Special Journal Issue on Functional Neurological Disorder Brings Attention to a Neglected Field: Investigator Q&A

The latest issue of The Journal of Neuropsychiatry & Clinical Neurosciences (JNCN) focuses on Functional Neurological Disorder (FND), a neuropsychiatric condition with significant physical and mental health features. Psychiatrists commonly refer to this condition as Conversion Disorder, whereas neurologists may be more familiar with terms such as functional movement disorders and dissociative seizures, among other subtypes of FND.

Largely understudied until recently, FND presents a critical challenge to practitioners in neurology and psychiatry. Furthermore, the complex issues faced by patients require evidence-based approaches to both treatment and the medical community’s fundamental understanding of the disorder. In light of these challenges, the 5 guest co-editors of the special issue — David L Perez, MD, MMSc, Selma Aybek, MD, Timothy R Nicholson, MD, PhD, Kasia Kozlowska, MBBS, PhD, W Curt LaFrance, Jr, MD, MPH — put together a series of articles touching on risk factors, treatment approaches, and outcome measures, among other key topics. Psychiatry Advisor contacted Dr Perez and Dr Nicholson to discuss the special issue of JNCN and the state of the field.

Psychiatry Advisor: In your view, what is the significance of this special issue, the first published on FND in nearly 2 decades?

David Perez, MD, MMSc: This special issue on FND is a landmark event for the field. FND is among the most common conditions encountered by neurologists and neuropsychiatrists, yet because this diagnosis falls at the borderland between neurology and psychiatry, it has not had the clinical, academic, and research attention it deserves.

Over the last few decades, there have been significant breakthroughs in evidence-based diagnostic and treatment approaches, as well as the development of an improved understanding of disease mechanisms, resulting in renewed interest in FND across the clinical neurosciences. This progress is exemplified by the broad range of articles within our special issue on FND.

Psychiatry Advisor: How has our understanding of FND changed since the formative era of modern neuropsychiatry in the early 20th century?

Dr Perez: It is important to highlight that FND, previously termed hysteria and synonymous with Conversion Disorder, was of great interest to early pioneers in psychiatry and neurology, including Charcot, Freud, Janet, Babinski, and others. One of the major hopes of this special issue is that this effort will energize clinicians and researchers across the clinical neurosciences to care for and develop cutting edge research in this underserved population.

Foundational to our modern framing is the notion that FND is a neuropsychiatric disorder at the intersection of the mind and the brain.  According to our perspective, this condition is brain-based and neural circuits do not artificially divide into “neurological” circuits and “psychiatric” circuits. An integrated, interdisciplinary approach that embraces neurologic, psychiatric, psychological, and rehabilitation perspectives is the present and future of FND clinical and research efforts. 

Additionally, it is now recognized that there are a number of predisposing vulnerabilities or risk factors for the development of FND, and adverse life events may have etiological relevance for some but not all patients. This point is nicely exemplified by Professor Jon Stone and colleagues in their study of individuals with functional limb weakness, which notes that only about a third of patients in their sample reported childhood abuse and/or neglect.1

Psychiatry Advisor: In a recent article, an international panel of experts was organized to discuss the complexities of developing outcome measures for FND.2 Why is this an important issue in the field?

Timothy Nicholson, MD, PhD: With the long overdue growth of both clinical service provision for FND and research into its treatments comes a need to optimize outcome measurements to monitor changes in symptoms. Designing and selecting outcome measures is a complex task for any disorder, but there are particular features of FND that make this even more complex. These features, such as the wide variety of symptoms in FND and the potential for subjective rather than objective measures to be of more relevance than in other disorders, are discussed in this perspective article from a panel of 45 experts from 13 countries that aims to drive forward consensus and development of outcome measures in FND.

Psychiatry Advisor: What does FND tell us about the divide between mental and physical health?

Dr Nicholson: FND is the quintessential disorder through which to understand and conceptualize that mental and physical health are inherently intertwined, and any “divide” is an illusion that hinders both research and clinical care for mental health disorders, neurological disorders, and those in between. Patients with FND present with neurological symptoms that can resemble almost all other neurological disorders, but remain discernable by distinct clinical examination features (so-called “positive signs”).

The condition also has complex interactions with psychological processes (such as dissociation) and psychological disorders (such as PTSD and panic attacks) that have led to the traditional dominance of psychological models of the disorder. However, such models must of course be rooted in neurological (or brain-based) dysfunction, albeit at a complex multi-network level. There are exciting new theories, such as Bayesian computational models for motor and sensory dysfunction in FND that point the way forward for neuroscientific approaches. These models integrate mental and physical functions, ignoring the mirage of any false divide between them.

