Health Psychology Research Paper

The formal emergence of health psychology in the 1970s was influenced by a variety of factors. By that time, for industrialized nations infectious illnesses such as smallpox and influenza were no longer the leading cause of death. Through advances in basic biomedical science and its application in public health, vaccines, antibiotics, and acute clinical care, infectious illnesses had been replaced by several chronic diseases as the leading sources of morbidity and mortality. Cancer, coronary heart disease, cerebrovascular disease, and diabetes differ from infectious diseases in three fundamental ways that assured the emergence of health psychology. First, these illnesses are influenced by behavior. Daily habits or ‘lifestyle’ factors are major contributors to their development and course. Second, unlike the acute crisis of infectious illness, chronic illnesses have far-reaching impacts on emotional, social, and vocational adaptation over long periods of time. Finally, behavior change is a key component of care for such conditions. Hence, behavior plays a prominent role in the development, impact, and management of the current major health threats in industrialized nations, making psychological research and practice essential in comprehensive medical research and care. This is the case for our most common chronic diseases, such as cancer and heart disease, and for more recently emerging diseases such as HIV/AIDS.

1. History, Foundations, And Related Disciplines

The emergence of health psychology was made possible by a variety of developments at the interface of behavioral and biomedical science. The work of Walter Cannon, Hans Selye, and other physiologists working in the 1930s, 1940s, and 1950s described physiological changes induced by environmental stressors and negative emotions (e.g., the ‘fight or flight’ response). This identified a pathway through which psychological factors could impact physical health. Shortly thereafter, epidemiologists determined that several behaviors—notably smoking, excessive intake of fat and calories, and low levels of physical activity—were risk factors for the subsequent development of cancer and cardiovascular disease. Elsewhere, psychologists were beginning to explore the application of learning principles to the treatment of physical conditions, as in the seminal work by Neal Miller on the operant conditioning of physiological responses and the work of William Fordyce on the use of behavioral contingencies in the management of pain and disability. At the same time, clinical psychologists—led primarily in the United States by Joseph Matarazzo—were beginning to establish research and clinical roles within academic medicine through appointments to medical school faculties and the establishment of related academic medical departments and services.

In response to a variety of government and organizational initiatives, health psychology became a recognized subdiscipline in the late 1970s. For example, it was established as a formal division within the American Psychological Association in 1978, and the first health psychology handbook was published in 1979 (Stone et al. 1979). At the same time, an interdisciplinary field—behavioral medicine—was established, sharing the focus on behavior in the development, prevention, and management of medical conditions (Schwartz and Weiss 1978). Although most health psychologists view themselves as engaging in behavioral medicine, that field includes concepts, methods, and professionals from medicine, public health, and other disciplines. Hence, health psychology is a component of this broader field. Because health psychology addresses the impact of behavior on health beyond its role in established disease and disability, its emergence represented a departure from older fields such as medical and rehabilitation psychology. The former refers traditional clinical psychological services (e.g., assessment, consultation, and psychotherapy) within medical settings, whereas the latter refers to similar services and research in the context of physical disabilities (e.g., spinal cord or brain injuries).

The biopsychosocial model is a conceptual cornerstone in health psychology and behavioral medicine. In the traditional biomedical model which underlies much of modern medical research and practice, disease is seen as stemming from disordered biological systems. Aberrations in biochemistry or physiology cause disease, alter its course, and are intervention targets. Psychological or social factors are seen as largely irrelevant. In a landmark paper, Engel (1977) articulated the biopsychosocial model as an alternative. Here biological, psychological, and social processes are seen as inter-related influences on and effects of health and illness. The onset, course, and treatment of illness is best understood as involving each of these interacting, reciprocally determined levels of analysis.

Current research in health psychology consists of three general topics. The first—health behavior and prevention—focuses on the determinants of behaviors that influence disease (e.g., diet, exercise, smoking), and the effectiveness of interventions to reduce these risks. The second—stress and illness—focuses on direct connections between psychological processes and the development of illness. Rather than the intervening effects of habits and lifestyle factors, this research examines the impact of environmental stress and related personality and social processes on psychobiological mechanisms and the pathophysiology of disease. The third research area—the psychosocial impact and management of illness—focuses on the emotional and social consequences of illness and psychological interventions intended to improve adjustment and supplement traditional medical care.

