A psychological disorder characterized by physical symptoms for which no physiological cause can be found.
This condition was first described by Sigmund Freud as conversion hysteria because it involved the conversion of a repressed emotional problem to a physiological form. Today, conversion reaction is classified as a somatoform disorder in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV ).
Conversion reaction is a very rare condition, accounting for about 2 percent of all psychiatric diagnoses, and usually first appears during adolescence or early adulthood, generally when an individual is under severe stress. Symptoms tend to be both specific and severe, and generally interferes with daily activities. A conversion disorder may serve as a way for a patient to avoid activities or situations associated with a source of emotional conflict or even shut down conscious awareness of the conflict itself. Another source of "secondary gain" is the attraction of attention, sympathy, and support that the patient may need but is unable to obtain in other ways.
Some of the most common symptoms of conversion disorder are paralysis, blindness or tunnel vision, seizures, loss of sensation, and disturbance of coordinated movements, such as walking. Other physical complaints include tremors, abdominal pain, and speech impairments such as aphonia, the inability to speak above a whisper. Sometimes a person will experience anesthesia in only one part of the body, such as "glove anesthesia," which affects the hand only up to the wrist, although such a problem could have no physiological origin since there is no cut-off point between the nerves of the hand and arm. Symptoms may also involve the endocrine glands or autonomic nervous systems. If the symptoms of a conversion disorder are prolonged, they may produce physiological damage by interrupting the normal functioning of the body, and psychological damage by inducing excessive dependence on family members and other persons.
Freud, Sigmund. The Standard Edition of the Complete Psychological Works of Sigmund Freud. London: Hogarth Press, 1962.
——-. Dora: An Analysis of a Case of Hysteria. New York: Collier, 1963.