Conversion disorder (formerly "hysteria") is a psychosomatic illness. The patient will present with any of a number of neurological symptoms that generally will not disappear with treatment. Unlike Munchausen syndrome, the patient is not deliberately feigning the symptoms and is of the genuine belief that they are ill. It is generally caused by severe stress or personal conflict. It can mimic many other illnesses, some of them quite severe. Conversion disorder can affect a large number of people at once, particularly in very stressful situations, (colloquially "mass hysteria").
Diagnosis of conversion disorder is a three part process:
- All other organic causes for the symptoms must be ruled out;
- It must be established that the patient is not feigning the symptoms; and
- A psychological mechanism for the onset of symptoms must be established.
Conversion disorder can usually be treated by explaining to the patient how the symptoms arose and reassuring them. However, severe cases can either be treated with physiotherapy or by treating underlying depression or anxiety.
In Airborne, House deals with a plane full of people convinced they are getting ill from an unknown illness, including his boss Cuddy. He finally manages to convince the passengers they are not really ill by suggesting a symptom they might develop (a shaking left hand - which was not a symptom of the suspected illness) and watching many of the passengers develop it. The passengers were worried that a genuinely sick passenger had a contagious disease.