Stress
and Disease
For thousands of years, people
believed that stress made you sick.
Up until the nineteenth century, the
idea that the passions and emotions
were intimately linked to disease
held sway, and people were told by
their doctors to go to spas or
seaside resorts when they were ill.
Gradually these ideas lost favor as
more concrete causes and cures were
found for illness after illness. But
in the last decade, scientists have
been rediscovering the links between
the brain and the immune system.
The Immune System and the
Brain
When you have an infection or
something else that causes
inflammation such as a burn or
injury, many different kinds of
cells from the immune system stream
to the site. All these types of
immune cells must coordinate their
actions, and the way they do that is
by sending each other signals in the
form of molecules that they make in
factories inside the cell. They can
also go through the bloodstream to
signal the brain or activate nerves
nearby that signal the brain.
These immune molecules can induce
a whole set of behaviors that we
call sickness behavior. You lose the
desire or the ability to move, you
lose your appetite, you lose
interest in sex, to help us conserve
energy when we’re sick so we can
better use our energy to fight
disease.
They also activate the part of
the brain that controls the stress
response, the hypothalamus which
causes blood levels of the hormone
cortisol to rise. Cortisol is the
major steroid hormone produced by
our bodies to help us get through
stressful situations. But it
wasn’t until very recently that
scientists realized the brain also
uses cortisol to suppress the immune
system and tone down inflammation
within the body.
Stress and the Immune System
This complete communications
cycle from the immune system to the
brain and back again allows the
immune system to talk to the brain,
and the brain to then talk back and
shut down the immune response when
it’s no longer needed.
If you’re chronically stressed,
the part of the brain that controls
the stress response is going to be
constantly pumping out a lot of
stress hormones. The immune cells
are being bathed in molecules which
are essentially telling them to stop
fighting. And so in situations of
chronic stress your immune cells are
less able to respond to an invader
like a bacteria or a virus.
People in stressful situations
show a prolonged healing time, a
decreased ability of their immune
systems to respond to vaccination,
and an increased susceptibility to
viral infections like the common
cold.
Controlling the Immune Response
Problems between the brain and
the immune system can go the other
way, too. If for some reason
you’re unable to make enough of
these brain stress hormones, you
won’t be able to turn off the
immune cells once they’re no
longer needed. This results in
autoimmune diseases like allergies
or rheumatoid arthritis.
Taking Control Now
A growing number of studies show
that, to some degree, you can use
your mind to help treat your body.
Support groups, stress relief, and
meditation may, by altering stress
hormone levels, all help the immune
system. For example, women in
support groups for their breast
cancer have longer life spans than
women without such psychological
support.
There are several components of
stress to think about, including its
duration, how strong it is, and how
long it lasts. Every stress has some
effect on the body, and you have to
take into account the total additive
effect on the body of all stressors
when considering how to reduce
stress.
So if you can learn to feel that
you’re in control or actually take
control of certain aspects of the
situation that you’re in, you can
reduce your stress response. And
anything you can do to reduce the
stress of your situation is
healthful.