2. Health Behavior And Prevention

Decades of epidemiological research have demonstrated the impact of daily habits on health. A variety of conceptual models have been developed to describe the determinants of these behaviors, and thereby provide targets for interventions intended to reduce health risks (Armitage and Conner 1999). For example, the health belief model suggests that several cognitive factors influence health behavior: the value or importance an individual places on health; beliefs about vulnerability conferred by a specific behavior; beliefs about the severity of the related illness; the individual’s beliefs about the effectiveness of a behavior change in reducing risk; and a view of the relative costs and benefits of that change. From this perspective, interventions designed to increase the perceived importance of good health, strengthen the belief that a specific behavior impacts health, make clear the severity of the disease or condition to be prevented, emphasize the risk reducing impact of behavior change, and make salient the relative benefits of this change in promoting more healthy lifestyles. Based on this and closely related models of health behavior, interventions ranging from individual counseling to national advertising campaigns have been developed.

Other models of health behavior describe the adoption of a healthier lifestyle as a cyclical process, in which people consider and initiate behavior change, often revert to less healthy habits, and perhaps later renew their efforts (Weinstein et al. 1998). Different interventions may be optimal at different stages in this process. Informational strategies derived from the health beliefs model may be best for individuals who are in the earliest stages, either before or as they begin to consider a change in lifestyle. In contrast, active planning about the nature of ‘high risk’ situations where a return to old habits is likely and rehearsal of strategies for avoiding or managing such relapses may be useful after they have initiated changes. A specific health behavior change can also be addressed to many different intervention levels. For example, to increase regular physical activity, individual level counseling can be supplemented by small group or organizational level interventions such as couple, family, or workplace programs. Further, public policy level interventions can be effective, such as taxes to increase the cost of cigarettes or the construction of public recreational facilities.

For many health behavior changes, the biological level of analysis is a critical consideration. Nowhere is this more evident than in the case of smoking cessation. It has become quite clear that nicotine is an addictive component of tobacco, and that habitual smoking can be seen, in part, as the self-regulation of this addictive agent. Hence, nicotine replacement therapy (e.g., nicotine gum or trans-dermal patches) is a valuable addition to psychological or behavioral approaches.

The biopsychosocial approach to health behavior change is also evident in our current understanding of the nature and treatment of obesity. Body weights 25 percent or more above normal are associated with increasing risk of diabetes, high blood pressure, coronary heart disease, and stroke. Further, in industrialized countries, the prevalence of obesity is increasing. Vulnerability to obesity is influenced by genetic factors. There are several likely physiological ‘sites’ of these genetic vulnerabilities, including resting metabolic rate, the degree of weight gain in response to overfeeding, and the location of fat deposition in response to excess energy intake. The energy balance model identifies two additional influences on obesity—the amount of energy (i.e., calories) consumed and the amount expended. Simply, individuals gain weight when the amount of energy consumed exceeds energy expended. Hence, caloric restriction (i.e., dieting) and increased energy expenditure through physical activity are critical determinants of obesity and essential components of treatment. However, larger sociocultural and economic factors also affect obesity. In industrialized nations, the availability of high-fat, energy-rich foods has increased dramatically in recent decades, and levels of leisure time and work-related physical activity have decreased. Especially for the genetically vulnerable, this sociocultural and economic context for the individual’s energy balance can be a ‘toxic environment’ promoting obesity (Hill and Peters 1998). Hence, our understanding of health behavior influences on obesity is facilitated by the comprehensive perspective of the biopsychosocial model.

Smoking and obesity are very difficult to treat in adulthood, even with multicomponent, multilevel interventions. Research and practice on health behavior and prevention has begun to address the prevention of unhealthy behavior. That is, rather than focus on improved methods of smoking cessation and weight loss in adults, more attention has been paid recently to methods of preventing smoking and obesity in childhood and adolescence, and on the modification of these and other risk factors in youth. This trend has necessitated a developmental view of health habits and behavioral risk factors, as well as age-appropriate interventions at the individual, family, school, and community levels. Even though the modification of health behaviors in adulthood remains a priority in health psychology, early prevention is likely to become more widespread in the future.

