LIFE EVENTS AND STRESS

Life events are defined as discrete experiences that disrupt an individual's usual activities, causing a substantial change and readjustment. Examples of life events include marriage, divorce, illness or injury, and changing or losing a job. In the literature on stress, life events have been traditionally considered as one type of stressor, along with chronic strains (ongoing stressful circumstances such as living with disability or poverty). Since the pioneering work of Tom Holmes and Richard Rahe in 1967, an enormous body of literature has developed on the topic of life events and illness.

Life events research

Life events research has evolved from early models viewing life changes as inherently stressful and having similar effects on all who experience them to more complex models emphasizing individual differences in both reactions and vulnerability to life events. In addition, there have been a number of conceptual and methodological critiques that have led to more sophisticated models and methods of assessing life events. Recent studies demonstrate that, even with careful attention to methodological issues, life events can have important effects on health and psychological well-being.

Historical issues. Early studies conceptualized life events in terms of the amount of readjustment or change that the events were likely to entail (see Dohrenwend and Dohrenwend; Holmes and Rahe). These studies were based on the assumption that any change in life would be stressful. Particularly influential was the work of Holmes and Rahe, who developed the Social Readjustment Rating Scale (SRRS). The SRRS asked subjects to report the occurrence of life events that had occurred over the previous year, and these events were given life-change unit scores (e.g., 100 for death of a spouse, 28 for an outstanding personal achievement). Total scores were viewed as a measure of life change and as an index of stress. While research with the SRRS did suggest that life events were associated with mental and physical health, limitations to this approach were noted in subsequent work, and conceptual and methodological improvements have been made.

Individual differences in response to life events. Contrary to the assumption that life events have uniform effects that can be measured by life-change units, later studies have shown that the consequences of life events depend on the nature of the events (e.g., whether they are undesirable, unpredictable, or uncontrollable). Growing attention has been paid to subjective meaning of the events to the particular individuals who experience them, rather than the objective occurrence of the events. Since the occurrence of the same event can yield different meanings in each individual, subjective appraisal has been identified as a critical part of the effect life events have on well-being (see Lazarus and Folkman). For example, people generally think that divorce is a stressful experience; however, for some individuals, such as those who have gone through a long-term problematic marriage, divorce can be a resolution of stress and even a relief.

The consequences of life events on physical and psychological well-being are influenced by individual differences in coping resources. When life events occur, individuals' coping resources can buffer the negative consequences of life events and facilitate adjustment. Coping resources may include physical resources (e.g., health and function), psychological resources (e.g., personality traits, values, goals, religious beliefs, self-concept, and self-control), and social resources (social network and social support). One of the most frequently researched psychological resources is mastery, which refers to the extent to when a person feels that he or she has control over his or her life and environment. Individuals with high mastery tend to have a positive perspective on the social environment and believe that they can control or alter their environment. Therefore, those with high mastery are more likely to protect themselves from negative consequences when they face stressful life events.

The impact of social networks and social support has also been widely studied, and there exists a general consensus on their beneficial roles in dealing with stressful life events. It has been found that individuals with persistent deficits in social support experience more stressful life events, higher levels of perceived stress, and greater risk of recurrent depression (see Redinbaugh, MacCallum, and Kiecolt-Glaser). An examination of individuals' personal and social resources is important in understanding individual valances in responding and adapting to stressful life events, and also serves as an important basis for developing effective intervention programs.

Types of life events. Criticisms have been raised concerning the tactic of aggregating total life events to generate an overall score. Many studies on life events have turned the total number of events into a single score by aggregating all life events experienced within a given time frame. This approach treats all events the same, without taking into account the subjectively perceived importance of each event. Since life event inventories cover a variety of events of different importance, equating those events may be insensitive in capturing the significance of different life events, and it may fail to detect the effects of specific events that generate a great deal of stress. Some researchers have suggested the use of a more dimension-specific approach, focusing on specific kinds of events by dividing scales into categories, such as health-related events and loss events.

Retrospective bias in reporting life events. Conventional life event inventories usually ask respondents to read a list of events and report those that occurred to them over a specific time period. The time frames vary from six to eighteen months. Some researchers have raised questions on the accuracy of individuals' memories for life events. In general, people tend to report fewer events for a more distant time period. In addition, a retrospective approach is vulnerable to biasing effects such as selective memory, denial, and over-reporting. For example, depressed people are likely to report more negative events because they tend to focus on the adverse sides of life and to search for events to justify their current moods.

Given this dissatisfaction with the checklist method, researchers have attempted innovative ways to assess life events. Some studies have used combined methods of self-reporting on checklists and interviews. Karen Raphael and colleagues (1991) assessed the occurrence of life events every month for ten months using a checklist, and at the end of the study they did detailed interviews on experience with life events for the studied period. They found that more events were reported on a concurrent monthly basis than were reported on a retrospective interview for the same period. As an alternative to retrospective report over long periods, some researchers have conducted multiple follow-ups for the occurrence of life events, with a very short interval between interviews, in order to detect the onset of events. This approach solves some problems associated with the retrospective report using a checklist method; however, it requires a large sample and longitudinal follow-up.

