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Conversion disorder

Functional neurological symptom disorder (FND), formerly known as conversion disorder, is a psychiatric condition characterized by one or more symptoms affecting voluntary motor or sensory function, such as , , abnormal movements, , or non-epileptic seizures, that cannot be explained by a known neurological or medical condition. These symptoms are incompatible with recognized neurological or medical disorders, are not intentionally produced or feigned, and cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. The disorder is classified under somatic symptom and related disorders in the , and similarly as neurological symptom disorder in the , reflecting a shift from the term "conversion disorder" to emphasize its functional nature without implying a specific psychological mechanism. The diagnostic criteria for FND, as outlined in the , include evidence from clinical findings—such as positive signs like Hoover's sign for leg weakness or entrainment tests for tremors—that demonstrate inconsistency or incompatibility between the symptoms and standard medical explanations. Symptoms must not be better accounted for by another medical or , substance use, or cultural/religious practices, and they often warrant medical evaluation due to their resemblance to serious neurological illnesses. Common presentations include gait disturbances, speech impairments like dysphonia, visual or sensory deficits, and attacks resembling seizures but without epileptiform activity on EEG. Diagnosis typically involves a multidisciplinary approach, ruling out organic causes through , laboratory tests, and neurological exams, while incorporating ; often reveals functional rather than structural brain changes. Epidemiologically, as of , FND has an estimated incidence of 10–22 cases per 100,000 people per year and a minimum prevalence of 80–140 per 100,000, though estimates vary widely up to 1,600 per 100,000 due to underdiagnosis. It is more prevalent in women, with a female-to-male ratio of approximately 2:1 to 3:1, and typically onset occurs between ages 35 and 50, though it can affect individuals of any age, including children. Risk factors include a history of , physical injury, other conditions such as anxiety or , and recent stressful life events, though many patients lack identifiable triggers. Genetic, neurobiological vulnerabilities, and heightened attention to bodily symptoms may also contribute to susceptibility. The of FND is multifactorial, involving disruptions in networks responsible for , , and attention, often triggered by that alters how the generates and perceives signals. Unlike , symptoms are involuntary and real to the patient, stemming from a mismatch between and rather than structural damage. Treatment focuses on and psychological support, with (CBT) proven effective for improving symptoms and functioning, alongside physical or to retrain movement patterns. Multidisciplinary care, including education about the condition's legitimacy and addressing comorbidities, can lead to significant improvement or in 40–60% of cases with early , though chronicity can occur otherwise.

Clinical Presentation

Signs and Symptoms

Functional neurological symptom disorder (FND), formerly known as conversion disorder, is characterized by sudden onset of neurological symptoms that are inconsistent with recognized organic diseases. These symptoms typically manifest as disruptions in voluntary motor or sensory function, often appearing abruptly in the context of psychological stressors, though the symptoms themselves are not intentionally produced. Common motor disturbances include weakness or , frequently affecting a single limb or one side of the body, without evidence of muscle atrophy or reflex changes expected in organic conditions. Abnormal movements such as tremors, , or abnormalities may occur, with patients exhibiting difficulty walking or loss of balance that does not align with anatomical pathways. Speech problems, including functional dysphonia or mutism, and difficulty swallowing () are also frequent, sometimes presenting as with or globus sensation, a feeling of a lump in the . Non-epileptic seizures, or psychogenic non-epileptic seizures (PNES), involve episodes of shaking, thrashing, or unresponsiveness lasting longer than typical epileptic seizures, without EEG abnormalities or postictal confusion. Sensory deficits commonly include blindness, , or numbness, often in non-anatomical distributions such as a hemisensory loss that splits precisely at the midline or ends sharply at a , defying dermatomal or peripheral patterns. These sensory losses lack the gradual progression or corresponding neurological findings seen in structural lesions. La belle indifference, where individuals display an apparent lack of concern disproportionate to the severity of their symptoms, was formerly considered characteristic but is not a reliable diagnostic feature, being absent in most cases and not included in criteria. Positive signs supporting a functional include Hoover's sign, in which a with apparent leg weakness fails to generate involuntary hip extension on the affected side when flexing the contralateral hip against resistance, indicating preserved automatic motor function. Symptoms often vary over time, fluctuating with attention or suggestion, and may resolve temporarily during distraction, further highlighting their inconsistency with fixed neurological deficits.

