to the disorder being meaningless, vague and a sham diagnosis, as it does not refer to any definable disease. Furthermore, throughout its history, many patients have been misdiagnosed with hysteria or conversion disorder when they had organic disorders such as tumours or epilepsy or vascular diseases. This has led to patient deaths, a lack of appropriate care and suffering for the patients. Eliot Slater, after studying the condition in the 1950s, stated: "The diagnosis of 'hysteria' is all too often a way of avoiding a confrontation with our own ignorance. This is especially dangerous when there is an underlying organic pathology, not yet recognised. In this penumbra we find patients who know themselves to be ill but, coming up against the blank faces of doctors who refuse to believe in the reality of their illness, proceed by way of emotional lability, overstatement and demands for attention... Here is an area where catastrophic errors can be made. In fact it is often possible to recognise the presence though not the nature of the unrecognisable, to know that a man must be ill or in pain when all the tests are negative. But it is only possible to those who come to their task in a spirit of humility. In the main the diagnosis of 'hysteria' applies to a disorder of the doctor–patient relationship. It is evidence of non-communication, of a mutual misunderstanding... We are, often, unwilling to tell the full truth or to admit to ignorance... Evasions, even untruths, on the doctor's side are among the most powerful and frequently used methods he has for bringing about an efflorescence of 'hysteria'". Much recent work has been done to identify the underlying causes of conversion and related disorders and to better understand why conversion disorder and hysteria appear more commonly in women. Current theoreticians tend to believe there is no single cause for these disorders. Instead, the emphasis tends to be on the patient's understanding and a variety of psychotherapeutic techniques. In some cases, the onset of conversion disorder correlates to a traumatic or stressful event. There are also certain populations that are considered at risk for conversion disorder, including people with a medical illness or condition, people with personality disorders or dissociative identity disorder. However, no biomarkers have yet been found to support the idea that conversion disorder is caused by a psychiatric condition. There has been much recent interest in