Question:
Short resolvable stressful moments, such as running for a bus, or an
interview, produce adrenal hormones predominantly adrenalin.
Long term, unresolvable stress produces a different ratio of hormones,
cortisol being more prominent.
And beyond that there is depression, marked by a fall in adrenalin and
a further rise in cortisol
Long term cortisol production is the thing that can cause other health
problems.
I know there are other hormones involved, but does that principal,
changing hormone ratios for different durations of stressor sound
right?
Answer:
Your essentially on the right track. I personally like to look more closely
at the time phenomena involved with the how stress can influence and perturb
the immune system (it is a highly complex field but it encompasses many of
the major multivariate features involved with "stress" and its effect on the
body).
Exposures to psychosocial stressors invariably activate ACTH from the
pituitary which in turns stimulates the release of corticosteroids (cortisol
primarily in humans). These corticosteroids are typically
immunosuppressive. Generally, short durations of stress cause leukopenia
(decrease in circulating white blood cells ~ due to the release by the
stressor of a compound called interleukin 1 (a "transmitter" that allows
interaction between leukocytes, i.e. white blood cells), whereas, more long
term intermittent stress cause involution of the thymus gland (an important
organ involved in the production of a certain kind of lymphocyte;
t-lymphocytes). In fact any sudden change in a schedule of reinforcement
(e.g., frustration at a candy machine b/c no reward is delivered following
insertion of money) can evoke a transient leukopenia. Thus, prolonged and
elevated levels of corticosteroids that accompany chronic episodes of
stress-induced immunosuppression can increase the probability of developing
curtains cancers or other nonpathological conditions (eruptions of herpes
virus blisters on the mouth, i.e. cold sores, or penis/vagina during periods
of stress).
To give you even more of a perspective. It has been shown that academic
stress (exams) are associated with a decrease in the secretion rate of
immunogloblin A (IgA; is involved in humoral or blood-mediated immunity).
Even personality characteristics can play an important for in
differentiators to responsiveness to these types of stress and their
accompanied physiological correlates. Therefore, the individuals own unique
coping strategy will become important in determine the extent and severity
of immunosuppression following chronic elevation in plasma circulating
glucocorticoids during stress.
So the major point that I am trying to bring up is that the nature of the
stress pattern and cognitive styles for coping will affect
immunoresponsiveness following exposure to stress. Often the timing of the
immunosuppression that accompanies stress will be critical with respect to
the occurrence of a tumor or development of cancer. Previous studies have
shown that dexamethosone (a synthetic corticosteroid) administered 7 days
before tumor implantation, enhances immunocompetence (tumor is rejected or
shrunk). Moreover, injection of dexamethosone 7 days after tumor
implantation results in immunosuppression or impairment. Immunosuppression
or immunofaciliation can occur as undershoot/overshoot adjustments to sudden
stresses. The state of the organism, which is influenced by stressors, at
the time of the viral infection will determine the outcome of immune
disorders.
One shouldn't look at stress as completely deleterious. As you stated
earlier, typically it is chronic levels of stress that produce negative and
problematic aspects on health. Much of the literature and research has
suggested that even the type of stressor may be important. We often employ
nebulous terms like "stress" that really don't mean very much. Certain
types of stress, depending on the context, can either produce positive or
negative effects.
And you gave an example of administering dexamethosone 7 days before and
after implantion of a tumor. Would you please be so kind to post the
reference of this publication. I'm an undergraduate in psychology in The
Netherlands and I am to write a research proposition in the field of
psychoneuroimmunology.
There are many cited examples pertaining to the ideas and concepts that I
brought up in a earlier post. I would suggest looking at any of the by
Sklar and Hymie Anisman (from Carleton University) work. (do a pubmed
search and you find the exact references).
To give a bit of context Sklar and Hymie were the first to essentially
develop (and investigate) the effect of stress pattern and
immunoresponsiveness. (basically they developed or pioneered the "learned
helplessness" paradigm).
