Functional MRI and transcranial magnetic stimulation data are helping to explain the aetiology of conversion disorder.

Conversion disorder occupies some unusual niches within the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).1 It is one of the very few conditions where the manual makes reference to aetiology, invoking emotional conflict or other stressors as an initiating or exacerbating factor in the symptom production. Furthermore, the typical symptoms of conversion disorder, like loss of sensation, paralysis or, as in the case reported by Chastan et al (see page 94), aphonia, are deemed “pseudoneurological.”2 It is for these reasons that conversion disorder is …