Life events are not uniform across populations. Some researchers have called into question whether scale items contain relevant and representative life events for target populations. Since scales are rarely generated on the basis of large and well-developed sampling frames, it is hard to judge if the items cover a sufficiently wide range of possible events. More importantly, exposure to life events varies in terms of age, gender, and social roles. For example, retired individuals cannot be promoted, men cannot be pregnant, and unmarried individuals cannot experience marital conflict or divorce. Inclusion of irrelevant items for the target population may result in misclassifying individuals as having fewer numbers of life events.

In response to this concern, a number of life event inventories have been developed for various populations, including the Psychiatric Epidemiological Research Interview (PERI) for general populations; the Life Experiences Survey (LES) for adult age groups; the College Student Life Events Schedule (CSLES) for college students, and the Louisville Older Persons Events Scale (LOPES) for the elderly population.

Confounding of life events and outcomes. Confounding is a particularly important issue in the examination of life events. Many items in life event inventories are closely related to health (e.g., illness, injury, hospitalization), so they can be easily confounded with physical and mental health outcomes. Due to concerns about the confounding of health and life events, some researchers recommend separating health-related life events from non-health-related items. Some studies have selected only healthy elderly individuals in examining the impacts of life events in order to exclude confounding of health variables (see Willis, Thomas, Garry, and Goodwin).

Recent findings on life events and well-being. Numerous studies have examined the consequences of life events on a variety of physical and psychological outcomes. In general populations, life events have been shown to be associated with a variety of physical problems and indicators of psychological distress. However, the magnitude of these associations is often found to be only modest. Researchers have suggested several ways to explain the low associations found in such studies, including methodological issues and individual differences in coping resources.

One fruitful strategy in the study of the effects of life events is longitudinal study of individuals with psychological or physical disorders that tend to have periods of remission and recurrence. For example, it is extremely difficult to demonstrate conclusively that life events provoke the initial onset of depressive disorders, but longitudinal research on individuals with a history of depression provides convincing evidence that life events can lead to recurrence of depressive episodes. Sophisticated longitudinal studies even support the contention that major life events play important roles in onset and recovery from episodes of bipolar disorder and multiple sclerosis—disorders that are commonly viewed as entirely biomedical. Research on life events in these clinical populations has also led to increasing recognition that some life events are caused by the disorders studied; for example, loss of a job may be precipitated by early symptoms of a mental disorder.

Finally, life events have been demonstrated to be potent factors affecting physiological processes, in particular the immune and endocrine systems, with implications for health and recovery from illness. For example, studies of individuals undergoing stressful life events ranging from taking final examinations to experiencing bereavement demonstrate a slowing of wound healing—a finding with clear implications for practical problems such as recovery from surgery.

Life events in old age

Individuals from various age groups are exposed to different sets of life events. Yet, despite potentially important age differences, relatively little research has focused on life events in later life. Research on life events in old age is of great importance, since identifying prevalent events and managing stress in later life can not only improve our understanding of human development and adaptation, but can also serve as a basis for interventions and social policies.

Age differences in the occurrence of life events. Contrary to the general belief that old age is a stressful period of time, studies have consistently shown that older adults experience fewer life events than do younger adults. However, though the overall number of events that individuals experience may decline with advancing aging, some specific types of life events are more likely to be encountered in later life. Illness and injury, hospitalization, and the death of a spouse or a friend are examples of undesirable life events that are more prevalent in old age. Using a large sample of community-dwelling older adults, Stanley Murrell and colleagues (1984) showed that over half of their sample had experienced hospitalization, either their own or that of significant others, in the past year. Of course, some other types of life events, such as family conflict and problems with jobs, are less prevalent in older adults.

Another reason for the reduction in life events in later life may be found in the composition of measurement scales. Since most life event inventories used in previous studies were originally developed and standardized on relatively young populations, items less relevant to older adults, such as getting married, having children, and changing jobs, are often included. Given the different experiences in the life cycle, some researchers have developed life event inventories for older individuals. Studies employing relevant measures for older individuals have been shown to be more successful in relating life events and measures of well-being. The LOPES is one notable measure specifically designed for older populations. This scale includes fifty-four life events, selected on the basis of a large, stratified sample of older Kentuckians, and a recall period of six months in order to ensure greater accuracy of older adults' recall. It also contains additional useful ratings of subjects such as desirability, the degree of change required, preoccupation, date of occurrence, and novelty of each event.

