- Historical perspectives on FND
- Shifts in diagnostic criteria and terminology
- Neurobiological insights and current theories
- Clinical approaches and multidisciplinary management
- Emerging directions in FND research and education
The history of Functional Neurological Disorder (FND) dates back centuries, long before the term itself came into use. In antiquity, symptoms now associated with FND were often attributed to supernatural or spiritual causes. During the time of Hippocrates, conditions exhibiting seizure-like episodes without clear organic cause were frequently labelled under the concept of “hysteria”, which was thought to originate in disturbances of the uterus—thus reflecting the gendered perceptions that dominated early medical understanding.
It was not until the 17th and 18th centuries that the framework of thinking around these disorders began to shift towards a more scientific approach. Physicians such as Thomas Sydenham started to document cases resembling FND with clinical detail, although the underlying mechanisms remained elusive. In the 19th century, Jean-Martin Charcot, a prominent neurologist at the Salpêtrière Hospital in Paris, played a pivotal role in placing such disorders within the field of neurology. Charcot distinguished between organic neurological disease and what he termed “hysteria”, asserting that the latter also required rigorous neurological investigation. However, his students, including Sigmund Freud, began to emphasise psychological interpretations, leading to the development of psychoanalytic theories that reframed these disorders as manifestations of repressed trauma.
Throughout the 20th century, psychoanalytic models dominated the discourse surrounding FND. However, many neurologists remained sceptical, struggling with the absence of identifiable structural abnormalities and the lack of consistent physiological markers. Patients presenting with functional symptoms were often misunderstood and marginalised within the medical system, partly due to the dichotomy between psychiatry and neurology. This clinical gap highlighted the limitations in the prevailing models of medical understanding and the urgent need for a more integrated framework.
It was not until the late 20th and early 21st centuries that a gradual paradigm shift began to emerge. Renewed interest in FND coincided with more sophisticated diagnostic technologies and a more nuanced appreciation of how brain function could become disordered without structural damage. This changing perspective laid the foundation for a more compassionate, evidence-based approach to FND, steering away from outdated notions rooted in historical bias and insufficient knowledge.
Shifts in diagnostic criteria and terminology
The evolution of diagnostic criteria and terminology in relation to Functional Neurological Disorder (FND) reflects broader changes in medical understanding and clinical practice. Historically framed under terms like “hysteria” or “conversion disorder”, the language surrounding FND was heavily influenced by psychoanalytic theory, implying a psychogenic origin without supporting neurological evidence. These labels often carried significant stigma and contributed to patient marginalisation, as they implied psychological weakness or emotional instability without acknowledging complex neurobiological contributors.
Over time, the inadequacy of psychoanalytically derived terms became more evident, particularly as clinicians in neurology grappled with the gap between patients’ disabling symptoms and a lack of corresponding structural abnormalities. The term “conversion disorder” remained part of diagnostic manuals such as the DSM and ICD for much of the 20th century, yet many neurologists found it insufficient to describe the breadth of presentations and inconsistent with growing insights from neuroimaging and clinical observation.
In response to these limitations, the term “Functional Neurological Disorder” has gained prominence, marking a pivotal shift towards a more descriptive, less stigmatising nomenclature. The adoption of FND acknowledges that while symptoms are real and involve dysfunction in the nervous system, they do not arise from structural damage but rather from altered patterns of brain function. This change signifies a move away from speculative psychological explanations toward a model grounded in clinical neurology and empirical data.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), formally incorporated this shift by recognising FND under the heading of “Functional Neurological Symptom Disorder.” Crucially, diagnosis in DSM-5 no longer requires evidence of a preceding psychological stressor, focusing instead on positive clinical signs and observed incongruities in presentation. This has empowered clinicians to base the diagnosis on observable phenomena, rather than exclusion or assumptions about underlying psychological issues.
Furthermore, awareness is growing that symptom expression in FND can overlap with other neurological and psychiatric conditions, necessitating a nuanced, multidisciplinary approach. The refinement of terminology and diagnostic criteria has influenced research trajectories, clinical training, and patient care practices, contributing to the legitimisation of FND within mainstream neurology. By incorporating up-to-date neuroscientific knowledge and shifting away from outdated labels, medical understanding of FND is steadily aligning with advances in patient-centred care and evidence-based practice.
Neurobiological insights and current theories
Recent advancements in brain imaging and neurophysiology have significantly deepened our medical understanding of Functional Neurological Disorder (FND), shifting the focus from purely psychological interpretations to neurobiological mechanisms. Functional MRI (fMRI), electroencephalography (EEG), and other neuroimaging tools have demonstrated that brain function in FND is measurably different, even in the absence of structural abnormalities. These findings indicate that FND symptoms are not imagined or feigned, but stem from alterations in brain networks governing attention, movement, sensation, and emotion.
