Post-Traumatic
Stress Disorder or PTSD occurs by failure to recover after
experiencing or witnessing a terrifying event such as military combat, natural
disasters, terrorist incidents, serious accidents, or physical or sexual
assault in adult or childhood. Most survivors of trauma return to normal given
a little time, but some individuals may develop PTSD.
PTSD patients have
stress reactions that do not go away or may even get worse over time. They often
relive the experience through nightmares and flashbacks, have difficulty
sleeping, and feel detached or estranged.
The symptoms can be severe enough and can last long enough to impair the
person’s daily life significantly. So, what
happens inside of the body to cause PTSD?
Normally, during a traumatic event, the body responds to the threat by going into “flight or fight” mode.
It releases stress hormones, like adrenaline and norepinephrine, to provide a
burst of energy. After the trauma passes, in most people the body returns to
“normal” mode. However, in people suffering from PTSD the brain is stuck in danger mode. So, why do some people develop PTSD while others don’t?
Neuroimaging
studies on the brains of PTSD patients show that several regions differ
structurally and functionally from those of healthy individuals. The amygdala,
the hippocampus, and the ventromedial prefrontal cortex that play a role in
triggering the typical symptoms of PTSD are regions that impact the stress
response mechanism in humans. The PTSD victim, even long after his or her
experiences, continues to perceive a threat and respond to stress.
The most significant neurological impact of trauma is
mediated by the hippocampus. PTSD patients show a considerable reduction in the
volume of the hippocampus.
This region of the brain is responsible for memory functions. It helps an
individual to record new memories and retrieve them later in response to
specific and relevant environmental stimuli. The hippocampus also helps us
distinguish between past and present memories.
PTSD patients with reduced hippocampal volumes lose the
ability to discriminate between past and present experiences or interpret
environmental contexts correctly. Their particular neural mechanisms trigger
extreme stress responses when confronted with environmental situations that
only remotely resemble something from their traumatic past. PTSD treatments
help patients move on.
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on to our next blog – and Behold Biology NSU!
Sources
1.
”Post-Traumatic Stress Disorder” National
Institutes of Health. U.S. Department of Health and Human Services. Web. 17
Apr. 2017. https://medlineplus.gov/posttraumaticstressdisorder.html
2.
"The
Science Behind PTSD Symptoms: How Trauma Changes the Brain" World of
Psychology. N.p., 11 Sept. 2015. Web. 17 Apr. 2017. https://psychcentral.com/blog/archives/2015/09/16/the-science-behind-ptsd-symptoms-how-trauma-changes-the-brain/
3.
"The
Anatomy of Posttraumatic Stress Disorder" Psychology Today. Sussex
Publishers, 29 Jan. 2009. Web. 17 Apr. 2017. https://www.psychologytoday.com/blog/mouse-man/200901/the-anatomy-posttraumatic-stress-disorder
Author:
Takeya J. Best
Edited
by: Aylin Marz, Ph.D.
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