Instead, the emphasis tends to be on the patients 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 using functional neuroimaging to study conversion. As researchers identify the mechanisms which underlie conversion symptoms, it is hoped they will enable the development of a neuropsychological model. A number of such studies have been performed, including some which suggest the blood-flow in patients brains may be abnormal while they are unwell. However, the studies have all been too small to be confident of the generalisability of their findings, so no neuropsychological model has been clearly established. An evolutionary psychology explanation for conversion disorder is that the symptoms may have been evolutionarily advantageous during warfare. A non-combatant with these symptoms signals non-verbally, possibly to someone speaking a different language, that she or he is not dangerous as a combatant and also may be carrying some form of dangerous infectious disease.
Conversion disorder (CD), or functional neurologic symptom disorder, is a diagnostic category used in some psychiatric classification systems. It is sometimes applied to patients who present with neurological symptoms, such as numbness, blindness, paralysis, or fits, which are not consistent with a well-established organic cause, which cause significant distress, and can be traced back to a psychological trigger. It is thought that these symptoms arise in response to stressful situations affecting a patients mental health or an ongoing mental health condition such as depression. Conversion disorder was retained in DSM-5, but given the subtitle functional neurological symptom disorder. The new criteria cover the same range of symptoms, but remove the requirements for a psychological stressor to be present and for feigning to be disproved. ICD-10 classifies conversion disorder as a dissociative disorder while DSM-IV classifies it as a somatoform disorder. Signs and symptoms
Conversion disorder begins with some stressor, trauma, or psychological distress. Usually the physical symptoms of the syndrome affect the senses or movement. Common symptoms include blindness, partial or total paralysis, inability to speak, deafness, numbness, difficulty swallowing, incontinence, balance problems, seizures, tremors, and difficulty walking. The symptom of feeling unable to breathe, but where the lips are not turning blue, can indicate conversion disorder or sleep paralysis. Sleep paralysis and narcolepsy can be ruled out with sleep tests. These symptoms are attributed to conversion disorder when a medical explanation for the conditions cannot be found. Symptoms of conversion disorder usually occur suddenly.