Physiological and physical concomitants of caregiving: Introduction to special issue

One of the most noble human attributes is the willingness and desire to care for impaired loved ones. Archeological data suggest that informal caregiving has been practiced since prehistoric times. During the hunting and gathering era, some clan members survived long after they sustained injuries (1), suggesting that they could not have met the overwhelming demands of stone age life without caregivers. Although informal caregivers have always provided a service to society, their place in the modem world is paramount. With numerous advances in medical technology, the number of Americans who are becoming old-old (80+ years) is greater than ever. And, although old age does not cause disease, it is related to several illnesses (2). One such illness is Alzheimer's disease (AD). AD is a progressive degenerative brain disease that is increasing rapidly in countries whose populations have long life expectancies (Switzerland, Scandinavia, North America). Currently there are 4 million victims of AD in the United States, and it is expected that by the year 2010 there will be 11 million such victims (3). Over time, persons with AD are less able to care for themselves, becoming more dependent on their caregivers. Long before death, many AD victims become so impaired that although they are technically alive, they are not able to perform very basic activities of daily living. Vitaliano, Dougherty, and Siegler (4) have delineated several reasons why caregivers are important to victims of AD and other dementias. These include the following: (a) they (particularly spouses) come from an age cohort whose population is increasing rapidly and is at increased risk of illness (5); (b) their stress is chronic and enduring (AD can last 15 years); (c) caregiver spouses are particularly vulnerable because they lose their AD spouses' companionship and this may exacerbate their physical/ emotional problems; (d) the combination of loss, prolonged distress, and biological vulnerabilities may compromise the physiological functioning of some caregivers and increase their risk of subsequent health problems; (e) caregiver physical illnesses are associated with their decisions to institutionalize their care recipients (6); and (f) by caring for AD victims, caregivers save society billions of dollars per year (3). These events beg the question: If informal caregivers become ill, who will care for them and their care recipients? Clearly, we must identify those caregivers who are at increased risk for illness. This special issue reports research findings that focus on associations of caregiving with physiological and/or physical impairment. With some exceptions, the focus is on older caregivers (primarily spouses) who are caring for AD victims. There are at least two rationales for such research. The first is preventative--if