The emergence of health psychology and its focus on health behavior change preceded by only a few years the identification of Acquired Immune Deficiency Syndrome (AIDS) and the HIV infectious agent. Quickly, epidemiological and clinical research identified intravenous drug use and unprotected sexual activity as primary risk factors. As a result, health psychologists have been closely involved in efforts to prevent HIV infection. As in other health behavior change efforts, multiple levels of intervention have been employed. Individual level programs include educational interventions based on the health behavior model and related approaches such as enhancing the individual’s skill in negotiating condom use during intercourse. Community level approaches have focused on changing norms regarding sexual behavior and advocacy of ‘safer sex’ by visible members of high-risk communities. Institutional approaches have involved increased access to clean needles for drug users.

3. Stress And Disease

A second major focus of research and practice in health psychology involves the impact of stress, negative emotions, and other psychosocial factors on the development of physical illnesses. In contrast to the effects of health behavior described above, this area addresses more direct connections between mind and body. In the general view guiding this research area, the stresses and strains of everyday life exact a toll on the individual’s physiology. Accumulated over many days, months, or even years, such physiological changes can initiate, hasten, or exacerbate the development of illness. Further, some characteristics of the individual’s personality or social environment can make them more or less susceptible to these psychobiological influences on disease.

A growing array of environmental and personality characteristics have been identified in epidemiological research as risk factors for physical illness and premature death. For example, individuals who are socially isolated or report low levels of available social support are at increased risk of cardiovascular disease, cancer, and premature death (House et al. 1988). High levels of job stress also place people at greater risk of illness (Schnall et al. 1994), as does the chronic stress of caring for seriously ill family members (Schulz and Beach 1999). Individuals who are prone to anger and hostility are at increased risk of developing cardiovascular disease and dying prematurely, as are people who report symptoms of anxiety, depression, pessimism, and hopelessness (Smith and Gallo 2001).

People who are socially isolated, experiencing high levels of job stress, or prone to negative emotions may be more likely to smoke, overeat, consume too much alcohol, or avoid regular exercise. These health behaviors could account for some of the effect of the social environment and personality on health. However, the association of these psychosocial risk factors with subsequent morbidity and mortality remains significant even when the effects of health behavior are controlled (Adler and Matthews 1994). The prevailing view in this research area is that the physiological effects of stressful environments and negative emotions are the link between psychosocial risk factors and subsequent disease. These mechanisms are best understood in two general pathways—the effects of stress on the cardiovascular system (Rozanski et al. 1999) and its effects on the immune system (KiecoltGlaser and Glaser 1995).

Environmental threats and demands evoke transient increases in heart rate, blood pressure, and concentrations of various hormones (e.g., epinephrine, norepinephrine, cortisol, etc.). In human and animal research, over time these stress-induced physiological changes appear to promote more enduring levels of high blood pressure, and initiate and hasten the development of atherosclerosis in the coronary and carotid arteries. Atherosclerosis in these sites increases the risk of coronary heart disease and stroke, respectively. Environmental stressors and the brief physiologic changes they evoke can also precipitate acute manifestations of cardiovascular disease (e.g., temporary reductions in oxygen supply to the heart muscle) among individuals with pre-existing atherosclerosis (Rozanski et al. 1999). Further, psychosocial risk factors identified in epidemiological studies as risk factors for cardiovascular disease tend to be related to this psychophysiological mechanism. For example, social support generally reduces the magnitude of these stress-induced physiological reactivities (Uchino et al. 1996), and personality characteristics associated with increased risk of cardiovascular disease such as hostility are associated with more pronounced cardiovascular and neuroendocrine reactivity (Smith and Gallo 2001). Additional evidence of this mechanism comes from nonhuman, primate models of environmental stress, individual differences in social behavior, and the development of atherosclerosis. For example, subjected to the chronic stress of being housed with new cage-mates every few weeks, socially dominant but not subordinate male monkeys develop more severe atherosclerosis than when they are left in stable, less stressful housing conditions. Presumably, the recurring threats to status among dominant animals and the effort required to reassert status evoke physiological reactivity. Further, this effect can be prevented when the input of the sympathetic nervous system to the heart is blocked pharmacologically (Manuck et al. 1995). That is, reduction of the usual cardiovascular ‘fight or flight’ response though pharmacologic blockade prevents the otherwise unhealthy effect of psychosocial factors on atherosclerosis. Such findings provide the outlines of an answer to age-old questions about the influence of the mind on the body, and suggest that stress reduction could be useful in the treatment of cardiovascular disease. Interventions designed to reduce psychological stress have been found to produce beneficial effects on the health of patients with coronary heart disease (Rozanski et al. 1999).

