Fear Conditioning

Mowrer's two factor conditioning theory suggests that:

• The intensity of the traumatic incident is such that stimuli that were present at the time of the trauma (unconditioned stimulus) become associated with fear and arousal symptoms - An example of classical (Pavlovian) conditioning.
• Henceforth similar stimuli (now conditioned) trigger responses as if the trauma was recurring.
• Through stimulus generalization, a wide variety of stimulus bearing the slightest or even no resemblance to the actual traumatic stimuli become triggers of distress.
• Thus for obvious reasons the person tries to avoid all the distressing stimuli in the immediate and remote environment. Although it provides less distress, it is this avoidance behavior that maintains and reinforces the deep seated fear, preventing extinction and thus maintains the problem which we clinically elicit as PTSD.

Appraisals of the Traumatic Event

A similar traumatic experience might have different personal meanings for different people. Some are able to see trauma as a time limited terrible experience that does not necessarily have negative implications for the future. Unlike these people who are likely to recover quickly, those with persistent PTSD are characterized by excessively negative appraisals of the event. The nature of predominant emotional responses in PTSD depend on the particular appraisals, for example, appraisals concerning:

• danger lead to fear - no where is safe
• others violating personal rules lead to anger - others have not treated me fairly
• responsibility for the traumatic event lead to guilt or shame - it was my fault, I did something despicable
• loss leads to sadness - my life will never be the same again

In addition to appraisal of the traumatic event itself, negative appraisals of the initial PTSD symptoms - I am going mad; as well as perceived negative responses from other people - I have fallen down in their eyes; in the aftermath of trauma has often been found to distinguish between traumatized individuals with or without PTSD. 

Nature of Trauma Memories

It has been seen that PTSD patients have poor intentional recall of the traumatic event. Narratives which were initially fragmented and disorganized become elaborate and organized with successful treatment. This has led to the hypothesis that insufficient elaboration of the event and its meaning leads to the re-experiencing symptoms of PTSD. Ehlers and Clark thus proposed that the trauma memory is inadequately linked to its context in time, place and other autobiographical memories, hence even remotely similar stimuli can trigger of vivid memories and strong emotional responses, as if the event was happening right then.

Maintaining Behaviors

The course of PTSD often depends on the presence or absence of certain maintaining behaviors. Those with prolonged symptoms are seen to have either some or all of the following:

• Avoidance of reminders
• Suppression of thoughts and memories connected to the event
• Rumination
• Safety behaviors
• Dissociation
• Use of alcohol or drugs

These behaviors and cognitive strategies maintain PTSD in three ways:

1. Some behaviors directly lead to increase in symptoms e.g. thought suppression leads to paradoxical increase in intrusion frequency.
2. Other behaviors prevent changes in the problematic appraisal e.g. safety behaviors like not going outdoors after being assaulted might prevent change in the belief that one will be assaulted again if one goes out of the house.
3. Others  prevent elaboration of the trauma memory e.g. after a road traffic accident, avoiding thoughts about the same prevents the survivor from incorporating the fact that he did not die, and thus he keeps re-experiencing the fear of dying which he originally felt during the accident.

These are some of the psychological processes that have a causal and maintaining role in PTSD symptoms. The enumeration is far from exhaustive. It must be borne in mind that different combinations of theoretical models might be involved in different individuals. As intervention needs to be individualized and often depends on the precipitating and maintaining factors, care should be exercised in identification of the same.

 Next: PTSD - Aetiologic Biological Processes