Conversion disorder

Conversion disorder (CD) is a formerly used term, describing a psychiatric disorder characterized by abnormal sensory experiences and movement problems during periods of high psychological stress. Individuals diagnosed with CD presented with highly distressing neurological symptoms such as numbness, blindness, paralysis, or convulsions, none of which were consistent with a well-established organic cause and could be traced back to a psychological trigger.^[1] CD was present in ICD-10 and DSM-IV, but been removed from the newer versions of both, being superseded in those by functional neurologic disorder (FND), a similar diagnosis that notably removed the requirement for a psychological stressor to be present, as well as Somatic symptom disorder and Bodily distress disorder.

It was thought that these symptoms arise in response to stressful situations affecting a patient's mental health. Individuals diagnosed with conversion disorder have a greater chance of experiencing certain psychiatric disorders including anxiety disorders, mood disorders, and personality disorders compared to those diagnosed with neurological disorders.^[2]

Conversion disorder was partly retained in the DSM-5-TR and ICD-11, but was renamed to functional neurological symptom disorder (FNsD) and dissociative neurological symptom disorder (DNSD), respectively. FNsD covers a similar range of symptoms found in conversion disorder, but does not include the requirements for a psychological stressor to be present. The new criteria no longer require feigning to be disproven before diagnosing FNsD. A fifth criterion describing a limitation in sexual functioning that was included in the DSM-IV was removed in the DSM-5 as well.^[3] The ICD-11 classifies DNSD as a dissociative disorder with unspecified neurological symptoms.^[4][5]