A variety of illnesses from the common cold to some forms of cancer are influenced by the immune system, as is the rate at which wounds heal. The immune system is a complex set of structures and processes, the overall function of which is to identify and destroy foreign bodies (e.g., viruses) and aberrant cells (e.g., malignancies), and to facilitate repair of damaged tissues. Reductions in immune system functioning render the individual more susceptible to conditions it otherwise controls. A growing body of evidence suggests that environmental stress and factors that influence the individual’s susceptibility to stress impact immune functioning (Rabin 1999). Factors as diverse as the stress of final examinations to marital discord have been found to reduce immune functioning. This interdisciplinary field, psychoneuroimmunology (PNI), is the second area in which the study of mind–body connections is quite advanced. Nearly all of the psychosocial variables identified in epidemiological research as risk factors for disease have been found to be related to immune functioning (KiecoltGlaser and Glaser 1995).

Health behaviors might be responsible for some effects of stress on immune functioning. Smoking, inactivity, poor diet, and even sleep deprivation can produce deficits in immune functioning, and are therefore plausible links between stress and immune functioning. However, as in the case of research on cardiovascular disease, statistical control of health behaviors does not eliminate the effect of life stress and chronic negative emotions on immune functioning. As described above, environmental stress and negative emotions are associated with heightened circulating levels of several neuroendocrine factors such as cortisol and catecholamines. These neuroendocrine responses can disrupt immune functioning. It is not clear that the type and degree of immune disruption produced by stress is sufficient to account for the effects of such psychosocial risk factors on the development and course of even minor illnesses, let alone conditions as serious as cancer. Further, although some studies have demonstrated that stress-reducing interventions can have positive effects on immune functioning even among high-risk groups such as individuals with HIV, the evidence of substantial health benefits of interventions based on the PNI literature is preliminary. Nonetheless, the sophistication and clinical implications of this research area are growing rapidly.

4. Psychosocial Aspects Of Medical Illness And Care

The third major topic in health psychology involves the psychosocial impact of acute and chronic medical illness, and the usefulness of psychological interventions as adjuncts to standard medical care. Some research is intended to identify the type and extent of psychosocial impacts of medical illness such as pain, disability, emotional distress, and disruption of personal relationships. Other work seeks to identify modifiable psychosocial influences on these outcomes (e.g., social support, coping styles, etc.), as well as psychosocial influences on the disease process itself (e.g., depression). Such studies can guide the development of psychosocial interventions. Although the patient is typically the focus of such interventions, some are directed at family members, caregivers, or even members of the healthcare team.

An early example of this topic was Irving Janus’s psychological study of surgical patients. Based on patient interviews, Janus described a curvilinear association between the patient’s anxiety before an operation and subsequent physical recovery. Those with moderate levels of presurgical anxiety experienced the least pain and the most rapid recovery compared to patients with very low or high levels. Janus argued that moderate anxiety facilitated the ‘work of worry,’ helping patients to develop realistic expectations and prepare to cope with later discomfort. In contrast, patients with high levels of preoperative anxiety were too distressed to engage in adaptive preparations, and patients with very low levels preoperative distress were not sufficiently motivated to prepare. Decades of subsequent research have indicated that presurgical anxiety is related to postoperative recovery in a simple linear manner (i.e., greater preoperative distress is associated with slower and more complicated recovery), providing the impetus for now routine psychological preparation of patients undergoing many potentially stressful medical procedures (Contrada et al. 1994). The provision of social support and information, hypnosis and relaxation therapies, and rehearsal of distraction and other coping strategies have been found to be effective in reducing emotional and physical discomfort, reducing medical complications, and accelerating wound healing and recovery after invasive diagnostic procedures, chemotherapy, childbirth, and even open heart surgery (Kiecolt-Glaser et al. 1998). In the case of young children, interventions intended to reduce parents’ distress can facilitate the child’s recovery, presumably by enhancing the parent’s ability to comfort the child. These interventions are cost effective; interventions as brief as 30 minutes can reduce the length of hospitalizations by a day or more (Devine 1992). Research in this area suggests it is important to match interventions and the patient’s coping style. Additional information is useful for patients who prefer involvement in their care, whereas training in distraction is best for patients who manage stress with avoidance.