Studies have revealed that in individuals with FND, brain areas involved in motor control, such as the supplementary motor area and prefrontal cortex, show altered activity during symptom manifestation. This suggests dysfunction in the circuits that modulate initiation and control of movement, which may explain symptoms like limb weakness, tremors, or gait abnormalities. Similarly, research into functional seizures has found evidence of changes in connectivity involving the amygdala, insula, and anterior cingulate cortex—regions associated with emotion processing and self-awareness—highlighting a neurobiological basis for episodes that were historically labelled as “psychogenic”.
A growing body of work supports the concept that FND arises from disconnections or maladaptive functioning within neural networks, rather than damage to a single brain region. The Bayesian model of perception and movement has been applied to FND, positing that symptoms arise from strong prior expectations or beliefs that override sensory feedback. This model helps explain why patients experience very real symptoms, despite “normal” neurological tests, as the brain’s predictive systems misinterpret or suppress incoming information, resulting in altered motor or sensory experiences.
Additionally, attention and self-monitoring play a significant role in symptom perpetuation. Hyper-awareness of bodily sensations, coupled with heightened anxiety or stress, may exacerbate symptoms. Investigations using attention-based paradigms show that patients with FND may unconsciously redirect their focus in a manner that disrupts normal motor and sensory processing. This supports the idea that FND involves an involuntary breakdown in the brain’s automatic systems, challenging the outdated belief that patients have conscious control over their symptoms.
Importantly, the growing understanding of these neurobiological mechanisms is helping bridge the historical divide between psychiatry and neurology. It positions FND as a legitimate neuropsychiatric condition, rooted in brain dysfunction rather than psychological fabrication. The integration of neuroscience into clinical models has validated patients’ experiences and fostered more compassionate, effective care pathways. As research continues to uncover the intricate neural underpinnings of FND, it is becoming increasingly clear that the disorder exists at the intersection of brain, mind, and behaviour, necessitating interdisciplinary collaboration to unravel its complexities.
Clinical approaches and multidisciplinary management
Effective clinical management of Functional Neurological Disorder (FND) requires a nuanced, multidisciplinary approach that integrates neurology, psychiatry, physiotherapy, occupational therapy, psychology, and social support systems. This collaborative model seeks to address the complex interplay of motor, sensory, cognitive, and emotional symptoms often observed in FND, recognising that symptom severity and presentation can vary greatly among individuals. Historically misunderstood and marginalised within traditional medical frameworks, FND now benefits from a more integrated and person-centred model of care that reflects recent advancements in medical understanding and acknowledges the legitimacy of the disorder within the field of neurology.
Diagnosis and communication are crucial in the initial phase of management. Clinicians are encouraged to deliver the diagnosis of FND with clarity and empathy, providing validation of the patient’s symptoms while avoiding outdated language that implies judgement or trivialisation. The use of positive clinical signs—such as Hoover’s sign or tremor entrainment test—serves as an evidence-based foundation for diagnosis, reducing reliance on exclusion and supporting more timely intervention strategies. Educating patients about their condition using diagrams, analogies, and accessible explanations can foster therapeutic engagement and reduce anxiety, resentment, or mistrust often shaped by precarious diagnostic histories.
Physiotherapy has emerged as a cornerstone of FND treatment, especially for patients presenting with motor symptoms. Functional physiotherapy prioritises goal-oriented rehabilitation over traditional strength-based regimens, focusing on retraining movement patterns and improving automatic motor control. Clinicians work collaboratively with patients to identify and overcome maladaptive movement habits, often using distraction and task-specific training to bypass dysfunctional motor circuits. This approach is underpinned by evidence demonstrating that motor symptoms in FND result from altered functional brain activity, rather than musculoskeletal or neurological damage.
For patients experiencing functional seizures or dissociative episodes, psychological therapies—particularly cognitive behavioural therapy (CBT)—have demonstrated utility in reducing symptom frequency and improving quality of life. CBT in this context typically addresses underlying stressors, maladaptive thought patterns, and avoidance behaviours while promoting effective coping strategies. Acceptance and Commitment Therapy (ACT) and mindfulness-based interventions are also being increasingly adopted to help patients manage chronic symptoms without becoming overwhelmed by distress. Importantly, psychological treatment should be framed not as an implication of feigned illness, but as a genuine tool to engage with brain-behaviour dynamics contributing to symptom maintenance.
