Hysterics suffer from reminiscences.
-Breur and Freud, Studies in Hysteria, 1895

People can have symptoms of disease for all sorts of reasons, but there is a small but significant subgroup of patients for whom no physical cause serves to explain their symptoms. When there is a presumed psychological explanation for the problem, this is called a somatoform disorder. The most classical and specific of the somatoform disorders is called conversion disorder - so called because psychological stressors are converted into physical symptoms.

Somatoform disorders in general - and conversion disorder in particular - used to be known as hysteria. The word is derived from the Greek word for uterus, because it was presumed by the Greeks that the problem originated there. It follows from this that for many years conversion disorder was presumed to be exclusively a female disorder - which isn't true, although it is more commonly diagnosed in women than in men. This theory led to early and misguided treatment recommendations ranging from masturbation to hysterectomies.

The presentation of conversion disorder can vary markedly from one person to the next, and the DSM-IV¹ recognises four subtypes:

• Motor symptoms - People with this type of conversion disorder may have:

  • paralysis or weakness, often of a specific limb,
  • coordination or balance problems, or
  • swallowing problems, a persistent lump in the throat sensation, or voice loss.

• Sensory symptoms - People with this type of conversion disorder may have:

  • blindness or other vision abnormalities,
  • deafness, or
  • altered pain or touch sensations, as with peripheral neuropathy.

• Seizures or convulsions - This type of conversion disorder is associated pseudoseizures; these are difficult to describe, except to say that they look exactly like how most non-medical people think seizures should look.

• Mixed presentation - In some people, more than one type of symptom of conversion disorder may be present.

In some cases, the symptoms of conversion disorder can lead to physical problems - for example, in someone who has the paralysis or weakness form of conversion disorder, muscle atrophy can result from disuse.

If other problems are evident, or the symptoms are more generalised, the label somatisation disorder is sometimes used instead². If the problem is primarily pain or fatigue, these come under a different umbrella (pain and fatigue syndromes, respectively). If the problem is primarily that of fear of a disease that the patient doesn't have, then the diagnosis is one of hypochondriasis.

Physical causes need to be ruled out, and sometimes conversion disorder has been incorrectly diagnosed when a patient actually had a physical disease; some studies have found this to occur with as many as 25-50% of conversion disorder diagnoses. To make things even more difficult, conversion disorder can co-exist with another, separate physical disease as well. In such cases, the conversion disorder can lead to inappropriate over-treatment of the physical condition.

The symptoms of conversion disorder can be distinguished from purely physical symptoms by their inconsistent nature and the doctor's inability to correlate them to the effects of any known physical problem. Practically speaking, the symptoms just don't fit into the usual picture for any physical disorder. In other cases, normal results from diagnostic testing may point the physician in the direction of conversion disorder.

Conversion disorder frequently co-exists with depression and anxiety disorders, and the presence of these sometimes helps to make the diagnosis more likely.

It's important to mention that individuals who have the disorder are generally not aware of the psychological nature of their symptoms, and nor are they are not making up symptoms simply for the purpose of being sick - those who knowingly fake illnesses are known (and dreaded) in hospitals as malingerers.

The Case of 'Anna O'

This case, treated by Josef Breuer in Vienna and famously written up by Breuer and Sigmund Freud, is a typical case of conversion disorder - although the evidence for Breuer's cure has not been demonstrated by clinical trials.

A Famous Example of Conversion Disorder and its Treatment

Anna³ was troubled by (amongst other things) a squint, visual problems and paralysis of the right arm and neck. These symptoms didn't correspond to any known problem with the nervous system, and were somehow linked to her nursing her father through his final illness and his subsequent death.

Breuer hypnotised Anna, and in her trance she revealed some of the subconscious motivators behind her symptoms that she was unable to recall under normal circumstances. For instance, after recounting (under hypnosis) that she battled to hold back tears daily in order not to distress her dying father, her squint and visual disturbance resolved. Her paralysed arm was related to a dream in which a black snake attacked her father and she was unable to lift a finger to stop it. Similarly, once she recalled the circumstances which led to the paralysis, the symptoms disappeared.

Breuer and Freud used the case history to help formulate the first completely psychological explanation of hysteria, described below.

Causes of Conversion Disorder

As implied above, psychoanalytic theory states that conversion disorder is due to the alternative, physical expression of a forbidden desire that occurs under extreme stress. The desire is repressed and pushed down into the unconscious due to the stress it causes, where it is turned into a physical symptom as a coping strategy.

In other words, it is an unusual form of stress relief. There is usually a reduction in stress as the physical symptom develops, which is referred to as the 'primary gain'. Also, the advantages of the sick role (care, attention and generally being fussed over) are referred to as the secondary gain. The secondary gain aspect of this theory is similar to learning and sociological theories of conversion disorder.

Other schools of thought have developed alternative explanations for the disorder. New techniques of brain scanning, for instance, show that many people who are prone to conversion disorder have impaired signalling between the two cerebral hemispheres in their brain, and their dominant hemisphere is underactive relative to unaffected people. One study has shown that brain insults like tumours, strokes or epilepsy are up to ten times as common in people with conversion disorder compared to unaffected people. However, as with so much of this sort of research, it's difficult to tell whether this is the cause of the problem, one of the effects of the problem, or something which commonly happens alongside the problem.

How is it Treated?

In clinical trials, symptoms resolve quickly by themselves in 75% of affected individuals, particularly if the stressful trigger has passed and the patient was coping well beforehand.

Confronting patients about their symptoms and telling them to pull themselves together is in general found to be spectacularly counter-productive. On the other hand, encouraging or supporting the symptoms by special treatment should be avoided as well.

Psychoanalysis, cognitive behavioural therapy and brief psychotherapeutic interventions are often used, and hypnosis is sometimes still used as well. Medications such as anti-depressants and sedatives are sometimes used as well. Unfortunately, the limited research in this area means that it is difficult to know which, if any, of these options are truly effective.