MELBOURNE – Sigmund Freud may have been right about repressed memories causing hysteria.
Scientists at King’s College London and the University of Melbourne have found, using brain scans, that psychological stress may be to blame for unexplained physical symptoms, including paralysis and seizures.
Patients showed differences in brain activity when they recalled traumatic memories compared with healthy volunteers in a study published in last month’s edition of JAMA Psychiatry. Besides supporting Freud’s theory and helping to explain one of the most common complaints seen by neurologists, the research may lead to new treatment approaches for patients whose symptoms were often written off by doctors in the past.
“This is the first paper that I’m aware of that really shows that previous traumatic events can definitely trigger this kind of motor response,” said John Speed, a professor of physical medicine and rehabilitation at the University of Utah in Salt Lake City, who wasn’t involved in the research. “It’s very exciting.”
The research is among the latest to demonstrate how brain-scanning devices are being used to help unravel neuropsychiatric symptoms.
The scientists used functional magnetic resonance imaging (fMRI) to trace changes in blood flow to particular areas of the brain while participants were probed about their past, yielding both anatomical and functional views of their brains.
“I hope in a decade or so that we will be able to use functional MRI as a diagnostic tool,” Speed said in a telephone interview.
Repressed memories were a tenet of Freud’s psychological theories about the nature of unconscious mental processes. The Austrian neurologist, who became known as the founding father of psychoanalysis, used the term “repression” to describe the way emotionally painful events could be blocked out of conscious awareness. This self-protective mechanism, he postulated, could bring on psychosomatic symptoms, labeled “hysteria” at the time, in a process now known as conversion.
Conversion disorder is one of the main reasons people visit a neurologist — accounting for 16 percent of neurology outpatients, according to a two-year study from Scotland the authors cited.
Cases typically manifest as weakness or paralysis down one side of the body reminiscent of a stroke. Symptoms can include nonepileptic seizures. Doctors have never found a neurological basis for the condition — the brains, nerves and muscles of patients all appeared to be normal — leading them to believe the symptoms are psychosomatic and raising suspicions that the patients are making up their illness, said Richard Kanaan, a professor of psychiatry at the University of Melbourne and a co-author of the study.
“It remains poorly understood, even by most physicians,” said Speed, who has treated more than 200 cases. “I’ve had countless patients tell me they weren’t believed, or were bluntly told they were faking it.”
The study, conducted by Kanaan and colleagues at King’s College London, involved 12 patients with conversion disorder and 13 healthy adults without the condition.
All participants were identified as having experienced stressful life events. The researchers used fMRI to pinpoint areas of brain activity when participants were asked to recall details about those experiences.
In the conversion patients, the reminiscing appeared to activate an area of the brain known as the left dorsolateral prefrontal cortex, whereas other memories — even upsetting ones — in both patient groups activated the hippocampus, a part of the brain important for the formation of memories.
The authors interpreted the different brain patterns to mean that conversion patients activated one part of their brain in order to still another, so that the emotional content of a stressful event could be suppressed.
“It is, I think, the first scientific exploration of something like a Freudian model that has been neglected for a long time,” Kanaan said in an interview in his office at Melbourne’s Austin Hospital, where he is head of psychiatry.
The research builds on earlier studies showing a correlation between the brain area used in processing memories and emotional reaction, and motor symptoms.
The latest finding needs to be repeated and validated in a study twice the size to be accepted with confidence, said Kanaan, who previously was a consultant neuropsychiatrist at London’s Maudsley Hospital, where he ran a clinic specializing in functional neurological disorders, and studied conversion disorder at the Institute of Psychiatry.
Kanaan and colleagues are now working with patients initially admitted to the hospital on suspicion of stroke, have recently experienced stress and who are found to not have a neurological disease.
“We do hope that when we get people who have had very recent experiences like that that we will be able to disentangle this much more clearly,” he said.
Freud’s approach in caring for conversion disorder patients was to uncover the suppressed trauma through psychotherapy and to help recall and reprocess those memories to alleviate symptoms.
“Giving people psychotherapy is in a way the orthodox solution, but it’s kind of fallen out of favor because there hasn’t been this kind of evidence to support it,” Kanaan said. “I certainly liked Freud from the first moment I read him,” he said. “This has given me more reason to think that he might have been right.”
Although Freud didn’t have tools to explore the mechanisms by which conversion disorder could occur, he “nailed the concept,” Speed said. “Conversion is simply a very uncommon and more severe physical manifestation of stress, in which there is a blockage of messages getting to or from the brain.”