Occupational therapists play a vital role by assisting patients in resuming routine activities, reintegrating into employment or education, and managing fatigue or cognitive fog. Tailored strategies that support pacing, planning, and structured routines can restore a sense of autonomy and competence, which are often eroded in the context of chronic functional symptoms. Nurses and social workers further augment the care team by coordinating services, ensuring access to benefits and accommodations, and offering psychosocial support to both patients and families.
The success of multidisciplinary management lies in consistent messaging and shared clinical understanding across professionals. Regular team meetings, care coordination pathways, and collaborative goal setting enhance continuity and reduce the risk of fragmented or conflicting care. Furthermore, patient inclusion in care planning empowers individuals to take an active role in their recovery journey, an important psychological shift given the feelings of helplessness that typically accompany the FND experience.
Challenges persist, such as limited availability of specialist services, inconsistent training among clinicians, and residual stigma that can still influence treatment pathways. Nevertheless, the momentum toward a coordinated, biopsychosocial approach reflects a significant departure from the fragmented responses of the past. Rooted in contemporary neurology and informed by a growing base of evidence, this model holds promise for improving clinical outcomes and rebuilding trust between patients and providers. As the history of FND is being rewritten in the light of better medical understanding, the value of multidisciplinary management stands out as a beacon of progress in this evolving field.
Emerging directions in FND research and education
In recent years, there has been an accelerating interest in both research and education related to FND, reflecting a broader shift in medical understanding and a growing recognition within neurology of FND as a legitimate and treatable condition. A key driver of this change has been the collective push towards collaborative, cross-disciplinary research frameworks that bring together neurologists, psychologists, physiotherapists, and patient advocates. These concerted efforts aim not only to deepen scientific understanding but also to develop practical, evidence-based interventions that can be applied across clinical settings.
New research directions are increasingly leveraging advances in computational neuroscience, brain network modelling, and machine learning to uncover biomarkers that might assist in diagnosing FND more effectively and objectively. For example, research teams are investigating patterns of functional connectivity using resting-state and task-based neuroimaging, exploring whether stable neural signatures of FND can be identified across large patient cohorts. Similarly, wearable technology and digital health tools are being explored to monitor symptoms remotely, offering real-time data that could inform personalised treatment plans and provide early indicators of functional decline or recovery.
Education efforts have also expanded considerably, with several international organisations and academic neurology departments prioritising training on FND for medical students, neurology residents, and allied health professionals. Training programmes now commonly include simulation-based learning, interactive modules focused on communication techniques, and joint sessions with mental health professionals to underline the biopsychosocial nature of the disorder. These initiatives are essential, as knowledge gaps and misconceptions among clinicians continue to affect the diagnostic journey, often prolonging patient distress and undermining trust in the healthcare system.
Patient and public involvement (PPI) is another area transforming the research and educational landscape of FND. Researchers are increasingly recognising the value of including individuals with lived experience of FND as co-designers of studies, curriculum advisors, and peer educators. This collaborative model not only ensures that research addresses meaningful outcomes but also contributes to destigmatising FND both within and beyond medical settings. Patients’ narratives are being integrated into training materials and public outreach efforts to challenge outdated stereotypes and promote a more empathetic clinical culture.
Funding structures are adapting to support this evolving research ethos. Institutions such as the National Institute for Health Research (NIHR) and the Medical Research Council (MRC) in the UK have started to include FND in funding calls under neurological and mental health categories. This inclusion not only validates FND’s position within mainstream clinical science but also facilitates studies that examine long-term outcomes, healthcare utilisation, and the cost-effectiveness of multidisciplinary care—a crucial step in advocating for systematic service provision.
Finally, research dissemination is shifting from traditional academic channels towards more accessible platforms, such as open-access journals, patient-led conferences, and social media campaigns. These outlets allow for faster translation of research findings into clinical practice and empower patients by keeping them informed and engaged in their care. Podcasts, webinars, and video series are being developed to engage healthcare providers and members of the public, broadening awareness and smoothing the path for early recognition and intervention.
As the field continues to evolve, the intersection of research and education plays a pivotal role in shaping the future of FND care. Grounded in a comprehensive appreciation of the neurological and psychosocial dimensions of the disorder, emerging efforts reflect a subtle but crucial redefinition of what it means to approach FND with scientific rigour and clinical humanity. This marks a significant shift in the ongoing history of medical understanding, where FND is no longer a marginal curiosity but a dynamic and legitimate sphere of modern neurology.
