A Brief History of Functional Neurological Disorder

This page is a selective timeline of major changes in how clinicians have recognized, diagnosed, explained and treated functional neurological symptoms. It is not a complete history of every theory or researcher.

[!NOTE] Historical terms such as hysteria, psychogenic, conversion disorder and non-organic are included because they were used in the literature. Their appearance here does not mean that this project recommends those terms today.

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Timeline at a glance

Period	What changed	Why it mattered	Representative source
Late 1800s	Jean-Martin Charcot and other neurologists described recurring neurological-looking syndromes then grouped under “hysteria.”	This period brought sustained neurological interest. Historical categories covered a broader range of presentations than modern FND.	Stone, 2016 historical review. [13]
1890s	Psychological models of hysteria and “conversion” became increasingly influential, especially through the work of Breuer and Freud.	These models strongly shaped 20th-century terminology and the assumption that neurological symptoms should be explained through psychological conflict. Modern FND diagnosis does not require such a cause.	Stone, 2016 historical review. [13]
1908	Charles Franklin Hoover described the leg sign now called Hoover’s sign, showing that apparently weak voluntary hip movement could differ from movement recruited automatically during another task.	This is an early example of a positive bedside sign based on how movement changes under different conditions.	Hoover’s original 1908 report. See the project’s Hoover’s Sign page and later prospective validation by McWhirter et al., 2011. [2][14]
1914–1945	Large numbers of soldiers developed paralysis, tremor, gait problems, seizures, sensory symptoms and other functional presentations during and after war.	War-related presentations influenced competing accounts of symptoms and the separation between neurology and psychiatry. Wartime labels cannot be mapped directly onto present-day FND.	Stone, 2016 historical review. [13]
1965	Eliot Slater’s influential paper “Diagnosis of ‘Hysteria’” argued that many patients given the diagnosis later proved to have neurological or medical disease.	The paper helped drive justified concern about careless diagnosis by exclusion. Later follow-up studies found lower error rates; differences in study quality and case definitions matter when comparing eras.	Slater, 1965; later reassessment in Stone et al., 2005. [15][16]
1980s–1990s	“Conversion disorder” became formalized in psychiatric diagnostic systems, with psychological formulation remaining central.	This period reinforced a psychiatric home for the diagnosis, but also contributed to a split between neurology and psychiatry that modern multidisciplinary FND care is trying to repair.	The later problems with these criteria are reviewed by Stone et al., 2011. [17]
2000s	Research increasingly re-examined misdiagnosis, clinical phenomenology and positive neurological signs rather than treating FND only as a diagnosis of exclusion.	This helped move the field toward making the diagnosis from recognizable clinical features while still assessing appropriate alternatives and coexisting disease.	Stone et al., 2005. [16]
2012	Edwards and colleagues proposed a Bayesian/predictive account linking expectations, attention, agency and motor control.	It helped connect FND to experimentally testable models of brain function rather than requiring one hidden psychological event to explain symptoms. It remains a model, not a complete proven mechanism for every person or symptom.	Edwards et al., 2012. [18]
2013	DSM-5 changed the diagnostic framework for functional neurological symptom disorder. A psychological stressor was no longer required, and clinical evidence of incompatibility with recognized neurological disease became central.	This formalized an important change: FND could be diagnosed using positive clinical evidence without first proving a psychological cause.	Discussed in Espay et al., 2018. [1]
2015	An international physiotherapy consensus described FND-specific rehabilitation principles for functional motor disorders.	Rehabilitation increasingly focused on retraining movement, reducing unhelpful self-focused control and building function alongside individualized assessment of strength, safety and other rehabilitation needs.	Nielsen et al., 2015. [5]
2018	A major JAMA Neurology review summarized FND as a disorder that can be diagnosed positively and treated through multidisciplinary, symptom-appropriate care.	It helped consolidate the modern clinical framework across neurologic diagnosis, rehabilitation and psychological care.	Espay et al., 2018. [1]
2020	Occupational-therapy consensus recommendations and the large CODES functional-seizure psychotherapy trial broadened the evidence base beyond diagnosis alone.	OT recommendations addressed everyday participation. CODES found no significant between-group difference in its primary seizure-frequency outcome at 12 months, alongside improvements on several secondary measures.	Nicholson et al., 2020; Goldstein et al., 2020. [6][19]
2021	Consensus recommendations were published for functional communication, swallowing, cough and related disorders.	The paper consolidated existing speech-language expertise into FND-specific recommendations; it did not mark the beginning of care for these symptoms.	Baker et al., 2021. [7]
2022	Hallett and colleagues reviewed emerging FND subtypes and shared mechanisms across movement, seizures, cognition and related presentations.	The field increasingly studied FND as interacting brain-network processes rather than one lesion or one universal psychological mechanism.	Hallett et al., 2022. [4]
2024	The multicentre phase-3 Physio4FMD trial tested specialist physiotherapy for functional motor disorder in routine clinical services. Clinical neurophysiology guidance also consolidated laboratory-supported approaches for some functional motor disorders.	Specialist physiotherapy was not superior on the primary 12-month physical-function outcome; several secondary measures favoured it. Neurophysiology guidance described supporting tests for selected motor presentations.	Nielsen et al., 2024; Edwards et al., 2024. [20][21]
2025	Multidisciplinary treatment recommendations emphasized coordinated, individualized care rather than one required treatment pathway. Research also increasingly examined patient-defined outcomes, prognosis and access to care.	The question shifted from “Which single treatment fixes FND?” toward “Which needs does this person have, who is responsible for each, and which outcomes matter to them?”	Lehn et al., 2025; Rutten et al., 2025. [8][9]
Late 2025–2026	The AAN functional-seizures guideline appeared online in December 2025 and in a January 2026 issue. Studies examined sensory signs, tremor electrophysiology and diagnostic communication.	These are different kinds of evidence: guidance, a case-control study and research syntheses. Each has symptom-specific limits; none establishes a universal FND test or treatment.	Tolchin et al., 2026; Nielsen et al., 2026; Rujirussawarawong et al., 2026; Silva & Silva, 2026. [3][10][11][12]

