STRESS AND HEALTH: Psychological, Behavioral, and Biological Determinants
A substantial amount of research has been done to prove the correlation between stress and physical illness. This research proves that stress. In 50 years of research concerning the links between stress and health, several major Statistics from the Canadian Mental Health Association are alarming in . In a group, discuss the kinds of social and workplace policies that need to be in. Stress and Illness – Key point If you repeatedly turn on the stress-response, or if you cannot appropriately turn off the stress-response at the end of a stressful.
Stress is a normal part of life. You can experience stress from your environment, your body, and your thoughts. Even positive life changes such as a promotion, a mortgage, or the birth of a child produce stress. How does stress affect health? The human body is designed to experience stress and react to it. Stress can be positive, keeping us alert, motivated, and ready to avoid danger. Stress becomes negative when a person faces continuous challenges without relief or relaxation between stressors.
As a result, the person becomes overworked, and stress-related tension builds.
The body's autonomic nervous system has a built-in stress response that causes physiological changes to allow the body to combat stressful situations. This stress response, also known as the "fight or flight response", is activated in case of an emergency.
However, this response can become chronically activated during prolonged periods of stress. Prolonged activation of the stress response causes wear and tear on the body — both physical and emotional. Stress that continues without relief can lead to a condition called distress — a negative stress reaction.
Distress can disturb the body's internal balance or equilibrium, leading to physical symptoms such as headachesan upset stomachelevated blood pressurechest painsexual dysfunctionand problems sleeping. Abstract Stressors have a major influence upon mood, our sense of well-being, behavior, and health. Acute stress responses in young, healthy individuals may be adaptive and typically do not impose a health burden. However, if the threat is unremitting, particularly in older or unhealthy individuals, the long-term effects of stressors can damage health.
Psychosocial interventions have proven useful for treating stress-related disorders and may influence the course of chronic diseases. Our central nervous system CNS tends to produce integrated coping responses rather than single, isolated response changes Hilton Thus, when immediate fight-or-flight appears feasible, mammals tend to show increased autonomic and hormonal activities that maximize the possibilities for muscular exertion CannonHess In contrast, during aversive situations in which an active coping response is not available, mammals may engage in a vigilance response that involves sympathetic nervous system SNS arousal accompanied by an active inhibition of movement and shunting of blood away from the periphery Adams et al.
Although various situations tend to elicit different patterns of stress responses, there are also individual differences in stress responses to the same situation.
The Relationship Between Health and Stress
Across a variety of situations, some individuals tend to show stress responses associated with active coping, whereas others tend to show stress responses more associated with aversive vigilance Kasprowicz et al. Although genetic inheritance undoubtedly plays a role in determining individual differences in response stereotypy, neonatal experiences in rats have been shown to produce long-term effects in cognitive-emotional responses Levine For example, Meaney et al.
The increased serotonin activity leads to increased expression of a central glucocorticoid receptor gene. Interestingly, female rats who receive a high level of nurturing in turn become highly nurturing mothers whose offspring also have high levels of glucocorticoid receptors.
This example of behaviorally induced gene expression shows how highly nurtured rats develop into low-anxiety adults, who in turn become nurturing mothers with reduced stress responses. In contrast to highly nurtured rats, pups separated from their mothers for several hours per day during early life have a highly active hypothalamic-pituitary adrenocortical axis and elevated SNS arousal Ladd et al.
These deprived rats tend to show larger and more frequent stress responses to the environment than do less deprived animals. Because evolution has provided mammals with reasonably effective homeostatic mechanisms e. However, if the threat is persistent, particularly in older or unhealthy individuals, the long-term effects of the response to stress may damage health Schneiderman Adverse effects of chronic stressors are particularly common in humans, possibly because their high capacity for symbolic thought may elicit persistent stress responses to a broad range of adverse living and working conditions.
The relationship between psychosocial stressors and chronic disease is complex. In this review, we focus on some of the psychological, behavioral, and biological effects of specific stressors, the mediating psychophysiological pathways, and the variables known to mediate these relationships.
