The
stress response is important for survival and adaptation. The stress response,
which involves both emotional and physiological changes, is an adaptive response
that motivates our behavior so we can protect ourselves. It is turned on by the
brain working in specific neural circuits modulated by neurotransmitters and hormones.
There are important individual differences in humans. Some people may have the
ability to quickly shut down their emotional, behavioral, and hormonal responses
to stressful situations, while others may have prolonged responses. Over time,
these prolonged responses could affect physiology and brain function.
For
example, increased release of cortisol over a long time could affect glucose regulation,
bone density, immune function, and the function of specific brain cells. These
individuals could become vulnerable to developing physical and mental diseases.
Evidence suggests that overactivity of corticotropin-releasing factor, a brain
neurochemical, may play a role in why some people become excessively anxious and
depressed. About 50 percent of depressed patients have overactivity of the stress
hormone response, which is regulated by corticotropin-releasing factor. Whether
this overactivity causes or contributes to depression is unclear. It is also possible
that overactivity of this system may play a role in altering the structure and
function of certain brain cells.
Studies
of childhood experiences may reveal a connection between stress hormone levels
and depression. A study by Spitz examined the psychological condition of orphans
who were hospitalized and provided with a clean and healthy environment but with
very little contact or comfort by the nurses. These children were described as
withdrawn, and social interactions with them became increasingly difficult. In
more recent studies, data suggests that children who have been deprived of contact
or comfort develop alterations in their stress hormonal responses.
Studies
of monkeys also can provide some insight into the relationship between stress
hormones and depression. One long-ago experiment by Harlow focused on monkeys
who were raised apart from their mothers with little or no physical contact with
other animals. When these monkeys became mothers, they were either indifferent
and withdrawn or violent and abusive to their offspring; they were unable to regulate
their own emotions. This suggests that their early experience promoted the development
of a vulnerability that proved to be very important when they became adults.
The
offspring of these motherless mothers, moreover, began to exhibit similar abnormal
behavior. The fact that some of the motherless monkeys were withdrawn and
others were abusive reflects the differences among individuals who experience
trauma. We cant give a complete answer as to why one individual responds
in one way and another responds in a completely different manner. Were dealing
with very complicated brain systems involving numerous brain chemicals interacting
across many brain regions. Scientists hope, that by studying how the stress response
system relates to development and depression, they may be able to develop early
recognition and new treatment strategies, perhaps targeting early environmental
factors as well as the hormonal systems that may be affected.
Adapted
from National Institute of Mental Health.
Personal
Reflection Journaling Activity #7
The preceding section contained
information about Stress Hormone Levels and Depression. Write three case study
examples regarding how you might use the content of this section of the Manual
in your practice.
Online Continuing Education QUESTION
27:
What happened when monkeys who were raised apart from their mothers
with little or no physical contact with other animals, became mothers? To select
and enter your answer go to .
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