Thursday, April 27, 2017

How the Body and Brain Respond to PTSD

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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1.       ”Post-Traumatic Stress Disorder” National Institutes of Health. U.S. Department of Health and Human Services. Web. 17 Apr. 2017.
2.       "The Science Behind PTSD Symptoms: How Trauma Changes the Brain" World of Psychology. N.p., 11 Sept. 2015. Web. 17 Apr. 2017.
3.       "The Anatomy of Posttraumatic Stress Disorder" Psychology Today. Sussex Publishers, 29 Jan. 2009. Web. 17 Apr. 2017.
4.       Art by Anthony J. Silver.

Author: Takeya J. Best 
Edited by: Aylin Marz, Ph.D.

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