What is conversion disorder, and how common is it?
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, text revision, conversion disorder (also known as functional neurological symptom disorder) is characterized as a somatic symptom and related disorder.1 The prominent feature shared among disorders in this category is the presence of somatic symptoms that are associated with distress and impairment.
In conversion disorder, the focus is on symptoms that are neurologic in nature but are not due to underlying neurologic disease and are incongruent with typical patterns of presentation for any neurologic condition. Patients with conversion disorder may present with motor symptoms (eg, weakness, paralysis, tremor, dystonia), altered sensory or cognitive function, seizure-like symptoms, alterations in speech, or changes in swallowing.1,2
For a diagnosis of conversion disorder,the following criteria must be met1:
The patient has 1 or more symptoms of altered voluntary motor or sensory function.
Symptom presentation is incongruent with recognized neurologic or medical disease or conditions.
Symptoms are not better explained by another medical or mental health condition.
There is significant distress or impairment in functioning due to symptoms or the deficit.
The etiology of conversion disorder has not been firmly established. While the literature suggests that psychological stressors play a role,3,4 an effort also has been made to better understand the underlying neural and biological basis. Specifically, studies have utilized brain imaging to explore brain pathways and mechanisms that could account for symptom presentation.5,6
Prevalence rates for conversion disorder vary depending on the population studied. While it is estimated that 5% of patients in a general hospital setting meet full criteria for conversion disorder,7 higher rates may exist in specialty settings; 1 study found that 30% of patients in a neurology specialty clinic exhibited symptoms that were medically unexplained.8