Yule's, Williams, and Joseph's Integrated Psychosocial Model
Yule, Williams, and Joseph present what they call a multifactorial model of PTSD that includes numerous components from other models and combines them into a complex of interrelated variables. Perhaps, the easiest way to approach an understanding of their model is to first present it as shown in Figure 7.1.
To understand the model, begin with the traumatic event, and go clockwise through event cognitions, appraisals, emotional states, coping, appraisal with cognitions influenced by personality or memory representations, and the social environment, with a final state of either continued cycling or resolution.
This is a complicated model, and, perhaps, the best way to represent it is to simply define the components in a listwise fashion:
■ Event stimuli. A traumatic stressor.
■ Event cognitions. Mental representations that are either not available for conscious inspection or information is intentionally retrievable. These are the basis for reexperiencing symptoms of PTSD.
■ Appraisal cognitions. These are thoughts about the stressor information and memories it evokes. Its two forms are automatic thoughts associated with schemas and emotional states and reappraisals or conscious thinking through alternative meanings. This aspect reflects rumination and intrusive cognition.
■ Personality. An individual's schemas and personality characteristics that exert influence on both appraisals and cognitions about the event.
■ Emotional states. Emotional states that can also be appraised or reappraised.
■ Coping. This component includes any and all coping responses, such as avoidance, rumination, emotional suppression, and so on.
■ Environmental and social context. This component represents the context in which all of this takes place and the ongoing environmental stimuli that might serve to trigger a traumatic cognition.
In essence, what Yule's, Williams and Joseph's model is saying is that an event triggers a cognitive response that is determined by a person's personality and appraisal outcomes. Appraisal outcomes are determined by personality, emotion, and coping in a cyclical feedback loop. The environment and social context are both independent but are influenced by the person's coping responses. The model, although complex, takes a sophisticated approach in its attempt to capture all the components in PTSD etiology and how they interact with each other. What stands out is their focus on the interaction of each of the components and how they influence each other. This model is an excellent representation of the complexity of both PTSD specifically and psychological processes in general.
George Everly's Integrative Two-Factor Model
Everly's (1995) approach combines a biological and psychological explanation of PTSD. Its attempt at integration combines the core DSM-IV-TR symptom groups into a single psychophysiological construct. As one might discern from its title, there are two factors, conceptualized within a neurocognitive framework. A diagram of the model is shown in Figure 7.2.
Factor one consists of an underlying sensitized nervous system with three main features. The first feature involves the augmentation of excitatory neurotransmitters, such as norepinephrine, dopamine, and glutamate. The second feature involves a functional reduction in inhibitory neurochemicals, such as gamma-aminobutyric acid (GABA). The third and final feature involves changes in neural structure and intraneuronal functioning that biases the nervous system toward excitability, such as postsynaptic sensitivity or a reduction in neurotrans-mitter reuptake mechanisms. Ultimately, all of this results in an individual being in a state of extreme, chronic, and intense arousal. It is as if the nervous system is set, poised, and fixated in a state of alert, survival, and security.
Factor two refers to the hypersensitivity of the psychological components of the model. At the core of this factor is the underlying concept that human beings have as a basic need and are constantly striving toward an understanding and cognitive or mental grasp on their world and their self. What essentially happens is that a traumatic stressor or event results in a significant challenge and violation of a person's worldview and a subsequent inability to assimilate the new information into one's view of the world and one's view of oneself. Ultimately, as Maslow (1970) and Horowitz (1976) have stated, once a person's sense of basic safety and security is so significantly challenged or threatened, he or she becomes fixated on the task of trying to restore it, constantly seeking resolution or integration.
Bessel van der Kolk and McFarlane's Model
Bessel van der Kolk characterizes the range of Biopsychosocial consequences or responses to traumatic stress as a process of adaptation to trauma. Trauma can have at least three very large effects on an individual. First problems with regulation of affective states, including problems with anger and anxiety, can arise. Victims overreact to emotional stimulation and may experience anhedonia and numbing as a consequence.
Factor one: Neurologic hypersensitivity—A pathognomonic propensity for or status of limbic system neurologic arousal
Factor two: Psychologic hypersensitivity—A pathognomonic inability to assimilate the traumatic event into the extant worldview
A second consequence leads to vulnerability to engage in pathological attempts at self-regulation, such as self-mutilation, Eating Disorders, or Substance Abuse. In an individual's attempts to regain control, he or she may resort to unhealthy means to do so. There is a breakdown in an individual's capacity to consider a range of actions before acting. They may have problems with fantasy and playing with options. van der Kolk and McFarlane (1996) state that fantasizing may allow previously blocked memories to emerge. In order to avoid this, emotions are restricted and one's fantasy life is limited. This leads to the avoidance of recollection. They may also have significant difficulty sorting out important stimuli from unimportant stimuli, finding themselves unable to filter what is unimportant and reacting by shutting down and shutting out stimuli. This leads to less contact with daily life and a subsequent increase in ruminating about the trauma.
"What distinguishes people who develop PTSD from people who are merely temporarily distressed is that they organize their lives around the trauma," according to van der Kolk and McFarlane (1996, p. 6).
