Chapter 7. The Mechanism of Dissociation (2) Conversion ------ Dissociation on the Physical Level (2)

PTSD and dissociative disorder are two representatives of trauma-related mental disorders. Clinicians who engage in these disorders form their own international organization, i.e., ISSTD (International Society for the Studies of Trauma and Dissociation) and ISTSS (International Society for Traumatic Stress Studies). Both of them have their Japanese branch or “component group”. These two organizations are friendly and cooperative to each other, but they are separate nonetheless, as though they belong to tacitly divided two camps: one for PTSD and the other for dissociative disorder. Their focus for trauma-related somatic symptoms is somehow different. They deal with two different prototypical symptoms.
Trauma’s effect on the physical level - two prototypes.
When threatened by the enemy, animals tend to show very primitive and short-circuited reaction. They are forced to make a choice whether to fight the enemy or get away from it. It was eighty years ago that Walter Cannon came up with the concept “fight or flight response” (Cannon, 1929). Since that time, this fight or flight has been a convincing model about animal reaction to threat and intrusion.
Cannon WB: Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Research Into the Function of Emotional Excitement, 2nd ed. New York, Appleton-Century-Crofts, 1929
As the studies on trauma progressed, a more precise model has been proposed. Bracha et al (2004) asserts that in fact, a few more components should be added to the model of fight or flight response in order to make this model more applicable to the real response to the treat. More precisely, there are two other Fs (freeze and fright) to be added.
According to Bracha, et al., animal’s initial response when it faces the enemy is freeze response before fight or flight occurs. This response is well known among animals. When they are under threat, they "stop, look, and listen" in order to avoid being caught. Fight or flight response is mobilized after this stage. (By the way, Bracha et al. states that the natural order is rather flight or fight, rather than fight or flight. which makes a lot of sense.)
Cannon, W. (1915) Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Researches into the Function of Emotional Excitement, Appleton, New York.
Bracha, H.S., Ralston, TC. (2004) Letter Does "Fight or Flight" Need Updating? Psychosomatics 45;448-449.
However, there could be another step which can occur instead of fight or flight. This is “tonic immobility” which is also referred to as “fright”. Tonic immobility corresponds to “playing dead” and by this reaction, the enemy gets off guard and loosens its grips (to be confusing enough, in child psychology, fright is also called freezing, according to Bracha, et al).

The reaction which corresponds to this tonic immobility is often seen in lower animals such as insects or reptiles, and it is considered as a prototype of dissociation（Schmahl, Bohus, 2007). Tonic immobility occurs at the moment that there is a contact with the enemy.



 4 Fs as a prototypical threat response



Schmahl, C., Bohus, M. (2007) Translational Research Issues in Dissociation. In Eric Vermetten E, Dorahy MJ, Spiegel (Ed.) D, M.D. Arlington, Va., American Psychiatric Publishing, Washington DC.