STRESS AND HEALTH: Psychological, Behavioral, and Biological Determinants
We conclude with a consideration of treatment implications. Childhood abuse is also associated with negative views toward learning and poor school performance Lowenthal Children of divorced parents have more reported antisocial behavior, anxiety, and depression than their peers Short Adult offspring of divorced parents report more current life stress, family conflict, and lack of friend support compared with those whose parents did not divorce Short Studies have also addressed the psychological consequences of exposure to war and terrorism during childhood Shaw A majority of children exposed to war experience significant psychological morbidity, including both post-traumatic stress disorder PTSD and depressive symptoms.
For example, Nader et al. Some effects are long lasting: Exposure to intense and chronic stressors during the developmental years has long-lasting neurobiological effects and puts one at increased risk for anxiety and mood disorders, aggressive dyscontrol problems, hypo-immune dysfunction, medical morbidity, structural changes in the CNS, and early death Shaw Furthermore, there is evidence that stressful life events are causal for the onset of depression see HammenKendler et al.
A study of 13, patients in Denmark, with first psychiatric admissions diagnosed with depression, found more recent divorces, unemployment, and suicides by relatives compared with age- and gender-matched controls Kessing et al. The diagnosis of a major medical illness often has been considered a severe life stressor and often is accompanied by high rates of depression Cassem In fact, in prospective studies, patients with anxiety are most likely to develop major depression after stressful life events occur Brown et al.
Both these disorders have as prominent features a traumatic event involving actual or threatened death or serious injury and symptom clusters including re-experiencing of the traumatic event e. The time frame for ASD is shorter lasting two days to four weekswith diagnosis limited to within one month of the incident.
Surveys of the general population indicate that PTSD affects 1 in 12 adults at some time in their life Kessler et al. Trauma and disasters are related not only to PTSD, but also to concurrent depression, other anxiety disorders, cognitive impairment, and substance abuse David et al. Other consequences of stress that could provide linkages to health have been identified, such as increases in smoking, substance use, accidents, sleep problems, and eating disorders.
Populations that live in more stressful environments communities with higher divorce rates, business failures, natural disasters, etc. A longitudinal study following seamen in a naval training center found that more cigarette smoking occurred on high-stress days Conway et al. Life events stress and chronically stressful conditions have also been linked to higher consumption of alcohol Linsky et al.
In addition, the possibility that alcohol may be used as self-medication for stress-related disorders such as anxiety has been proposed. For example, a prospective community study of adolescents and young adults Zimmerman et al.
Another variable related to stress that could provide a link to health is the increased sleep problems that have been reported after sychological trauma Harvey et al. New onset of sleep problems mediated the relationship between post-traumatic stress symptoms and decreased natural killer NK cell cytotoxicity in Hurricane Andrew victims Ironson et al. Variations in Stress Responses Certain characteristics of a situation are associated with greater stress responses.
These include the intensity or severity of the stressor and controllability of the stressor, as well as features that determine the nature of the cognitive responses or appraisals. Life event dimensions of loss, humiliation, and danger are related to the development of major depression and generalized anxiety Kendler et al. Factors associated with the development of symptoms of PTSD and mental health disorders include injury, damage to property, loss of resources, bereavement, and perceived life threat Freedy et al.The Link Between Stress and High Cholesterol
Recovery from a stressor can also be affected by secondary traumatization Pfefferbaum et al. Other studies have found that multiple facets of stress that may work synergistically are more potent than a single facet; for example, in the area of work stress, time pressure in combination with threat Stanton et al. Stress-related outcomes also vary according to personal and environmental factors. Personal risk factors for the development of depression, anxiety, or PTSD after a serious life event, disaster, or trauma include prior psychiatric history, neuroticism, female gender, and other sociodemographic variables GreenMcNallyPatton et al.
There is also some evidence that the relationship between personality and environmental adversity may be bidirectional Kendler et al. Attaching meaning to the event is another protective factor against the development of PTSD, even when horrific torture has occurred.
