Behavior

Amnesic barrier

Figure 2 Generation of an unexplained symptom through the dissociation of a memory from consciousness.

Amnesic barrier

Figure 2 Generation of an unexplained symptom through the dissociation of a memory from consciousness.

giving rise to it. By this account, therefore, hysterical symptoms serve an important psychological purpose (i.e., defense), with the discharge of emotional energy representing the primary gain from symptoms. In this model, symptoms generated by the process of conversion correspond to sensations present at the time of the underlying trauma, or they are a symbolic representation of it.

Although more than a century old, the theoretical analyses of hysteria offered by Janet, Breuer, and Freud continue to influence nosology, theory, and clinical practice concerning medically unexplained symptoms. Several lines of evidence provide information concerning the validity of the dissociation and conversion models.

1. Attention

Many theoretical models have endorsed Janet's idea that somatoform illness involves an alteration in attention that prevents processed information from entering conscious awareness. Recent electrophysio-logical research indicating that conversion disorder is associated with normal early evoked potentials but a deficit in the later P300 component provides strong support for such a view. Several cognitive and psychophysiological studies have also found evidence for a diffuse attentional deficit in individuals with conversion symptoms, with patients showing decrements on tasks assessing vigilance, habituation, cognitive flexibility, set shifting, and mental transformation. However, the precise nature of the atten-tional deficit underlying conversion remains unclear; further research is required if it is to be described in greater detail.

2. Hypnosis

Janet's proposal that hysterical and hypnotic phenomena share similar psychological mechanisms also continues to attract support. In line with this hypothesis, many studies have shown that individuals with somatoform and conversion illness tend to exhibit high levels of suggestibility. Moreover, recent imaging studies using positron emission tomography have provided limited evidence indicating that similar neuroanatomical substrates may be involved in both conversion and hypnotic paralysis. Currently, however, the link between hypnosis and somatoform illness is still largely theoretical; further empirical evidence based on larger sample sizes is required before firm conclusions can be drawn in this regard.

3. Psychological Trauma

The view that unexplained symptoms are related to traumatic experiences, central to both the dissociation and the conversion models, has also been widely adopted. Indeed, current diagnostic criteria require that clear psychosocial precipitants be present for a diagnosis of conversion disorder or somatoform pain disorder. Although there is substantial evidence to suggest that many instances of somatoform illness are either preceded by psychosocial precipitants or associated with significant early trauma, it is clear that traumatic precipitants are absent in many cases. Moreover, many traumatized individuals with soma-toform illness have not experienced amnesia for their trauma, and symptom resolution is not guaranteed by the recovery of previously forgotten traumatic memories. As such, trauma cannot play the primary pathogenic role in the generation of medically unexplained symptoms suggested by Janet, Breuer, and Freud, although it is clearly relevant in many instances.

Was this article helpful?

0 0
Hypnosis Plain and Simple

Hypnosis Plain and Simple

These techniques will work for stage hypnosis or hypnotherapy, however, they are taught here for information purposes only. After reading this book you will have the knowledge and ability necessary to hypnotise people, but please do not practice hypnosis without first undergoing more intensive study.

Get My Free Ebook


Post a comment