The Effect of Stress on Illness in Adulthood: Recent Research

Introduction

Most people can relate to the experience of getting sick at inopportune times, times when they have a lot to do, and they need to perform efficiently. How many times has it seemed that you have come down with a nasty cold or flu, just as your workload or stress level increased? If stress plays a role in the acquisition of minor ailments, than what is its effect on the course and acquisition of major diseases? A great deal of research has been done to determine the role of stress on the development of diseases. Recent research has found that stress can play a major role in the exacerbation or onset of symptoms of disease.

Role of Stress in Systemic Lupus Erythematosus

Adams, Dammers, Saia, Brantley, andGaydos (1994) researched the effect of perceived stress on patients of Systemic Lupus Erythematosus (SLE). Earlier research in this area found a link between a high level of reported stress and worsening of Lupus patients' condition. In fact, a very high percentage of patients actually attributed their condition's worsening to a major stressful event in their lives. These early studies however, have three major flaws (as reported by Adams et al. (1994)). "First most studies regarding psychiatric symptoms are solely descriptive in nature...Second, studies have utilized only retrospective report of major life events as a measure of stress. As noted by Zimmerman (1983), medical patients may report more stress during times of illness... Third, the use of psychometrically validated stress measures is sorely lacking... Additionally, the potential role of minor life events has been ignored." This study attempts to address each of these shortcomings. Subjects in this experiment completed surveys that assessed major life events (number and intensity), minor daily stressors (number, intensity), and symptom history. The findings of this research were that there is support for a correlation between stress and SLE intensity. Also, a relationship was shown between major stress, minor stress, and SLE symptom levels. A surprising finding was that minor life events seemed to account for most of the effect on the severity of the symptoms.

Potential Moderators of Stress Outcomes

This research was done to show that hardiness and neuroticism would be potential moderators of stress outcomes. I think this research is important not only because it is based on the findings that stress influences illness reactions, but also because it shows that different people have different reactions to environmental stress. This article discusses the relationship between stress and illness, by the model known as diathesis-stress. Diathesis refers to a proclivity for a certain illness, while stress refers to the method of response to environmental stressors. This model proposes that problems arise due to two factors: "inability to cope effectively with the level of stress experienced and a complex interaction of genetic and social psychological illness mediating variables" (Hills and Norvell 1991). This article again provided evidence that minor stressors were more important to outcomes than major stressors were. The subjects, male highway patrol troopers, reported daily hassles such as "constant shift changes, feelings of being on duty all the time, rapidly changing levels of stimulation during a single shift, and the inherent nature of the work" (Hills and Norvell 1991) as more stressful than the unreported, yet seemingly more major, stress from the possibility of death. The findings of this research show that multiple, minor factors are more damaging to an outcome than major stressors, and also that perception of stress plays an important role in the intensity of the effect of stress on the outcome. This research was done mostly to examine hardiness and neuroticism as two major continuums that would have an effect on outcomes such as: burnout. This research though, as a matter of necessity, also explains a great deal about the frequency and intensity of stressors and the role they play in outcomes, such as burnout or sickness.

Relevance of Major Stress Events in Inflammatory Bowel Disease

Previously, a great deal of research has been done investigating the effect of emotional factors on inflammatory bowel disorder. However, the impact of psychological stress in recurrence of inflammatory bowel disease (IBD) is unclear ( Duffy et al. 1991). In fact, some research failed to find stress to be a causative agent in IBD activity. In this study, inflammatory bowel disease activity and stress levels were measured at a baseline level. In monthly increments, both activity of IBD and stress level were assessed (for 6 month duration). After a month, subjects were again measured for IBD activity (by physician examination), and stress level (by completing the Schedule of Recent Experience which included events such as: job loss, divorce, and illness. This study had the philosophy that perception of minor stressors was too prone to influence from disease symptoms. For this reason, minor stressors were considered unreliable, and not measured in this study. Instead, major stress events were recorded. An interesting convention of this study is the creation of stress categories. The categories were: occupation related stress, family or marriage related stress, and health related stress (Duffy et al. 1991). Oddly enough, the only category of stress which showed a significant effect on inflammatory bowel disease was health related stress. This however, is an ambiguous category because the health stress category includes not only stresses of health-related accidents (such as getting food poisoning or burns), but also the stress created by IBD! The results of this study are that patients experiencing disease activity were more than two times as likely to be exposed to major stress events than other subjects. Also, an important finding was that events, other than health related events, did not have a significant effect on the course of inflammatory bowel disease. Finally, it was found that management of health related stress emphasized the negligible roles of occupation and family related stress. "The relationship between stress and disease activity is perhaps best described as self-perpetuating and mutually reinforcing: stress leads to active disease, which in turn provokes stress" (Duffy et al. 1991).