Finally, human beings are resilient and in general are able to cope with adverse situations. A recent illustration is provided by a study of a nationally representative sample of Israelis after 19 months of ongoing exposure to the Palestinian intifada. Despite considerable distress, most Israelis reported adapting to the situation without substantial mental health symptoms or impairment Bleich et al.
These changes constitute the stress response and are generally adaptive, at least in the short term Selye Two features in particular make the stress response adaptive. Second, a new pattern of energy distribution emerges.
Energy is diverted to the tissues that become more active during stress, primarily the skeletal muscles and the brain. Less critical activities are suspended, such as digestion and the production of growth and gonadal hormones.
Simply put, during times of acute crisis, eating, growth, and sexual activity may be a detriment to physical integrity and even survival. Stress hormones are produced by the SNS and hypothalamic-pituitary adrenocortical axis. The SNS stimulates the adrenal medulla to produce catecholamines e. In parallel, the paraventricular nucleus of the hypothalamus produces corticotropin releasing factor, which in turn stimulates the pituitary to produce adrenocorticotropin.
Adrenocorticotropin then stimulates the adrenal cortex to secrete cortisol. Together, catecholamines and cortisol increase available sources of energy by promoting lipolysis and the conversion of glycogen into glucose i. Lipolysis is the process of breaking down fats into usable sources of energy i. Energy is then distributed to the organs that need it most by increasing blood pressure levels and contracting certain blood vessels while dilating others.
Blood pressure is increased with one of two hemodynamic mechanisms Llabre et al. The myocardial mechanism increases blood pressure through enhanced cardiac output; that is, increases in heart rate and stroke volume i. The vascular mechanism constricts the vasculature, thereby increasing blood pressure much like constricting a hose increases water pressure.
Specific stressors tend to elicit either myocardial or vascular responses, providing evidence of situational stereotypy Saab et al. Laboratory stressors that call for active coping strategies, such as giving a speech or performing mental arithmetic, require the participant to do something and are associated with myocardial responses.
From an evolutionary perspective, cardiac responses are believed to facilitate active coping by shunting blood to skeletal muscles, consistent with the fight-or-flight response. In situations where decisive action would not be appropriate, but instead skeletal muscle inhibition and vigilance are called for, a vascular hemodynamic response is adaptive.
The vascular response shunts blood away from the periphery to the internal organs, thereby minimizing potential bleeding in the case of physical assault.
Finally, in addition to the increased availability and redistribution of energy, the acute stress response includes activation of the immune system. Cells of the innate immune system e. From there, the immune cells migrate into tissues that are most likely to suffer damage during physical confrontation e. Chronic Stress Responses The acute stress response can become maladaptive if it is repeatedly or continuously activated Selye For example, chronic SNS stimulation of the cardiovascular system due to stress leads to sustained increases in blood pressure and vascular hypertrophy Henry et al.
That is, the muscles that constrict the vasculature thicken, producing elevated resting blood pressure and response stereotypy, or a tendency to respond to all types of stressors with a vascular response. Chronically elevated blood pressure forces the heart to work harder, which leads to hypertrophy of the left ventricle Brownley et al.
The Relationship Between Stress and Physical Illness | Applied Social Psychology (ASP)
Over time, the chronically elevated and rapidly shifting levels of blood pressure can lead to damaged arteries and plaque formation. The elevated basal levels of stress hormones associated with chronic stress also suppress immunity by directly affecting cytokine profiles. Cytokines are communicatory molecules produced primarily by immune cells see Roitt et al.
There are three classes of cytokines. Proinflammatory cytokines mediate acute inflammatory reactions. Th1 cytokines mediate cellular immunity by stimulating natural killer cells and cytotoxic T cells, immune cells that target intracellular pathogens e.