Third, extreme arousal is accompanied by dissociation, alexithymia, somati-zation, and a failure to establish a sense of security and safety, leading to char-acterological issues with self-efficacy, shame, self-hatred, dependence, and isolation and relationship issues. One's attachment security is considered a primary defense against trauma-induced pathology. This is seen as especially important with traumatized children, and research has shown that the quality of the parental bond may be the most important factor in whether PTSD develops (McFarlane, 1987a, b, c, d) in kids.
Victoria McKeever and Maureen Huff (2003) have attempted to construct a single model to address the various influences contributing to the development of PTSD. They reason that because the majority of persons exposed to traumatic stressors do not develop PTSD, this variation can be accounted for by the presence or lack of certain etiological risk factors per individual. They categorize all the various etiological risk factors into three large groups: residual or situation stress, ecological diatheses, and biological diatheses. They state that all of these mutually influence each other. Figure 7.3 represents the model
The residual category represents the primary pathway for the development of PTSD, being augmented or attenuated by the other two groups of etiological diatheses and biological diatheses. A diathesis can be conceptualized as a relatively dormant set of risk factors that blossom, if you will, when triggered by a sufficient stimulus. McKeever and Huff (2003) make an important point about the relationship between intensity of a stressor and the level of diatheses present in an individual. They call this the psychological break point, the point at which PTSD emerges. Basically, the higher the degree of premorbid risk factors or diatheses is present, the smaller a stressor has to be to push someone toward
PTSD and vice versa. Residual stress was defined by Foy, Donahoe, and Carroll (1987) as a negative psychological condition resulting from the experience of a traumatic event. The more severe the trauma, the higher the level of residual stress. The diagnostic qualifiers of intense fear, helplessness, and horror capture this feature of the model in the DSM-IV-TR.
As was discussed in Chapter 4, research has demonstrated a great number of risk factors for the development of PTSD. McKeever and Huff's (2003) model addresses nonbiological risk factors in the ecological component of their model. A history of childhood abuse, being a member of a discriminated against group, poor social support, or personality factors are all examples of ecological diatheses.
Finally, biological diatheses such as altered neuronal functioning, altered brain volume, and altered hormone functioning are the final key component in this triarchic diathesis stress model. (For more on the various biological complications resulting from trauma, see Chapter 3.)
Wilson, Friedman, and Lindy (2001) have proposed a complex model of PTSD that attempts to go beyond the DSM-IV and the core symptoms of PTSD to capture the multidimensional aspects of the disorder as it affects individuals across a wide range of biopsychosocial areas. At the core of their model rests Bruce McEwan's concept of allostatic load. Allostasis refers to an organism's regulation of biopsychosocial functioning in the face of stress and strain, or allostatic load. Many of us are familiar with the concept of homeostasis, in which an organism attempts to maintain a balance between internal and external or ecological and environmental demands. Similarly, allostasis works to maintain balance through similar mechanisms of input and feedback but more specifically when impinged or impressed upon by significant load.
Ecological Diatheses Biological Diatheses Residual Stress PTSD
Ecological Diatheses Biological Diatheses Residual Stress PTSD
1. Emotional regulation.
2. Cognitive processes and information processing at different levels of consciousness.
3. Motivational predispositions, such as need-based, goal-directed behaviors.
4. Psychobiological processes (i.e., fight-or-flight responses).
5. Ego defenses, coping patterns, and systems of belief, meaning, and spirituality.
In an attempt to represent PTSD as a "multidimensional construct of stress response syndromes," Wilson et al. (2001, p. 30) created what they call the tetra-hedral model, a holistic representation of an organism with five symmetric posttraumatic states. For a visual representation of the model, the reader is referred to Chapter 2 in Treating Psychological Trauma and PTSD (Wilson 2001). This figure is far too complex and intricate to be visually represented here, but a verbal description of the model follows.
The tetrahedral model is essentially a five-sided figure with a multilayer embedded system within it that represents the interactions of the various components of ego and psychobiological processes. There are three basic dimensions of psychological functioning outlined: the entire organism; the triad of core PTSD symptoms per the DSM-IV; and internal ego processes, including ego states, self-structure, and identity configuration. Internal ego processes directly impact somatic and integrated biological-organismic system functioning. Post-traumatic Stress Disorder symptoms in turn influence ego processes, cognition, self-reference, ego-identity, and the operation of the ego-defense mechanisms. The psychobiological processes are represented in these ego states, ego processes, elements of self-structure, individual persona, and the "entire range of dynamics in personality processes"(Wilson et al., 2001, p. 34). An easy way to approach this model is to think of the ego functions, personality characteristics, cognitions, emotional responses, and interpersonal functioning of a person with PTSD as representing underlying neurobiological alterations. In many ways, as they themselves state, their model represents a good attempt at a mind-body model of PTSD. Perhaps that is what they meant by the holism component of their model's title? In many ways, this model is not an etiological account as much as it is a solid attempt to bring together the psychological and biological knowledge bases within the PTSD research and clinical tradition.
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