• conversion disorder

The article by Stone et al (this issue, p 591– 596)¹ addresses the natural history of a disorder with many names, none satisfactory. Functional, hysterical, psychogenic, medically unexplained, dissociative, conversion—all the names for this disorder have their faults. Yet the disorder is common, poses a management problem for doctors, and carries a poor prognosis. What is wrong with these patients?

What is now clearly known not to be wrong is the occult presence of a neurological disorder. Several follow up studies, this one included, show that the rate of erroneous diagnosis is low; neurological disease is not being missed when conversion disorder is diagnosed. Techniques of neurological examination that allow recognition of non-organic manifestations have been described,² although patients with organic disease may—because of suggestibility and the “demand characteristics” of the setting, generate non-organic signs if called on to do so by inappropriate examination.³

The follow up studies also show that most patients with conversion disorder have persisting, or remitting and relapsing, somatic symptoms. In addition, they have impairment of psychological and social functioning outside the sphere of medically unexplained somatic symptoms. For example, they often have mood disorders, self-injurious behaviour, dissociative symptoms, and interpersonal difficulties.

We have several clues about the fundamental nature of the disorder. Firstly, many of the patients have coexisting organic brain disease. Secondly, many have depressive disorders at the time of presentation with medically unexplained somatic symptoms. These facts point to the possibility of disruption of personality function by brain disease or by reversible abnormalities of brain state. Thirdly, however, many of the patients experienced sexual or physical abuse in childhood. This in itself, and as a proxy for widespread abnormality of the childhood environment, indicates that developmental factors are commonly implicated in the personality disturbance that gives rise (at times only intermittently) to conversion symptoms as well as (often persistently) to other failures of psychosocial functioning.⁴ As is always the case with personality disorder, heritable temperamental factors are likely to be relevant to vulnerability as well.⁵ In addition, patients often adduce the presence of contemporary “stress” in the origin of the symptoms. The evaluator strains to discover the actual direction of the causal arrow between personality dysfunction and chaotic or stressful life events. In Cloninger’s words, “the development of a conversion or somatization disorder occurs as part of a complex adaptive process involving non-linear interactions among multiple contributing factors”.⁵

In summary, conversion disorder appears to be a disorder of affect regulation and symbolisation, in which somatic experiences and complaints serve to represent and convey emotional distress, a purpose to which they are poorly suited. Ideally, the management of these patients centres on the formation of a treatment relationship not to catch the patient out but to allow exploration of areas of the patient’s life outside the presenting symptoms and construction of a plan to reduce distress (including focused treatment of commonly coexisting depressive disorder), and to develop alternative ways of seeking attention and assistance for distress.