
Such inadequacies have fostered interventions that deliver evidencebased depression care within a primary care setting.40 These programs integrate allied health/mental health professionals into primary care to provide:
Collaborative care for depressed older adults (who had a mean of 3 comorbid medical illnesses) improved quality of care and physical functioning and lowered depression compared with usual care.41 Collaborative care for patients with diabetes and depression saves medical costs, thus balancing out the mental health costs needed to improve depression.42 Because the stress associated with caregiving may exacerbate medical conditions and health risks, collaborative care models are essential for treating physical and psychiatric conditions in caregivers.
Such models should be adapted to caregivers' needs, including home visits, help with management of difficult behaviors, greater use of telephone contacts, and management of mental and physical illnesses.
Drs Vitaliano and Katon are professors in the department of psychiatry and behavioral sciences at the University of Washington in Seattle. They report that they have no conflicts of interest concerning the subject matter of this article.