A new study suggests the Freudian theory that stress or trauma can trigger hysteria or a conversion reaction is at least partly accurate. However, researchers discovered approximately 10 percent of cases could not be linked to psychological distress.
Freud believed psychological stress can cause the neurological symptoms such as paralysis or seizures often associated with what is now known as Conversion Disorder (CD) or, increasingly, as Functional Neurological Disorder (FND). The study, published in Psychological Medicine, found supportive evidence that stressors around the time of onset of symptoms might be relevant for some patients.
This research is the first to robustly assess this key theory.
Currently, CD is a complex and much misunderstood disorder at the interface of neurology and psychiatry. In the disorder, neurological symptoms occur in the absence of identifiable neurological disease. Historically, the symptoms have been assumed to be psychological in origin, although this is being increasingly challenged.
Although CD is one of the most frequent causes of neurological symptoms, research has focused on other common and disabling disorders, such as multiple sclerosis. As a result, the causes of CD remains largely unknown and there are few effective treatments.
This study of 43 CD patients with physical weakness, 28 depression patients, and 28 healthy controls used the Life Events and Difficulties Schedule (LEDS), the most robust method for detecting, categorizing and rating severity of stressors around the time of symptom onset.
Critically, this method relies on a trained researcher gathering comprehensive detail of the person’s life and relationships before systematically enquiring about all conceivable forms of stress. Therefore the true severity of superficially innocuous events, such as a family reunion, can be revealed by the complexity of family relationships and past events.
The researchers found that patients with CD had experienced significantly more severe life events than controls, and this relative difference increased the closer they looked to symptom onset.
Specifically, in the month before symptom onset at least one severe event was identified in 56 percent of CD patients, 21 percent of depression patients, and 18 percent of healthy controls. However, in nine percent of CD patients no stressors were identified in the year before symptom onset.
Dr. Tim Nicholson, a neuropsychiatrist from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London, said, “The fact that we found more stressors in CD patients compared to controls supports their relevance to the onset of the disorder, particularly as the frequency of events dramatically increased the closer we looked to symptom onset.”
“However, it is particularly important that despite using such a thorough method, and in a population who had been referred to a psychiatrist, a significant proportion of the CD patients — nine percent — did not have an identifiable stressor.”
This finding challenges Freud’s theory that such traumas are the sole cause of this disorder, Nicholson said. The discovery that for some, symptoms may result from something other than stress or trauma matches new findings that patients become distressed when experts assume that there must be an underlying causative stressor.
“When one is not found it has been assumed by many clinicians that it is being ‘repressed’ from consciousness or, even more damagingly, being actively denied by the patient,” he said.
Bridget Mildon, founder and president of FND Hope (the leading patient organization for CD), said, “The lack of understanding about the causes of this highly debilitating disorder makes research like this vital.
While stress can trigger many illnesses this is one disorder where those without identifiable stressors potentially hold the key to many questions. More research is critical if we are to unravel the mystery behind functional neurological symptoms.”
The potential mechanism by which stress can cause such symptoms has been investigated in previous work by Nicholson and colleagues in functional brain imaging studies that look at brain activations in patients using MRI scans.
This research found evidence that CD patients activate parts of their brains differently, particularly areas involved in emotion processing, when thinking back to stressful events that were considered relevant to the onset of their symptoms compared to equally severe events.
Said Nicholson, “So, was Freud wrong about hysteria? The answer is both yes and no. The results definitively show that Freud was wrong that stress will always be found. However, our study indicates he might have been right in that stressors or trauma are likely to be involved in causing CD, at least in some patients.
“The challenge is now to work out what the cause, or causes, are in a given individual and then develop tailored treatments that can hopefully be more effective than those we currently offer for this common and misunderstood disorder.”
Source: Kings College London