Age differences when responding to life events. Some events experienced by older individuals are age-normative events that are expected by most people to occur later in the life cycle. When events are anticipated, their adverse impact may be limited because individuals are prepared for them. In the case of planned retirement, older individuals fare much better than do younger persons who involuntarily lose a job. In addition, retirement may even lead to enhanced physical and psychological well-being.

On the other hand, the death of an adult child is a non-normative experience for older individuals. Even though only a small portion of the older population experiences the loss of a child, it can have a devastating influence on physical and emotional well-being of older individuals. The unexpected and untimely nature of such an event interferes with adjustment and adaptation, and can also make older adults feel guilty.

Studies show that older individuals are more likely than younger persons to be affected by the events that occur to people they are close to. Such events have been referred to as network events or nonegocentric events. Examples include adult children's marital or financial problems and illness of family members or friends. With advancing age, individuals pay more attention to the problems of others and become vulnerable to these events.

Researchers have suggested that individuals' prior experiences should be considered to better understand their experiences with life events. This is particularly true for older adults who have had various and rich experiences through the life course. A life-long experience of dealing with stress may provide a context to understand an individual's response to certain events. In many cases, older individuals tend to perceive life events as less troublesome because they are more likely to have relevant experiences to help them cope. Research that focused on older victims of a flood showed that older individuals with prior experience of floods showed less anxiety and distress than younger persons or persons without such experience (see Murrell et al., 1988). Accumulated life experiences may make older individuals more resilient and facilitate their adaptation to change. The experience of seeing others undergo life events may also aid older people in adaptation to life events. For example, the experience of spousal bereavement may be less devastating for older widows compared to younger ones, in part because widowhood of older females is more prevalent and there are many role models in society.

Along with prior experience, current life situations also provide an important context for interpreting individual differences in the impacts of life events. Life events that happen concurrently with other events or under situations of chronic strains may have different meanings than a single event. Older caregivers of dementia patients report more negative events and appraise them as more stressful than controls who are not caregivers (see Reed, Stone, and Neale). In contrast, some researchers have suggested that chronic strains may actually mute the impact of stressful events because minor stressful events pale in comparison to more chronic stressors.

Chronic strains can even change the context and outcomes of major life events. Research suggests that highly strained caregivers show some recovery of functioning after the death of a spouse, while noncaregivers react with increased depression. Since chronic strains and life events interact in a variety of ways, examination of both life events and chronic strains is helpful in understanding individuals' responses to life events.

Positive life events. Most life events research has focused on negative and undesirable life events, and the beneficial effects of positive life events need to receive more attention. Birth of grandchildren, going on a trip out of town, receiving an award or special praise, and starting a new hobby or recreational activity are some of examples of positive events that happen in later life. These positive life events not only have a desirable meaning to older individuals but also moderate the impacts of stressful events. Positive events make individuals focus on good feelings, change views of other events, and provide motivation and resources to overcome stress resulting from negative events. Research on depression in late life has shown that depressed older adults have relatively few pleasant events, and that treatments aimed at increasing pleasant events can reduce depression.

Future directions

With its long history, life events research has progressed a great deal and provided important information from both theoretical and practical perspectives. The study of life events in late life has produced promising results and findings that challenge conventional stereotypes about the vulnerability of older persons. Conceptual sophistication about aging and the life course is evident in the attention that has been paid to the different occurrence of, and reactions to, life events in later life.

However, research on life events and aging has lagged behind that of the broader field in terms of methodology. For example, few studies of life events in older adults have utilized longitudinal assessments and frequent individualized interviews to avoid problems of retrospective recall. While sophisticated methods have been developed and applied to the study of life events in psychiatric and medical disorders in younger people, little is known about how life events may trigger relapse or recurrence of these disorders In the elderly. Studies of older adults should borrow heavily from methods that have been refined in studies of younger persons.

A particular need is for more clinically relevant research on life events and aging, with the goal of promoting an empirically based practice of clinical geropsychology. Evidence to date suggests that older adults respond well to cognitive-behavioral or psychoeducational intervention programs that teach specific skills in coping with life events and chronic strains, and that research on life events provides valuable information for clinicians designing and implementing such intervention programs. However, interventions for bereavement in older adults have shown disappointing results to date, serving an example of an area in which clinicians need better research information to improve clinical practice for older adults.

Yuri Jang William E. Haley

See also Bereavement; Control, Perceived; Geriatric Psychiatry; Social Support; Stress and Coping.

BIBLIOGRAPHY

Aldwin, C. M. "The Elders Life Stress Inventory: Egocentric and Nonegocentric Stress." In Stress and Coping in Later-Life Families. Edited by M. A. P. Stephens, J. H. Crowther, S. E. Hobfoll, and D. L. Tennenbaum. New York: Hemisphere Publishing, 1990. Pages 49–69.