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What changed most?

From exclusion toward positive diagnosis

Older practice often treated functional symptoms as what remained after tests failed to find another explanation. Modern diagnosis instead looks for positive clinical features that support a functional diagnosis while still investigating other conditions when appropriate. Hoover’s sign, distractibility, entrainment and phenotype-specific seizure assessment are examples of this broader change. [1][2][3]

From one psychological explanation toward multiple testable mechanisms

Psychological factors can matter greatly for some people, but current FND models also investigate attention, prediction, agency, learned motor patterns, sensory processing, autonomic state, prior experience and interactions between brain networks. No one mechanism has been shown to explain every FND symptom in every person. [1][4][18]

From one profession toward coordinated care

Neurology remains important for diagnosis and reassessment, but rehabilitation, occupational therapy, speech-language therapy, psychology, psychiatry, primary care, nursing and other specialties may each address different needs. Modern guidance increasingly describes FND care as need-based and multidisciplinary, not as a hand-off from one specialty to another. [5][6][7][8]

From symptom counts toward meaningful outcomes

Recent studies increasingly measure daily function, participation, quality of life, communication, treatment burden and patient priorities rather than relying on symptom frequency alone. That does not make symptom reduction unimportant; it broadens what improvement can mean. [9][19][20]

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Reading the recent findings carefully

CODES (2020): 368 adults were assigned to seizure-specific CBT plus standardized medical care or standardized medical care alone. At 12 months, the primary monthly seizure-frequency comparison was not statistically significant (incidence rate ratio 0.78; 95% confidence interval 0.56–1.09). Several secondary measures, including psychosocial function and seizure bothersomeness, favoured CBT. These were multiple comparisons without statistical correction, so the results need balanced interpretation. This was evidence about a treatment package in selected adults, not proof of what caused their seizures. [19]

Physio4FMD (2024): 355 adults were randomized to specialist physiotherapy or community neurological physiotherapy. The main analysis included 241 after pandemic-related exclusions and other missing follow-up. The primary physical-function score at 12 months did not differ significantly (adjusted difference 3.5 points; 95% confidence interval −2.3 to 9.3). Some secondary outcomes favoured specialist care. This comparison does not establish that physiotherapy is ineffective; both groups received an active care pathway. [20]

Sensory signs (2026): a study compared 102 people with motor FND with 75 people with recent stroke. Midline splitting of light touch did not reliably separate the groups. This is a useful reminder that familiar signs need validation. Results in motor FND cannot automatically be extended to every isolated sensory presentation. [12]

Other 2026 developments: the tremor meta-analysis concerns the accuracy of electrophysiological tests for tremor, not a general FND biomarker. The AAN guideline addresses functional seizures, including coexisting epilepsy and continuity of care. A new diagnostic-communication review is included as a research milestone; its full methods were not available in this check, so no pooled treatment-effect claim is made here. [3][10][11]

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Where the field is now

As of this selective source check on October 1, 2026, FND is understood as a genuine disorder of nervous-system functioning that can often be diagnosed using positive clinical features. Structural disease can coexist with FND, and new or substantially changed symptoms still require appropriate assessment. [1][4]

Research is now increasingly divided by symptom phenotype and clinical question. That is useful progress: evidence for functional tremor does not automatically establish the diagnosis or treatment of functional seizures, functional cognitive disorder or functional visual symptoms.

