Conversion and dissociation disorders

Christopher Bass

in New Oxford Textbook of Psychiatry

Second edition

Published on behalf of Oxford University Press

Published in print February 2012 | ISBN: 9780199696758
Published online October 2012 | e-ISBN: 9780191743221 | DOI:
Conversion and dissociation disorders

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Of all the disorders characterized by symptoms in the absence of disease, conversion disorders are perhaps the most difficult to explain. How, for example, can one explain functional blindness or a loss of function of both legs in the absence of conspicuous organic disease? The ancient Greeks recognized that if we suffer emotional disturbance as a result of some serious stress (such as personal injury or bereavement), this causes a change in the nervous system which leads in turn to symptoms in different parts of the body according to the underlying pathophysiology. Nineteenth century neurologists made significant advances when they identified specific ideas at the root of the symptoms. In the early nineteenth century Collie also observed that the significance of, and attention to, a symptom or set of symptoms may depend more on what they mean (or their value) to the individual than on the biological underpinnings of the symptom itself. Spence has recently argued that the problem in hysterical motor disorders is not the voluntary motor system per se: rather, it is in the way that the motor system is utilized in the performance (or non-performance) of certain willed, chosen, actions. This model invokes a consciousness that acts upon the body and the world. By contrast, the psychodynamic (‘conversion’) model, which Freud introduced and which held sway for most of the twentieth century, invokes an unconscious mechanism ‘acting’ independently of consciousness, to interfere with voluntary movement. Spence has further argued that hysterical paralyses are maintained not by unconscious mechanisms, but by conscious processes. The maintenance of these symptoms requires the patient's attention, a characteristic of higher motor acts; the paralyses break down when the subject is distracted, consciousness is obtunded, or when it (the ‘paralyses’) is circumvented by reflexive motor routines. Hysterical paralyses, Spence avers, are quintessentially disorders of action (or inactions), which the patient disavows, when faced with some overwhelming situation, which threatens the identity of the self. One regrettable development of psychiatry's adoption of Freudian theory was the fracture in communication between the disciplines of psychiatry and neurology, which has only recently been restored by the sort of collaborative research currently being carried out by neurologists and psychiatrists. In the last decade there have also been exciting advances in neuroimaging, which have stimulated research into the neurophysiology of hysteria, and these will be described later. This chapter will also emphasize contemporary approaches to management of these difficult clinical problems.

Chapter.  8873 words.  Illustrated.

Subjects: Psychiatry

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