Chronic illnesses such as coronary heart disease, cancer, and diabetes create many burdens for patients. These conditions pose the threat of further limitations and early death, often are associated with discomfort, disrupt social and vocational functioning, and involve unpleasant medical interventions and demands for patient behavior change. These threats to quality of life are in and of themselves important targets for health psychology interventions. However, emotional distress and poor adherence to prescribed medical regimens can contribute directly to poor medical outcomes. Interventions to facilitate coping with chronic disease, managing unpleasant symptoms, and making necessary changes in health behavior can improve functioning among these individuals and in some cases improve prognoses (Compas et al. 1998, Dusseldorp et al. 1999). For some diseases (e.g., essential hypertension, diabetes), behavioral interventions for changes in diet, increased physical activity levels, weight loss, and adherence to medical regimens are particularly effective, as these patient behaviors are key components of medical management. The patient’s success in implementing and maintaining these behavior changes is a central determinant of health. In other conditions (e.g., arthritis, headache, chronic back pain), psychological interventions are useful additions to standard care. Stress management, training in pain coping techniques, reinforcement for increasing levels of physical activity, and interventions designed to improve adaptive communication in couples and families have been found effective for reducing pain and reliance on pain medication, and in increasing functional activity levels (Compas et al. 1998). HIV/AIDS poses nearly all of these challenges in that patients are faced with a life-threatening and sometimes disabling disease, painful and distressing symptoms, and the necessity of adherence to complex medical regimens. Behavioral interventions to reduce stress, control unpleasant symptoms and treatment side effects, and improve adherence are valuable additions to HIV/AIDS care (Sikkema and Kelly 1996).

5. Emerging Challenges And Opportunities In Health Psychology

The rapid growth and evolution of health psychology seems likely to continue. Developments in basic and applied research in each area of the field have included many contributions to our understanding of health and illness, and to efforts to prevent and manage illness. Three factors are likely to shape health psychology in years to come. First, rising costs of medical care will continue to encourage the development of effective methods to prevent illness, maximize the benefits of care and limit its costs, and reduce the economic impact of illness. Although psychological interventions face growing competition from traditional medical services in a tightening climate in healthcare financing, effective interventions of any type will be well received.

Second, all areas of medical science and practice, including health psychology and behavioral medicine, must increase attention to the nature and management of health problems across diverse segments of the population. The growing concern with women’s health and the health of ethnic minorities are obvious examples of this issue. Behavioral influences on health, the impact of illness on psychosocial functioning, and optimal intervention strategies in prevention and management are likely to vary across these groups. More recently, it has become clear that socioeconomic status is also a critical consideration. Within industrialized nations, socioeconomic status is related to health and life expectancy. Health behavior, environmental stress, and access to medical care are important factors in this association (Adler et al. 1993). Hence, research and applied agendas in health psychology are likely to shape and be shaped by the emerging emphasis on the socioeconomic gradient in health. Of course, behavioral issues are no less important in the health of poorer nations, and an emerging ‘world health’ perspective will identify new roles for health psychology.

Finally, advances in basic and applied medical science will continue to shape health psychology. For example, developments in medical imaging have made it possible to study the impact of stress and other psychological factors on disease in more definitive ways. The revolution in medical genetics is making it possible to study gene behavior and gene environment interactive effects on disease more precisely, and may create the opportunity to focus behavioral risk reduction on those at greatest risk. The development of the artificial kidney and organ transplantation procedures created the need to understand the psychosocial aspects of new medical technologies. Similarly, advances in genetic testing to assess risk of illnesses such as cancer have created a new area of psychosocial research. The last three decades of theory, research, and practice in health psychology have produced remarkable growth and innovation. Although the future is difficult to predict, it appears to hold even more progress and impact for this recent variety of social and behavioral science.

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