Introduction
Post traumatic stress disorder (commonly referred to simply as PTSD) is an anxiety disorder caused by a traumatic event which has happened to someone. Not every person who has had a traumatic experience will develop PTSD. It is characterized by flashbacks to the incident, nightmares, and extreme anxiety (hyperarousal). Recently many theories have related neurology to the likelihood of a person with a history of trauma developing PTSD. This paper will delve further into our understanding of the condition, and what particular areas of the brain have to do with it.
Post Traumatic Stress Disorder
Post traumatic stress disorder can develop from any traumatic experience, especially if it was uncontrollable or unexpected. A person can develop it without having actually been involved in the situation. In many cases, witnesses are as likely to have PTSD as those who were technically affected. People with PTSD often feel that they are in danger even much after that danger has passed. This happens when the ‘fight or flight’ reaction is somehow damaged. Sufferers often relive the experience in their imaginations. This can take the form of dreams or intrusive thoughts. They often avoid thinking about the situation, and feel as if their future will be cut off because of it (www.ptsdassociation.com). The sorts of situations which can lead to PTSD are most often ones of combat or war. Of the 2.8 million survivors of the Vietnam war, 480 thousand have full PTSD. Another 350 thousand have partial PTSD. However, there are many other traumas that can also lead to it, including natural disasters, automobile accidents, muggings, etc.
Neurology
There are three parts of the brain which have been proven to have relation to the occurrence of PTSD. The first two that will be discussed are the prefrontal cortex and the hippocampus. The prefrontal cortex is related to decision making, social and cognitive behaviour, and personality expression. The hippocampus is related to memory and orientation. Abnormalities in these areas do not necessarily make it more likely that the person will have PTSD. For example, when one damages their prefrontal cortex, it actually makes them less likely to get the disorder. However, in the case of the hippocampus, a reduction in size is shown to have direct interaction with the likelihood of the average veteran of the Vietnam war having it. Oddly, these findings were not present in people involved in a plane crash in 1988. (www.wikipedia.org)
AMYGDALA
The third part of the brain related is the amygdala. The correlations here are more complex and more understood than those of the prefrontal cortex and hippocampus. The amygdalae are two groups of neurons, commonly described as almond shaped, shown to be related to memory and emotions. As with the hippocampus, a smaller amygdala will make a person more like to get PTSD. It is unclear whether the unusual size of an amygdala causes the disorder or is a product of it.
The amygdalae are commonly referenced in the field of fear conditioning. Fear conditioning is, as defined by wikipedia, ‘ a behavioral paradigm in which organisms learn to predict aversive events’. What this basically means is that living things are conditioned to predict uncomfortable events. This is a type of classical conditioning and is important because these organisms can use the conditioning to avoid danger from experience. We know that the amygdala is related to fear conditioning because when it is deactivated or removed it can prevent expression and conditioning. (www.wikipedia.org) This is further related to PTSD because it has been theorised that during extreme stress, fear can circumvent the hippocampus. This will lead to the fear being stored in the form of images or stomatically. The images can return without cognitive intention as flashbacks, key to PTSD.
We know that it is related to fear. In a genetic condition called the Urbach-Wiethe disease, the patient has focal bilateral amygdala lesions. People with this condition are said to have no fear at all. We also know that it is related to memory consolidation. While long term memory is not stored in the amygdala nor is it technically part of the learning process, its role in memory consolidation is essential. It regulates other parts of the brain while they are the ones taking part in the actual consolidation. Since the amygdala is partially in control of emotion, mediating it, and emotion is innately related to the strength of memories, the amygdala is in this way also indispensable to PTSD.
So although the relations between PTSD and the prefrontal cortex, the hippocampus, and the amygdala in particular are less understood than perhaps they ought to be, it is undeniable that unusual circumstances of any and all of them have relation to the disorder and that these findings will invariably lead experts towards better understanding and treatment of it.
Post traumatic stress disorder (commonly referred to simply as PTSD) is an anxiety disorder caused by a traumatic event which has happened to someone. Not every person who has had a traumatic experience will develop PTSD. It is characterized by flashbacks to the incident, nightmares, and extreme anxiety (hyperarousal). Recently many theories have related neurology to the likelihood of a person with a history of trauma developing PTSD. This paper will delve further into our understanding of the condition, and what particular areas of the brain have to do with it.
Post Traumatic Stress Disorder
Post traumatic stress disorder can develop from any traumatic experience, especially if it was uncontrollable or unexpected. A person can develop it without having actually been involved in the situation. In many cases, witnesses are as likely to have PTSD as those who were technically affected. People with PTSD often feel that they are in danger even much after that danger has passed. This happens when the ‘fight or flight’ reaction is somehow damaged. Sufferers often relive the experience in their imaginations. This can take the form of dreams or intrusive thoughts. They often avoid thinking about the situation, and feel as if their future will be cut off because of it (www.ptsdassociation.com). The sorts of situations which can lead to PTSD are most often ones of combat or war. Of the 2.8 million survivors of the Vietnam war, 480 thousand have full PTSD. Another 350 thousand have partial PTSD. However, there are many other traumas that can also lead to it, including natural disasters, automobile accidents, muggings, etc.
Neurology
There are three parts of the brain which have been proven to have relation to the occurrence of PTSD. The first two that will be discussed are the prefrontal cortex and the hippocampus. The prefrontal cortex is related to decision making, social and cognitive behaviour, and personality expression. The hippocampus is related to memory and orientation. Abnormalities in these areas do not necessarily make it more likely that the person will have PTSD. For example, when one damages their prefrontal cortex, it actually makes them less likely to get the disorder. However, in the case of the hippocampus, a reduction in size is shown to have direct interaction with the likelihood of the average veteran of the Vietnam war having it. Oddly, these findings were not present in people involved in a plane crash in 1988. (www.wikipedia.org)
AMYGDALA
The third part of the brain related is the amygdala. The correlations here are more complex and more understood than those of the prefrontal cortex and hippocampus. The amygdalae are two groups of neurons, commonly described as almond shaped, shown to be related to memory and emotions. As with the hippocampus, a smaller amygdala will make a person more like to get PTSD. It is unclear whether the unusual size of an amygdala causes the disorder or is a product of it.
The amygdalae are commonly referenced in the field of fear conditioning. Fear conditioning is, as defined by wikipedia, ‘ a behavioral paradigm in which organisms learn to predict aversive events’. What this basically means is that living things are conditioned to predict uncomfortable events. This is a type of classical conditioning and is important because these organisms can use the conditioning to avoid danger from experience. We know that the amygdala is related to fear conditioning because when it is deactivated or removed it can prevent expression and conditioning. (www.wikipedia.org) This is further related to PTSD because it has been theorised that during extreme stress, fear can circumvent the hippocampus. This will lead to the fear being stored in the form of images or stomatically. The images can return without cognitive intention as flashbacks, key to PTSD.
We know that it is related to fear. In a genetic condition called the Urbach-Wiethe disease, the patient has focal bilateral amygdala lesions. People with this condition are said to have no fear at all. We also know that it is related to memory consolidation. While long term memory is not stored in the amygdala nor is it technically part of the learning process, its role in memory consolidation is essential. It regulates other parts of the brain while they are the ones taking part in the actual consolidation. Since the amygdala is partially in control of emotion, mediating it, and emotion is innately related to the strength of memories, the amygdala is in this way also indispensable to PTSD.
So although the relations between PTSD and the prefrontal cortex, the hippocampus, and the amygdala in particular are less understood than perhaps they ought to be, it is undeniable that unusual circumstances of any and all of them have relation to the disorder and that these findings will invariably lead experts towards better understanding and treatment of it.