The connection between stress and morbidity and mortality has been demonstrated in a variety of studies. Stressful life events have been shown to predict mortality in initially healthy populations (Rosengren et al., 1993) and in patients with heart disease (Ruberman et al., 1984). Specific types of stressful events are also linked to mortality and illness. In particular, job strain, bereavement, and providing care for a chronically ill relative have been predictive of all-cause mortality and heart disease (Karasek et al., 1988; Martikainen and Valkonen, 1996; Schnall et al., 1994; Schulz and Beach, 1999).
One type of stressor—caring for a spouse with Alzheimer’s disease—is especially relevant for older adults. Although caregiving can have some emotional rewards, caregivers on the whole report extraordinarily high levels of burden and stress (Schulz et al., 1995; Vitaliano et al., 1997), which may increase their mortality risk. A recent study compared 392 older people who were providing care for a spouse with a group of 400 people of the same age without this responsibility. Approximately 50 percent of the caregivers reported emotional strain associated with their caregiver roles. Over the 4-year study, those caregivers who reported mental and emotional strain were 63 percent more likely to die than the noncaregivers. Caregivers not reporting strain were not at increased risk of mortality (Schulz and Beach, 1999). There is therefore at least moderately strong evidence that stress is predictive of morbidity and mortality.
The association between stress and illness may be indirect, in that stress has been shown to influence a number of other risk factors. Stress has been associated with an increase in intravenous drug use, smoking, alcohol use, physical inactivity, and unprotected sex (Dougal and Baum, 2001; Kaplan et al., 1993). Therefore, stress may be looked at as both a potential proximal and distal cause of illness and mortality.
The Commonwealth Minority Health Survey provides a unique glimpse of racial and ethnic variation in stress (Williams, 2000). On a global measure combining exposure to stressors in five domains (occupation, finances, relationships, racial bias, and violence), blacks, Hispanics, and Asians reported higher levels of stress than whites. Among Hispanics, Puerto Ricans had the highest levels of stress. Interestingly, there was dramatic variation among the Asian subgroups included: Chinese reported higher levels of stress than any other group in the study, Vietnamese were intermediate, and Koreans reported the lowest levels in the study.
Reaction to stressors may also differ across groups. Blacks, especially those at the low end of the economic spectrum, report not only a great number of stressful life events but also stronger responses to them, or