CENTER ON BEHAVIORAL MEDICINE
Psychogenic: Research Article
(September 2004) Psychological Mechanisms of Medically
Symptoms: An Integrative Conceptual Model. Psychological
© 2004 by the American Psychological Association Vol. 130, No. 5,
ABSTRACT: Theories of medically unexplained illness based on the concepts of dissociation, conversion, and somatization are summarized. Evidence cited in support of these theories is described and the conceptual strengths and shortcomings of each approach are considered. It is argued that each of these approaches adds to the understanding of unexplained illness but that none is able to provide a comprehensive explanation of the phenomenon. An integrative conceptual model of unexplained illness based on cognitive psychological principles is then presented. This model attempts to combine existing theoretical approaches within a single explanatory framework, extending previous theory by explaining how compelling symptoms can exist in the absence of organic pathology. The clinical and empirical implications of the model are then considered.
This review has attempted to describe current theoretical models of medically unexplained symptoms and the research cited in their support. It is clear that research motivated by the concepts of dissociation, conversion, and somatization has added much to the understanding of unexplained symptoms. Nevertheless, it is clear that there are certain shortcomings—both empirical and conceptual—with existing approaches in this area. In particular, none of the available models is able to provide an adequate account of how subjectively compelling symptoms can persist in the absence of organic pathology. In this article, an integrative conceptual framework that attempts to address these shortcomings, and that explicitly endorses the idea that unexplained symptoms are subjectively real to the sufferer, has been described.
The proposed model is consistent with Janet's (1889, 1907) dissociation theory in its assertion that symptoms are caused by stored information in the cognitive system that disrupts the interaction between conscious and preconscious aspects of information processing. In line with conversion theory, the model suggests that this process is often driven by a defensive reaction that operates to reduce the individual's exposure to traumatic affect. Like somatization theory, the model identifies symptom-focused attention as central to the creation and maintenance of unexplained symptoms, and highlights the importance of catastrophic misinterpretation, illness beliefs, rumination and worry, illness behavior, negative affect, and personality features in this process. Although consistent with the concepts of dissociation, conversion, and somatization, the model extends existing theories in this area by reformulating them within a common explanatory framework that is based on cognitive psychological principles. In this way, the model attempts to place the current understanding of unexplained symptoms within the remit of everyday psychology, allowing for a more normalizing interpretation of this phenomenon. It is hoped that the model provides a useful scheme for organizing existing research and theory in this area, as well as an impetus for further research into unexplained symptoms and the development of more effective strategies for their treatment.
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