Conversion Disorder

Conversion disorder is a neurosis marked by the appearance of physical symptoms such as partial loss of muscle function without physical cause but in the presence of psychological conflict. Symptoms include numbness, blindness, paralysis, or fits without a neurological cause. It is thought that these problems arise in response to difficulties in the patient's life, and conversion is considered a psychiatric disorder in the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV).

Formerly known as "hysteria", the disorder has arguably been known for millennia, though it came to greatest prominence at the end of the 19th century, when the neurologists Jean-Martin Charcot and Sigmund Freud and psychiatrist Pierre Janet focused their studies on the subject. The term "conversion" has its origins in Freud's doctrine that anxiety is "converted" into physical symptoms. Though previously thought to have vanished from the west in the 20th century, some research has suggested it is as common as ever.

The DSM-IV classifies conversion disorder as a somatoform disorder while the ICD-10 classifies it as a dissociative disorder.