*Published online (Advances in Psychiatric Treatment) by Cambridge University Press: 02 January 2018. By Colm Owens and Simon Dein.
“Conversion disorders tend to be poorly understood and diagnosis can be difficult. In this article, we aim to clarify what conversion disorders are and how they can be distinguished from other psychiatric disorders that involve physical symptoms. Prevalence, prognosis and relationship to organic disease are controversial areas; we outline what is known about them and provide some historical context. Aetiological theories and management strategies are discussed, the latter with the aid of case vignettes.
All doctors have encountered patients whose symptoms they cannot explain. These individuals frequently provoke despair and disillusionment. Many doctors make a link between inexplicable physical symptoms and assumed psychiatric illness. An array of adjectives in medicine apply to symptoms without established organic basis – ‘supratentorial’, ‘psychosomatic’, ‘functional’ – and these are sometimes used without reference to their real meaning. In psychiatry, such symptoms fall under the umbrella of the somatoform disorders, which includes a broad range of diagnoses. Conversion disorder is just one of these. Its meaning is not always well understood and it is often confused with somatisation disorder. Our aim here is to clarify the notion of a conversion disorder (and the differences between conversion and other somatoform disorders) and to discuss prevalence, aetiology, management and prognosis…
Organic medical/neurological illness
Somatisation Multiple, recurrent and frequently changing physical symptoms over a lengthy period. Preoccupation with these symptoms, leading to marked distress in the patient: ‘I’ve got all these pains, why can’t they find out what’s wrong with me?’
Hypochondriasis Preoccupation with having one (or more) serious physical illness, despite evidence to the contrary: ‘I know I’ve got cancer, they just haven’t done the right test yet’.
Factitious disorder Intentional feigning of symptoms with unclear motivation: the patient does not know why they are doing it. Also known as Munchhausen’s syndrome.
Malingering Intentional feigning of symptoms with clear motivation: the patient does know why they are doing it.
In the first edition of the DSM (now known as DSM–I) (American Psychiatric Association, 1952), conversion disorder appeared as ‘conversion reaction’ (Box 2). In DSM–II (1968), it was grouped with dissociation disorder under the new diagnostic category of ‘hysterical neurosis’, a title echoing the early concept of ‘hysteria’ resulting from uterine disorder in women (see ‘Theories of conversion disorder’ below). Subsequently, conversion disorder was conceptualised as a disorder of the brain associated with disordered emotions. The transition within the DSM to a system that classified psychiatric disorders by clinical phenomenology rather than aetiology resulted in the elimination of ‘hysterical neurosis’ from DSM–III (American Psychiatric Association, 1980) and its replacement by ‘dissociation’ disorders and ‘conversion’ disorders. Conversion disorder was separated from dissociation disorder and categorised as a somatoform disorder. Thus, since 1980, the somatoform disorders and the dissociative disorders have been separate categories in the DSM. The characterisation of DSM somatoform disorders is by disturbances in physical sensations, or inability to move the limbs or walk, whereas DSM dissociative disorders involve involuntary disturbance in the sense of identity and memory.
…Conversion has been attributed to many different mechanisms. One influential theory, dating back to Ancient Greek physicians who thought the symptoms specific to women, invoked as their cause the wandering of the uterus (hustera), from which the word hysteria derives. The term conversion was first used by Freud and Breuer to refer to the substitution of a somatic symptom for a repressed idea (Freud, 1894). This behaviour exemplifies the psychological concept of ‘primary gain’, i.e. psychological anxiety is converted into somatic symptomatology, which lessens the anxiety and gives rise la belle indifference, where a patient seems surprisingly unconcerned about their physical symptoms. The ‘secondary gain’ of such a reaction is the subsequent benefit that a patient may derive from being in the sick role…”