(and other stress related diseases)
The importance of PsychoNeuroImmunology
An introduction to the immune system
Function is measured in Psychoneuroimmunology research
Research on Stress & Social Support with PNI, Cancer, HIV & CHD
The effect of stress on immune functioning
The effect of mood on immune functioning
Personality and Cancer
Social Support and immune functioning
Proposed biological mechanisms to explain Psychoneuroimmunology
Future directions for Psychoneuroimmunology research
(and other stress related diseases)
Review the psychological state, health relationship, function of the immune system, the methodological issues for researchers, evidence, and possible mechanisms.
The Importance of Psychoneuroimmunology
The relationship between immunocompetence, or one's functional efficacy of immune response, and psychological experiences and outcomes is central to this topic.
Psychoneuroimmunology (PNI) involves interest in the biological mechanisms responsible to specific and general responses of the bio-psycho-social agent. This field examines both possible ways to stave off or moderate stress along with assessments of immune system functioning or state.
As we have already considered, the field of health psychology places a great deal of stake in explanation and prediction of the relationship between mental and physiological states. Psychological tools for 'measuring' psychological states and traits is related to physiological and behavioural measures of immune activity and health promoting behaviours.
Poole et al. (2015)
Consideration of time frame is important in the study of PNI,
where both acute or short-term stressors as well as
chronic or long term effects are considered.
As such short term changes in the immune
are measured in conjunction with short term stressors
(e.g., daily hassles, sudden events).
fluctuations in the immune system function may be measured
over the average day as well as over an period of months.
Where such longer term
stressors are considered
(e.g., trait anxiety, workplace stress, marital problem,
financial challenges, chronic illness or terror).
As pointed out in
Selye's research on stress, longer term
stressors lead to the GAS, including the reactive resistance
of parallel biological systems. Because of the multiplicity of responses,
the singular effects of measurements of any specific response
will be difficult to determine.
Statistical issues arise when considering multiple measures or variables.
Some of these are positive and some are negative. The positive ones are that, generally speaking, more (relevant) variables means better prediction of the outcome or target variable.
Multi-variable Methods typically used here are correlation, multiple regression, factor-analytical, or path analysis.
Factorial designs are also used under experimental treatments. Here the so called main and interaction effects are examined.
downfall of making multiple predictions in a given study is:
that the more statistical relationships examined, the greater
the likelihood that an erroneous relationship will be established.
In other words, each relationship
between variables is examined
and a decision about whether or not it is thought to be real is made
based upon the probability that it will be true,
given known parameters, 95 times out of 100.
significance is this level of 05% chance of error,
sometimes placed more conservatively at 01% chance of error.
While this level may be achieved there may or may not be a
clinically significant difference in outcome or change of symptoms or state.
research offers the possibility of examining physiological
responses to real stressors in natural situations. The challenges
here are that cohort and contamination of data by extraneous variables
may be more likely. These are expected in cross-sectional
studies and longitudinal studies, respectively.
research offers a greater degree of
in making 'cause and effect' attributions about the variables
through controlled experimental studies.
However, the lack of natural situations may
alter the response
of the individual against their exposure to an known antigen.
researchers ability to expose healthy people to
pathogens is an ethical issue that leads to the use of
quasi-experimental or natural experimental studies
(e.g., natural prevalence, disaster response).
An Introduction to the Immune System
are microorganisms that are foreign to the human body
and may cause disease (e.g, viruses, bacterial, fungi, parasites). you tube
Pathogensare referred to as pathogens when they potentially cause death.
or diseases may be localized,
or situated in only one area of the body which may also
be focalized where they send toxins out throughout the body.
They may also be systemic,
affecting the entire body.
Internal systems of attack on these antigens take various forms,
primarily through the development of specific and acquired immunity.
are a mainstay in the immune system,
including B-cells, T-cells and NK-cells (natural kills). utube
system memory maintains small numbers of "B memory cells"
that enable the body to create immunoglobulins and antibodies
when re-exposed to an antigen.
Taking about 5 days to produce a strong response the
produce antibodies that are specific to that antigen (e.g., water parasites).
The action of
B-lymphocytes to produce antibodies is aided through
helper T-cells (CD4) which produce cytokines called interleukins
(e.g., leukin-1, interleukins-2). Suppressor T-cells (CD8)
work as "off switches" for the immune system.
to one's own cells usually occurs where antibodies
are not produced against one's own cells,
except in auto-immune disorders (e.g., arthritis).
immunity operates through the general response
of swelling and phagocytosis.
How Immune-System Function is Measured in PNI Research
is the primary method used for dependent variables in PNI studies.
As such, one's immunocompetence is measured by one or more cell type counts.
assay is performed to count levels of B-cells, T-cells and NK-cells
to determine a minimal number or varied balance among these white blood cells.
Function tests are done to asses immunocompetence in action, across time.
These are done in vitro ( in the test tube) as well as in vivo (in the human body)
for a specified period of time.
In vitro studies will involve the addition of a mitogen (agent to increase activity) to a blood sample (e.g., Con A, PHA, PWM), showing greater or lesser responses under various psychological states or conditions (e.g, confrontation).
A second common approach makes use of the NK cell cytotoxic assay that shows activity of NK cells. Others like the herpesvirus or Epstein-Barr virus counts may also be used to assess immune functioning.
Specific Ab responses may also be made at the infection or injection site.
on Stress, Mood, Social Support & Personality
with PNI, Cancer & HIV
In various studies, the biological has been examined against a host of psychological and social factors that have shown some impact on immune functioning. Some such variable examined include: personality traits, psychological states or moods, acute and chronic stress, social support and coping styles.
The Effect of Stress on Immune Functioning
Immunosuppression is often observed in association with experiences of stress. Lazarus & Folkman (1984) define stress as "an aversive condition in which the demands of a situation are perceived to be greater than our ability to cope with them (Poole at al., p. 65) .
Responses may be observed in as few a five minutes or as long as 5 days. Some dispositional differences in physiological reactivity have been cited by Poole et al with respect to cortisol levels and URIs (upper respiratory infections).
(1997) reports that PTSD Viet Nam vets were more likely to have circulatory, metabolic
digestive or muscular ailments. They were 2.4
times more likely to have these medical problems, effects maintained at 20 year
et al. also cite studies on Three Mile Island residents, hurricane Andrew
survivors, Gulf War vets, earthquake victims and men and women going through
divorce. Here they point out that:
Three-Mile residences had elevated herpes virus
indicating compromised immunity after 10 years.
Gulf war vets had clusters of symptoms associated
apparently maintained partially through classical conditioning.
Divorced or separated women had immune compromise on a variety of
while men who initiated the break-up had better immune function than did those
whose partners initiated the split.
Stress & URI
have shown that colds, flu and bronchitis are more likely among those who have
recently undergone traumatic life events or prolonged
et al. report filed studies that subjective self-report measures are commonly
used to measure stress in conjunction with other characteristics like situation
and dispositional anxiety.
Via et al (1996) reported that people with generalized
anxiety disorder had
higher stress-intrusion scores (in vitro lymphocyte activity) as well as ( 3
times) more URI related sick days taken.
of the challenges of field studies is the lack of control over amount or level
controlled experiments on URIs, antigens are often administered through nasal
sprays in viral
the other hand, the impactof intact
social support systems can be examined through field studies, where it
has been found that larger and more diverse social support systems appear to
lessen the likelihood of cold infections (Cohen et al., 1997).
Other studies cited by Poole et al. have indicated that positive life events can have a negative impact on immune functioning.