PTSD

Relevant work done in this context

• Post-Traumatic Stress Disorders & Virtual Reality

A definition

A ‘Post-Traumatic Stress Disorder’ is considered one of the twelve different types of anxiety disorders. Hence, before giving the definition of a PTSD, it is useful to look at the characteristics of an ‘anxiety disorder’ first.

According to DSM-IV (Diagnostic and Statistical Manual of Mental Disorders IV, 1995) a generalized anxiety disorder is characterized by:

• anxiety occurring persistently

• excessive and hard to control worry

• feelings of uneasiness.

Anxiety and feelings of uneasiness are normal human reactions when someone is in a stressful situation. Sometimes anxiety even results in better performance (Raudis & Yustitskis, 2008), as seen in the Yerkes-Dodson law graph in figure 1. However, when this feeling becomes excessive and influences a person’s lifestyle, it is, like most other mental disturbances, considered a disorder. A very noticeable change in one’s lifestyle is the avoidance of certain activities, people and places (Diagnostic and Statistical Manual of Mental Disorders IV, 1995).

This definition covers anxiety disorders in general. DSM-IV provides the following description for a PTSD:

“Posttraumatic Stress disorder is characterized by the re-experiencing of an extremely traumatic event accompanied by symptoms of increased arousal and by avoidance of stimuli associated with the trauma.” (Diagnostic and Statistical Manual of Mental Disorders IV, 1995)

This definition already specifies certain symptoms which make a PTSD different compared to other (anxiety) disorders. Symptoms of a PTSD can be distinguished by three different symptom clusters (Paul M. G. Emmelkamp, et al., 1995). Each cluster is related to one of the following:

• Re-experiencing,

• Avoidance

• Arousal

These symptoms occur after the person has been exposed to a specific kind of stressor. However, not everyone will experience these symptoms immediately after the event. In many cases the symptoms occur days or even months after the stressor. What are the criteria for these symptoms and what is considered a traumatic event? Also, in which ways does the person re-experience these events over and over again?

Criteria

The traumatic event or ‘stressor’ has to be of an extreme nature (Paul M. G. Emmelkamp, et al., 1995). Of course this statement is somewhat subjective, as one person is able to handle a specific stressor while others can not. Also, not everybody who experiences a traumatic event will react the same way (Diagnostic and Statistical Manual of Mental Disorders IV, 1995; Paul M. G. Emmelkamp, et al., 1995). The stressor is usually of human design (kidnapping, terrorist attack, personal assault, etc.), but also exposure to natural disasters (volcano eruption, tsunami) can result in a PTSD. In both cases it is clear that these kinds of events are outside the bounds of “normal”, everyday experiences. The stressors mentioned here all have one thing in common: they can pose a serious threat to one’s life or environment. DSM-IV (Diagnostic and Statistical Manual of Mental Disorders IV, 1995) specifies these traumatic stressors as one of the criterion of PTSD. The stressor must suit at least one of the following:

• Experience of an event which involves a serious injury or actual or threatened death. • Witnessing an event involving death or injury of other persons. • Learning or hearing about unexpected or violent death, harm, threat of death or injury by a family member or close relative.

This criterion is only concerned with the possible cause of a PTSD. Not everyone will develop a PTSD when confronted with one of the above mentioned stressors. Therefore more criteria are needed to cover the response and possible symptoms following a traumatic event.

DSM-IV (Diagnostic and Statistical Manual of Mental Disorders IV, 1995) states that a person’s response to a stressor must involve fear, helplessness or horror. Next to this response, people who have developed a PTSD also experience certain symptoms related to the trauma. One such a symptom is the persistent re-experiencing of the stressor, as mentioned in the definition of a PTSD. There are various ways this symptom can occur. DSM-IV describes these as a new criterion:

• Recurrent recollections of the event. This includes thoughts, perceptions and images. Not only when the person is awake, but also when the person is asleep. • The person feels or thinks as if the traumatic event recurs. • The person is distressed when exposed to various stimuli related to the traumatic event. • Physiological reactivity on exposure to the stimuli mentioned in the previous criterion.

Strongly related to this symptom is the persistent avoidance of specific stimuli. Of course the avoidance must occur after the exposure of the stressor. DSM-IV (Diagnostic and Statistical Manual of Mental Disorders IV, 1995) states that avoidance is one of the criteria related to PTSD and that at least three of the following indicators should be true.

• Avoidance of feelings, thoughts or conversations associated to the trauma • Avoidance of activities, places or people which may trigger recollections of the trauma • The inability to recall an important part of the traumatic event • Lost interest in certain activities • Feelings of detachment from friends or family members • Limited experience of feeling or emotion • Only thinking about the near future

Another important symptom and criterion is the increase of arousal of a person. This may lead to difficulties sleeping and concentrating. The increased arousal can also lead to sudden outbursts of anger and hyper vigilance (Diagnostic and Statistical Manual of Mental Disorders IV, 1995). The duration of these symptoms, including the re-experiencing and avoidance of the stressor, must be longer than one month.

Fear structure and emotional processing theory

Some of the treatments which will be described in the next chapter, such as imaginal exposure, are strongly related to the emotional processing theory by Foa and Kozak (E. B. Foa & Kozak, 1986). This theory states that patients with a PTSD have developed so-called ‘fear structures’ consisting of information about:

• Stimuli associated with a traumatic event • (Their) behavioural responses • Meaning representations

The stimuli were already mentioned in the previous paragraph. People exposed to a stressor will remember facts about associated stimuli. For example a vehicle that exploded after it hits another car or seeing a comrade die by a mine.

Not only information about the stimuli is remembered but also facts about the behavioural response of the person at that time. For example a racing heart beat and perspiration.

And the last aspect is information about the meaning representation of the traumatic event. The meaning representation of a certain event can, of course, differ from person to person. The representation is strongly related to the stressors and criteria mentioned in the first part of the previous paragraph. One can, for example, associate an explosion to death or death of relatives.

Some treatments are based on activation of this fear structure using repeated exposure and adding new learning elements while anxiety is reduced (E. B. Foa & Kozak, 1986; E. B. Foa, Riggs, Massie, & Yarczower, 1995). Studies (E. B. Foa, et al., 1995) have shown that there is a correlation between activation of this fear structure and improvement in treatment. The treatments related to this theory will be discussed in detail in the next chapter.