[Conversion disorder: from DSM IV to DSM 5 or from a psychiatric to a neurological diagnosis]

According to one of the diagnostic criteria of the dsm iv for conversion disorder there has to be a temporal relationship between psychological factors and the onset, or the worsening, of the symptoms. This criterion has been omitted in the dsm-5. Another criterion, namely that the symptoms are not produced intentionally, has also been abandoned. A new recommendation is that therapists should look for neurological symptoms that support the diagnosis.

To investigate whether studies support the changes in the criteria.

We searched literature using PubMed.

When the symptoms first appear, trauma or stress in 37% of patients is of a physical rather than a psychological nature. Different forms of stress were found in equal proportions (20%) in patients with or without conversion disorder. There are no specific stressors, except possibly in patients with dysphonia. The percentages of childhood abuse vary widely, namely from 0 to 85%. The characteristic phenomenon of 'la belle indifference' occurs in only 3% of patients with conversion disorder versus only 2% of controls. Most of the 'positive' clinical tests for partial paralysis and sensory and gait disorders are highly specific. There are no reliable tests for distinguishing conversion disorder from simulation.

The changes of the criteria are supported by recent studies.