Psychiatry Advisor: Your editorial mentions the feasibility of implementing physical therapy for motor FND. Can you highlight other specialties outside of neurology and psychiatry that would benefit patients with FND?

Dr Perez: In addition to neurologists and psychiatrists, optimal care often involves physical therapists, occupational therapists, speech and language pathologists, psychologists, and/or social workers, among other disciplines. This interdisciplinary approach to FND is highlighted by the tree diagram that appears on the cover image for our special issue.

Psychiatry Advisor: The special issue includes an article detailing the establishment of specialized FND clinics in the United Kingdom, Switzerland and Canada. What does quality care for patients with FND currently look like?

Dr Perez: While FND care will certainly require robust engagement with general neurologists and psychiatrists, it is also encouraging that both here in the United States and internationally, such as in the United Kingdom, Switzerland, and Canada, subspecialty FND clinical programs have been developed. The article by Dr. Selma Aybek, one of the guest co-editors for this special issue, highlights the potential role of outpatient subspecialty FND clinics.3 Their roles include providing diagnostic clarification in challenging cases, as well as helping patients connect to evidence-based treatments, such as motor retraining and psychological treatments, particularly cognitive behavioral therapy.

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Psychiatry Advisor: Patients with FND present with a wide variety of symptoms and comorbidities. In the context of such heterogeneity, how should clinicians approach treatment strategies?

Dr Perez: From a treatment perspective, the special issue adds to an emerging new outpatient model of care emphasizing roles for diagnostic clarification,3 treatment using cognitive behavioral therapy,4 and motor retraining as part of FND-specific physical therapy.5

Psychiatry Advisor: As you noted in your editorial, FND receives little attention, but when it does, it frequently arises as a “medical mystery” in stories of mass psychopathology, most recently in the case of the US embassy in Cuba. How can physicians and advocates bring attention to the far more common experiences of the patients you see on a regular basis?

Dr Perez: Indeed, FND is often “hiding in plain sight,” as illustrated in the article6 by Dr Popkirov and colleagues, which provides evidence that some popular news stories on medical mysteries can be reliably identified as cases of FND on the basis of positive signs of functional movement disorders or dissociative seizures. This phenomenon illustrates the critical importance of training clinicians across disciplines in the diagnosis of FND, including the delivery of the diagnosis in a way that patients can understand and accept, as well as increased awareness and understanding of the disorder among the general public. We hope that public awareness will improve and medical research funding will expand for this underserved population through academic efforts such as this special issue, educational initiatives on FND in medical school and residency training settings, and patient advocacy through organizations such as FND Hope and FND Action. The newly formed FND Society will have its inaugural conference this summer in Boston, which will include a strong training component for all relevant clinicians and scientists who want to learn more about this important, yet poorly understood, disorder.


  1. Stone J, Warlow C, Deary I, Sharpe M. Predisposing risk factors for functional limb weakness: a case-control study [published online August 30, 2019]. J Neuropsychiatry Clin Neurosci. doi:10.1176/appi.neuropsych.19050109
  2. Nicholson TR, Carson A, Edwards MJ, et al. Outcome measures for functional neurological disorder: a review of the theoretical complexities [published online December 23, 2019]. J Neuropsychiatry Clin Neurosci.doi:10.1176/appi.neuropsych.19060128
  3. Aybek S, Lidstone SC, Nielsen G, et al. What is the role of a specialist assessment clinic for FND? Lessons from three national referral centers [published online December 23, 2019]. J Neuropsychiatry Clin Neurosci. doi:10.1176/appi.neuropsych.19040083
  4. O’Connell N, Watson G, Grey C, Pastena R, McKeown K, David AS. Outpatient CBT for motor functional neurological disorder and other neuropsychiatric conditions: a retrospective case comparison [published online December 23, 2019]. J Neuropsychiatry Clin Neurosci.doi:10.1176/appi.neuropsych.19030067
  5. Maggio JB, Ospina JP, Callahan J, Hunt AL, Stephen CD, Perez DL. Outpatient physical therapy for functional neurological disorder: a preliminary feasibility and naturalistic outcome study in a U.S. cohort [published online December 23, 2019]. J Neuropsychiatry Clin Neurosci.doi:10.1176/appi.neuropsych.19030068
  6. Popkirov S, Nicholson TR, Bloem BR, et al. Hiding in plain sight: functional neurological disorders in the news [published online December 23, 2019]. J Neuropsychiatry Clin Neurosci. doi:10.1176/appi.neuropsych.19010025