The history also shows why certainty should be used carefully. FND has repeatedly been reshaped by better observation, improved diagnostic methods, changing theories and stronger treatment studies. The current model is more evidence-based than many earlier models, but it is still developing.

[!IMPORTANT] This timeline is selective. It should not be read as saying that each newer theory simply replaced an incorrect older one, or that historical diagnostic labels are interchangeable with modern FND.

On this page: Timeline · Main changes · Recent findings · Today · Sources

Research and Sources

Citation	Figure	Full citation	What it supports and limits
[1]	—	Espay AJ, Aybek S, Carson A, et al. Current concepts in diagnosis and treatment of functional neurological disorders. JAMA Neurology. 2018;75(9):1132–1141. https://doi.org/10.1001/jamaneurol.2018.1264 FND-CIT-0002.	Modern clinical framework and DSM-5 change; review, not a diagnostic study.
[2]	—	McWhirter L, Stone J, Sandercock P, Whiteley W. Hoover’s sign for the diagnosis of functional weakness: a prospective unblinded cohort study in patients with suspected stroke. Journal of Psychosomatic Research. 2011;71(6):384–386. https://doi.org/10.1016/j.jpsychores.2011.09.003 FND-CIT-0018.	Later prospective validation, not the original 1908 report.
[3]	—	Rujirussawarawong S, Ounmuang C, Aungsumart S, Kasemsuk C, Limotai N. Electrophysiology in distinguishing functional tremor from organic tremor: a systematic review and meta-analysis of diagnostic accuracy. Movement Disorders Clinical Practice. Published online June 11, 2026. DOI. PubMed. FND-CIT-0224.	2026 tremor diagnostic-accuracy synthesis; abstract-level check.
[4]	—	Hallett M, Aybek S, Dworetzky BA, McWhirter L, Staab JP, Stone J. Functional neurological disorder: new subtypes and shared mechanisms. The Lancet Neurology. 2022;21(6):537–550. https://doi.org/10.1016/S1474-4422(21)00422-1 FND-CIT-0003.	Mechanisms and subtype review; models remain incomplete.
[5]	—	Nielsen G, Stone J, Matthews A, et al. Physiotherapy for functional motor disorders: a consensus recommendation. Journal of Neurology, Neurosurgery & Psychiatry. 2015;86(10):1113–1119. https://doi.org/10.1136/jnnp-2014-309255 FND-CIT-0028.	Physiotherapy consensus, not a randomized trial.
[6]	—	Nicholson C, Edwards MJ, Carson AJ, et al. Occupational therapy consensus recommendations for functional neurological disorder. Journal of Neurology, Neurosurgery & Psychiatry. 2020;91(10):1037–1045. https://doi.org/10.1136/jnnp-2019-322281 FND-CIT-0011.	OT consensus on activity and participation.
[7]	—	Baker J, Barnett C, Cavalli L, et al. Management of functional communication, swallowing, cough and related disorders: consensus recommendations for speech and language therapy. Journal of Neurology, Neurosurgery & Psychiatry. 2021;92(10):1112–1125. https://doi.org/10.1136/jnnp-2021-326767 FND-CIT-0025.	Speech-language consensus; evidence varies by symptom.
[8]	—	Lehn A, Petrie D, Palmer D, et al. Managing functional neurological disorder: treatment recommendations for health professionals in Australia. BMJ Neurology Open. 2025;7(1):e000970. https://doi.org/10.1136/bmjno-2024-000970 FND-CIT-0076.	Australian multidisciplinary consensus; local scopes of practice vary.
[9]	—	Rutten S, Bradley-Westguard A, Nicholson TR, et al. Outcome measurement in functional neurological disorder: a qualitative study on the views of patients, caregivers and healthcare professionals. Journal of Neurology. 2025;272:189. https://doi.org/10.1007/s00415-025-12912-9 FND-CIT-0012.	Qualitative outcome priorities; not treatment-effect evidence.