Avison, W. R., and Gotlib, Ian H. Stress and Mental Health: Contemporary Issues and Prospects for the Future. New York: Plenum, 1994.

Chiriboga, D. A. "The Measurement of Stress Exposure in Later Life." In Aging, Stress, and Health. Edited by K. S. Markides and C. L. Cooper. Chichester, U.K.: John Wiley & Sons, 1989. Pages 13–41.

Dohrenwend, B. S.; Askenasy, A. R.; Krasnoff, L.; and Dohrenwend, B. P. "Exemplification of a Method for Scaling Life Events: The PERI Life Events Scale." Journal of Health and Social Behavior 19 (1978): 205–229.

Dohrenwend, B. P., and Dohrenwend, Barbara S. Social Status and Psychological Disorder. New York: John Wiley, 1969.

Folkman, S.; Lazarus, R. S.; Pimley, S.; and NOvacek, J. "Age Differences in Stress and Coping Processes." Psychology and Aging 2 (1987): 171–184.

Hlastala, S. A.; Frank, E.; Kowalski, J.; Sherrill, J. T.; Tu, X. M.; Anderson, B.; and Kupfer, D. J. "Stressful Life Events, Bipolar Disorder, and the Kindling Model." Journal of Abnormal Psychology 109 (2000): 777–786.

Holmes, T. H., and Rahe, R. H. "The Social Readjustment Rating Scale." Journal of Psychosomatic Research 11 (1967): 315–328.

Kessler, R. C. "The Effects of Stressful Life Events on Depression." Annual Review of Psychology 48 (1997): 191–214.

Kiecolt-Glaser, J. K.; Page, G. G.; Marucha, P. T.; MacCallum, R. C.; and Glaser, R. "Psychological Influences on Surgical Recovery Perspectives from Psychoneuroimmunology." American Psychologist 53 (1998): 1209–1218.

Lazarus, R. S., and Folkman, S. Stress, Appraisal, and Coping. New York: Springer, 1984.

Murrell, S. A.; Norris, F. H.; and Grote, C. "Life Events in Older Adults." In Life Events in Psychological Functioning. Edited by L. H. Cohen. Newbury Park, Calif.: Sage, 1988. Pages 96–122.

Murrell, S. A.; Norris, F. H.; and Hutchins, G. L. "Distribution and Desirability of Life Events in Older Adults: Population and Policy Implications." Journal of Community Psychology 12 (1984): 304–311.

Neimeyer, R. A. "Searching for the Meaning of Meaning: Grief Therapy and the Process of Reconstruction." Death Studies 24 (2000): 541–558.

Pearlin, Leonard I., and Skaff, M. M. "Stressors and Adaptation in Later Life." In Emerging Issues in Mental Health. Edited by M. Gatz. Washington, D.C.: American Psychological Association, 1995. Pages 97–123.

Raphael, K. G.; Cloitre, M.; and Dohrenwend, Bruce P. "Problems of Recall and Misclassification with Checklist Methods of Measuring Stressful Life Events." Health Psychology 10 (1991): 62–74.

Redinbaugh, E. M.; MacCallum, R. C.; and Kiecolt-Glaser, J. K. "Recurrent Syndromal Depression in Caregivers." Psychology and Aging 10 (1995): 358–368.

Reed, Bruce R.; Stone, Arthur A.; and Neale, J. M. "Effects of Caring for a Demented Relative on Elders' Life Events and Appraisals." The Gerontologist 30 (1990): 200–205.

Sandler, I. N., and Lakey, B. "Locus of Control as a Stress Moderator: The Role of Control Perceptions and Social Support." American Journal of Community Psychology 10 (1982): 65–80.

Sarason, I. G.; Johnson, J. H.; and Siegel, J. M. "Assessing the Impacts of Life Changes: Development of the Life Experiences Survey." Journal of Consulting and Clinical Psychology 46 (1978): 932–946.

Schulz, R.; Beach, S. R.; Lind, B.; Martire, L. M.; Zdaniuk, B.; Hirsch, C.; Jackson, S.; and B., Lynda. "Involvement in Caregiving and Adjustment to Death of a Spouse: Findings from the Caregiver Health Effects Study." Journal of the American Medical Association 285 (2001): 3123–3129.

Schwartz, C. F.; Foley, F. W.; Rao, S. M.; Bernardin, L. J.; Lee, H.; and Genderson, M. W. "Stress and Course of Disease in Multiple Sclerosis." Behavioral Medicine 25 (1999): 111–116.

Willis, L.; Thomas, P.; Garry, P. J.; and Goodwin, J. S. "A Prospect Study of Response to Stressful Life Events in Initially Healthy Elders." Journal of Gerontology 42 (1987): 627–630.

Zarit, S. H., and Zarit, J. M. Mental Disorders in Older Adults: Fundamentals to Assessment and Treatment. New York: Guilford Press, 1998.