The Relation of Stress to Interdialytic Weight Gain

Everett, Brantley, Sletten, Jones, and McKnight (1995) investigated the effect that stress had on the extent to which hemodialysis patients stuck to their regimen of monitoring diet and fluid intake. "As a consequence of severely reduced kidney function, fluids and toxic byproducts of metabolism accumulate in the body. Hemodialysis treatment removes many of the toxins, but noncompliance with the treatment regimen can result in both short- and long- term health consequences. The immediate consequences of excessive fluid intake include increased interdialytic weight gain (IWG), exacerbated hypertension, shortness of breath, and sever muscle cramping. Chronic fluid overload can result in severe health consequences, including congestive heart failure and death" (Everett et al. 1995). Only 25% of patients with this condition follow their treatment. If the risks are so high, why is this so? Everett et al. (1995), believe that the reason for this is stressful life events. The definition of stress in this article is the stimulus model is the frequency of major life events. Minor events are also considered important to the development of illness. The researchers suggest that one reason that the hemodialysis patients are so susceptible to stressful events is that their immune system and coping skills are constantly taxed , due to chronic illness. This study examines the impact of major life events and daily stressful events. Subjects were given the Daily Stress Inventory 58 questions of minor stressors within 24 hours, in which they were to assess the intensity and occurrence of each item listed. They were also given the Social Readjustment Rating Scale 43 items, major life events within 6-24 months. The Interdialytic Weight Gain was also "measured by obtaining the weight of the patient before dialysis treatment and subtracting his or her postdialysis weight from the previous session" (Everett et al. 1995). It was found that major life events had a direct effect on daily stress, and daily stress had a direct effect on interdialytic weight gain.

Conclusion

Three of the four articles in this summary have to do with the influence of stress in specific illnesses. This merely was done out of convenience; results showing stress's effect on illness would probably be the same in individuals without a disease. It is just easier to examine this effect when symptoms are present and can be measured. In the one study which was not based on an illness, basically, the same conclusions were reached. Throughout these articles there are some common themes: there is some connection between stress and illness. Major life events are important in the course of a disease, but minor stressors, which occur on a daily basis, may be more agitating, and have a more profound effect on symptoms of disease. The stress effect was found to be strong. So great, that in the interdialysis weight gain experiment, it even jeopardizes the lives of patients non-compliant to their treatment.

References

Adams, Dammers, Saia, Brantley, Gaydos (1994). Stress, Depression, and Anxiety Predict Average Symptom Severity and Daily Symptom Fluctuation in Systemic Lupus Erythematosus. Journal of Behavioral Medicine, 17, 459-476.

Duffy, Zielezny, Marshall, Byers, Weiser, Philips, Calkins, Ogra, Graham (1991). Relevance of Major stress Events as an Indicator of Disease Activity Prevalence in Inflammatory Bowel Disease. Journal of Behavioral Medicine ,17, , 101- 110.

Everett, Brantley, Sletten, Jones, McKnight (1991). The Relation of Stress and Depression to Interdialytic Weight Gain in Hemodialysis Patients. Journal of Behavioral Medicine, 21, 25-30.

Hills, Norvell (1991). An Examination of Hardiness and Neuroticism as Potential Moderators of Stress Outcomes. Journal of Behavioral Medicine,17, 31-39.

Contributed by Dan Kubacki, December 2, 1997.

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