chapter 14

Psychoneuroimmunology

refers to the interactions among behavioral, neuroendocrine, and immunological processes of adaptation

Cancer has been hard to study for a number of reasons.

the causes, symptoms, and treatment for each cancer vary. Many cancers have long or irregular growth cycles.

that optimism and active coping strategies protect against stress.

the optimistic law students and students who used fewer avoidant coping methods showed less distress across the quarter. Pessimism, avoidance coping, and mood disturbance were tied to lower natural killer cell cytotoxicity and fewer T cells, suggesting that optimism and coping can be important influences on stress-related distress and immune changes.

Assessing Immune Functioning

1. Assessing the functioning of immune cells 2. Assessing the production of antibodies to latent viruses 3. Assessing levels of immune system products, such as proinflammatory cytokines 4. Using indirect measures, such as wound healing

Self-help groups in which patients share emotional concerns are available and helpful to many cancer patients especially those who have few other personal or social resources

A possible reason for the success of support groups is that the self- help format presents patients with an array of potential coping techniques from which they can draw the ones that fit in with their particular styles and problems

Researchers also assess a person's ability to produce antibodies to a latent virus.

All of us carry around viruses that are inactive. If our bodies begin to produce antibodies this is a sign that the immune system is not working well enough to control these latent viruses. Consequently, levels of antibodies to these latent viruses constitute a measure of how well the immune system is functioning.

Does stress cause cancer?

Although stress generally has not been linked to the onset of cancer, a particular type of stress—lack or loss of social support—may affect the onset and course of cancer.

Researchers have also examined the role of psychosocial factors in the course of cancer—specifically, whether the cancer progresses rapidly or slowly.

Avoidance, or the inability to confront the disease, has been tied to a more rapid course of the disease. Depression can also exacerbate the impact of other risk factors. Cancer progression may be related to use of denial or repressive coping strategies. Avoidant or passive coping is also a risk factor for psychological distress, depression, poor sleep, and other risk-related factors, which may represent additional influences on the course of cancer

Chronically stressful events are linked to adverse effects on almost all functional measures of the immune system.

Chronic inflammation, which can occur in response to chronically stressful conditions contributes to a broad range of disorders, including heart disease and declines in cognitive performance

Researchers can also measure immune-related products in the blood, such as proinflammatory cytokines.

Cytokine levels are indicative of inflammatory activity and may increase in response to stress.

there is a fairly straightforward relationship between depression and immunity, such that the more depressed a person is, the more cellular immunity is likely to be compromised.

Depressive symptoms can be associated with prolonged inflammatory responses as well, which may link depression to other diseases such as heart disease. Depression has been tied to delayed wound healing as well. The adverse effects of depression on immunity may also be mediated by the sleep disturbance that results from depression

Marital disruption and conflict have also been tied to adverse changes in immunity.

Even short-term marital conflict can have a discernible effect on the immune system.

Relaxation may mute the effects of stress on the immune system.

In a study with elderly adults (a group at risk for illness because of age-related declines in immune functioning), participants were assigned to relaxation training, social contact, or no intervention. participants in the relax- ation condition had significantly higher levels of natural killer (NK) cell activity after the intervention than at baseline and significantly lower antibody titres to herpes simplex virus 1. is pattern suggests some enhancement of cellular immunity associated with the relaxation inter- vention.

Researchers believe that altered functioning of the HPA and sympathetic stress systems adversely affect immune functioning in ways that permit cancer to flourish

In particular, natural killer cells, which are involved in the surveillance and destruction of tumor cells, are believed to play a role in tumor surveillance in the body and affect whether a cancer takes hold after exposure.

Cancer is a set of more than 100 diseases that have several factors in common. All cancers result from a dysfunction in DNA—that part of the cellular programming that controls cell growth and reproduction.

Instead of ensuring the regular, slow production of new cells, this malfunctioning DNA causes excessively rapid cell growth and proliferation. Unlike other cells, cancerous cells provide no benefit to the body. ey merely sap it of resources.

The primary function of the immune system is to distinguish between what is "self " and what is foreign and then to attack and rid the body of foreign invaders.

It does so through natural immunity, a generalized defense against pathogens, and specific immunity, which responds to only one invader.

Social support is important for cancer patients' recovery

It improves psychological adjustment to cancer, it can help patients deal with intrusive thoughts and ruminations about the cancer, and it may improve immunologic responses to cancer as well.

Repressive coping appears to be especially common in children with cancer, so this coping style warrants particular consideration in their case.

Negative expectations regarding one's situation have been related to a more rapid course of illness in young cancer patients

Intensive, stressful caregiving has an adverse effect on the immune system

Other studies have found that the stress of caregiving has adverse effects on wound repair

Lonely people have poorer health and immunocompromise, compared to people who are not lonely

People with insecure attachments to others show lower NK cell cytotoxicity, suggesting potential health risks as well. Chronic interpersonal stress as early as adolescence predicts inflam- matory activity over time; this pathway may underlie the relation of social stress to such disorders as depression and atherosclerosis

Brief stressors of several days' duration, such as pre- paring for examinations, show a different pattern.

Rather than altering the number or percentage of cells in the blood, brief stressors lead to changes in cytokine produc- tion, indicating a shift away from cellular immunity and toward humoral immunity

Most cancers are related to socioeconomic status, with low-SES individuals more at risk.

Some cancers are culturally linked through life- style. Some cancers are ethnically linked. Dietary factors are also implicated in cancer de- velopment

In contrast, specific immunity decreases in response to acute short-term stressors.

Specific immunity is slow to develop, so specific immunity would be of little if any help in combating short-term stressors.

stress engages the sympathetic nervous system and the HPA axis, both of which influence immune functioning.

Sympathetic activation in response to stress has immediate effects of increasing immune activity, especially natural killer cell activity.

stress-related changes in hypothalamic adrenocortical functioning have immunosuppressive effects

That is, activation of the HPA axis leads to the release of glucocorticoids such as cortisol; cortisol reduces the number of white blood cells, affects the functioning of lymphocytes, and reduces the release of cytokines, which can reduce the ability of these substances to signal and communicate with other aspects of the immune system.

Two basic principles are important for under- standing the relation of stress and immunity.

The first is that different kinds of stressors require different kinds of defenses, and so a particular immune response may be favored over another in response to certain stressors. A second important principle is that a maximally efficient immune response to any situation entails costs, and so some aspects of immunity may be adaptively suppressed as others are actively engaged.

Researchers also use wound healing or tape strip- ping as a method to study immune functioning.

Wounds heal faster when the immune system is functioning vigorously. Psychological distress impairs the inflammatory response that initiates wound repair

Many cancers run in families, in part because of genetic factors.

on the whole, cancer is more closely tied to lifestyle than to genetics