[10]	—	Silva AF, Silva B. Diagnostic communication in functional neurological disorder: a systematic review and meta-analysis of patient acceptance and clinical outcomes. Patient Education and Counseling. 2026;152:109826. https://doi.org/10.1016/j.pec.2026.109826 FND-CIT-0083.	Diagnostic-communication review; bibliographic/indexed description checked, full methods pending.
[11]	—	Tolchin B, Goldstein LH, Reuber M, Stone J, Perez DL, LaFrance WC Jr, et al. Management of Functional Seizures Practice Guideline Executive Summary: Report of the AAN Guidelines Subcommittee. Neurology. 2026;106(1):e214466. https://doi.org/10.1212/WNL.0000000000214466 FND-CIT-0010.	Functional-seizure guideline; online December 2025, issue January 2026.
[12]	—	Nielsen G, Higgins R, Stone J, Coebergh J, Edwards MJ. Functional sensory symptoms and signs: a case-control study of 102 patients. Brain Communications. 2026;8(1):fcag031. https://doi.org/10.1093/braincomms/fcag031 FND-CIT-0023.	Motor-FND versus stroke case-control study; not all sensory presentations.
[13]	—	Stone J. Neurologic approaches to hysteria, psychogenic and functional disorders from the late 19th century onwards. Handbook of Clinical Neurology. 2016;139:25–36. DOI. FND-CIT-0237.	Historical review; author abstract checked, full chapter pending.
[14]	—	Hoover CF. A new sign for the detection of malingering and functional paresis of the lower extremities. JAMA. 1908;51(9):746–747. DOI. FND-CIT-0238.	Original report metadata and opening extract; historical language retained only in citation.
[15]	—	Slater E. Diagnosis of “Hysteria”. British Medical Journal. 1965;1(5447):1395–1399. DOI. FND-CIT-0239.	Historical misdiagnosis concern; metadata checked, interpretation contextualized by source 16.
[16]	—	Stone J, Smyth R, Carson A, et al. Systematic review of misdiagnosis of conversion symptoms and “hysteria”. BMJ. 2005;331:989. DOI. FND-CIT-0240.	Follow-up synthesis; older case definitions and study quality limit comparisons.
[17]	—	Stone J, LaFrance WC Jr, Brown R, Spiegel D, Levenson JL, Sharpe M. Conversion disorder: current problems and potential solutions for DSM-5. Journal of Psychosomatic Research. 2011;71(6):369–376. DOI. FND-CIT-0241.	Pre-DSM-5 criteria discussion; not the final manual.
[18]	—	Edwards MJ, Adams RA, Brown H, Pareés I, Friston KJ. A Bayesian account of “hysteria”. Brain. 2012;135(11):3495–3512. DOI. FND-CIT-0242.	Predictive-processing hypothesis, not a proven universal cause.
[19]	—	Goldstein LH, Robinson EJ, Mellers JDC, et al.; CODES study group. Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragmatic, multicentre, randomised controlled trial. The Lancet Psychiatry. 2020;7(6):491–505. https://doi.org/10.1016/S2215-0366(20)30128-0 FND-CIT-0033.	CODES randomized trial: primary and secondary findings distinguished.
[20]	—	Nielsen G, Stone J, Lee TC, et al.; Physio4FMD study group. Specialist physiotherapy for functional motor disorder in England and Scotland (Physio4FMD): a pragmatic, multicentre, phase 3 randomised controlled trial. The Lancet Neurology. 2024;23(7):675–686. https://doi.org/10.1016/S1474-4422(24)00135-2 FND-CIT-0029.	Physio4FMD randomized trial; pandemic exclusions affect interpretation.
[21]	—	Edwards MJ, Koens LH, Liepert J, Nonnekes J, Schwingenschuh P, van de Stouwe AMM, Morgante F. Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter. Clinical Neurophysiology Practice. 2024;9:69–77. https://doi.org/10.1016/j.cnp.2023.12.006 FND-CIT-0022.	Neurophysiology handbook; tests apply to selected motor phenotypes.

Review scope: This is a selective timeline, not a systematic historical review or an exhaustive search of 2026 research. Primary historical records and later interpretation are identified separately. Full-text access was uneven; the table records material access limits. Human historical, clinical and accessibility review remain pending.

Source and editorial check: October 1, 2026 · Human review pending