A Th2 shift has the effect of suppressing cellular immunity in favor of humoral immunity. In response to more chronic stressors e. Intermediate and chronic stressors are associated with slower wound healing and recovery from surgery, poorer antibody responses to vaccination, and antiviral deficits that are believed to contribute to increased vulnerability to viral infections e. Chronic stress is particularly problematic for elderly people in light of immunosenescence, the gradual loss of immune function associated with aging.
Older adults are less able to produce antibody responses to vaccinations or combat viral infections Ferguson et al. Although research has yet to link poor vaccination responses to early mortality, influenza and other infectious illnesses are a major cause of mortality in the elderly, even among those who have received vaccinations e. The underlying mediators, however, are unclear in most cases, although possible mechanisms have been explored in some experimental studies.
An occupational gradient in coronary heart disease CHD risk has been documented in which men with relatively low socioeconomic status have the poorest health outcomes Marmot Much of the risk gradient in CHD can be eliminated, however, by taking into account lack of perceived job control, which is a potent stressor Marmot et al.
Other factors include risky behaviors such as smoking, alcohol use, and sedentary lifestyle Lantz et al. Among men Schnall et al. However, in women with existing CHD, marital stress is a better predictor of poor prognosis than is work stress Orth-Gomer et al.
Although the observational studies cited thus far reveal provocative associations between psychosocial stressors and disease, they are limited in what they can tell us about the exact contribution of these stressors or about how stress mediates disease processes.
Animal models provide an important tool for helping to understand the specific influences of stressors on disease processes.
This is especially true of atherosclerotic CHD, which takes multiple decades to develop in humans and is influenced by a great many constitutional, demographic, and environmental factors. It would also be unethical to induce disease in humans by experimental means.
Perhaps the best-known animal model relating stress to atherosclerosis was developed by Kaplan et al. Their study was carried out on male cynomolgus monkeys, who normally live in social groups. The investigators stressed half the animals by reorganizing five-member social groups at one- to three-month intervals on a schedule that ensured that each monkey would be housed with several new animals during each reorganization.
The other half of the animals lived in stable social groups. All animals were maintained on a moderately atherogenic diet for 22 months.
Animals were also assessed for their social status i. The major findings were that a socially dominant animals living in unstable groups had significantly more atherosclerosis than did less dominant animals living in unstable groups; and b socially dominant male animals living in unstable groups had significantly more atherosclerosis than did socially dominant animals living in stable groups.
Other important findings based upon this model have been that heart-rate reactivity to the threat of capture predicts severity of atherosclerosis Manuck et al.
In contrast to the findings in males, subordinate premenstrual females develop greater atherosclerosis than do dominant females Kaplan et al. Whereas the studies in cynomolgus monkeys indicate that emotionally stressful behavior can accelerate the progression of atherosclerosis, McCabe et al. This rabbit model has a genetic defect in lipoprotein clearance such that it exhibits hypercholesterolemia and severe atherosclerosis.
The rabbits were assigned to one of three social or behavioral groups: The stable group exhibited more affiliative behavior and less agonistic behavior than the unstable group and significantly less atherosclerosis than each of the other two groups.
The study emphasizes the importance of behavioral factors in atherogenesis, even in a model of disease with extremely strong genetic determinants. Upper Respiratory Diseases The hypothesis that stress predicts susceptibility to the common cold received support from observational studies Graham et al. One problem with such studies is that they do not control for exposure. Stressed people, for instance, might seek more outside contact and thus be exposed to more viruses.
Therefore, in a more controlled study, people were exposed to a rhinovirus and then quarantined to control for exposure to other viruses Cohen et al. Those individuals with the most stressful life events and highest levels of perceived stress and negative affect had the greatest probability of developing cold symptoms. In a subsequent study of volunteers inoculated with a cold virus, it was found that people enduring chronic, stressful life events i.
Human Immunodeficiency Virus The impact of life stressors has also been studied within the context of human immunodeficiency virus HIV spectrum disease. Inflammation, the Immune System, and Physical Health Despite the stress-mediated immunosuppressive effects reviewed above, stress has also been associated with exacerbations of autoimmune disease Harbuz et al.