Associated Features

Functional neurological symptom disorder is frequently accompanied by various psychiatric comorbidities, which can complicate the clinical picture and influence treatment approaches. is one of the most common, with prevalence rates reported between 19% and 77% across studies and populations. Anxiety disorders co-occur in 21% to 75% of cases, while (PTSD) affects 8% to 63% of individuals with the disorder. are also prevalent, with rates up to 50% in some studies, and personality disorders may be present in more than 50% of cases, though exact rates vary across studies. These comorbidities often exacerbate the overall symptom burden and are associated with histories of in many cases. Behavioral patterns in functional neurological symptom disorder may include elements of secondary gain, where unconscious benefits such as avoidance of responsibilities or strengthened interpersonal support reinforce symptom persistence—for instance, a sudden might inadvertently preserve a strained . Unlike , which involves conscious fabrication of symptoms for external incentives like financial compensation, secondary gain in functional neurological symptom disorder operates outside of deliberate intent. , involving intentional symptom production for psychological needs like attention, must also be differentiated, as it lacks the incompatibility with known neurological pathways central to functional neurological symptom disorder. Cognitive features commonly associated with functional neurological symptom disorder include heightened dissociation, where individuals experience a detachment from their symptoms or reality, contributing to the disorder's maintenance. Suggestibility, particularly hypnotic suggestibility, is elevated compared to the general population and may play a role in symptom onset or exacerbation under . In rarer instances, functional neurological symptom disorder presents alongside multiple functional symptoms, overlapping with broader functional somatic syndromes such as or gastrointestinal issues, leading to polysymptomatic presentations that require careful assessment. The presence of these associated features often profoundly impacts daily functioning, leading to social withdrawal, strained relationships, and reduced occupational or academic performance. For example, motor symptoms may limit , fostering and on others, while comorbid mood disturbances can intensify emotional distress and hinder recovery. Overall, these accompaniments underscore the need for a holistic beyond the primary neurological-like symptoms.

and Pathophysiology

Psychological Mechanisms

Conversion disorder has been conceptualized through psychodynamic lenses as a symbolic manifestation of unresolved internal conflicts, where emotional distress is transformed into physical symptoms. In classical Freudian theory, symptoms arise from the repression of unacceptable thoughts or desires, particularly those rooted in sexual or aggressive drives, leading to a "conversion" of energy into expressions. Freud and Breuer described —now encompassing conversion disorder—as resulting from "strangulated ," wherein intense emotions associated with traumatic memories are dammed up due to incompatibility with conscious awareness, finding outlet through bodily symptoms that symbolically represent the repressed content. For instance, might symbolize an unconscious wish to avoid a forbidden action, serving as a formation that both expresses and conceals the conflict. Modern psychological models build on these foundations by integrating stress-diathesis frameworks, positing that conversion symptoms emerge from the between inherent vulnerabilities and precipitating psychosocial stressors. Pierre Janet's early diathesis-stress model emphasized a constitutional weakness in psychic synthesis, rendering individuals prone to under emotional overload from , resulting in "fixed ideas" that manifest as fixed symptoms. Contemporary views extend this to include cognitive-behavioral elements, such as biases toward bodily sensations and maladaptive strategies like avoidance or , which amplify responses into symptom formation. Acute , often interpersonal in nature, triggers as a protective , diverting from overwhelming emotions to physical incapacitation, thereby resolving conflicts indirectly—such as through symptom-induced escape from unbearable situations. Predisposing factors like insecure attachment styles and childhood adversity further heighten vulnerability by impairing emotion regulation and fostering dysfunctional . Individuals with disorganized or anxious attachment, often stemming from early inconsistent caregiving, exhibit heightened sensitivity to , increasing the likelihood of responses in adulthood. Studies indicate that childhood physical or is reported in up to 70% of conversion disorder cases, compared to lower rates in controls, suggesting these experiences disrupt attachment security and promote as a learned mechanism. For example, survivors of adversity may develop avoidant patterns that prioritize physical symptoms over verbal processing of , perpetuating a cycle of emotional constriction. Empirical evidence underscores the role of identifiable stressors in symptom onset, with reviews of clinical studies reporting psychological precipitants in 70-90% of cases, often involving interpersonal conflicts, , or within months preceding symptoms. In one systematic analysis, adverse life events were documented in 91% of patients, frequently linked to "" scenarios where symptoms facilitate avoidance of acute distress, such as family discord or academic pressure. These findings support the hypothesis that serves an adaptive function in the short term, allowing unconscious resolution of stressors through physical , though it may entrench if underlying vulnerabilities remain unaddressed.

Neurobiological Factors

Functional neuroimaging studies have identified distinct patterns of brain activation associated with conversion disorder, particularly in motor and sensory symptoms. (fMRI) research demonstrates increased activity in the and , coupled with decreased hippocampal engagement, during symptom-related tasks, suggesting involvement of executive control and emotional regulation circuits. A of imaging studies on motor conversion disorders reveals consistent hypoactivation in cortical motor regions and altered functional connectivity within the , which processes attention and , during voluntary movement attempts. These findings indicate that symptoms may arise from disrupted integration between prefrontal inhibitory mechanisms and subcortical motor pathways, mimicking voluntary inhibition patterns observed in healthy individuals performing similar tasks. Autonomic dysregulation represents another key neurobiological feature in conversion disorder. Studies using heart rate variability (HRV) analysis in patients with functional movement disorders show reduced HRV, reflecting an imbalance with diminished parasympathetic input and heightened sympathetic dominance, which correlates with symptom severity. In pediatric populations, individuals with conversion symptoms exhibit elevated autonomic arousal at rest and during cognitive tasks, alongside abnormal cortisol responses to stress, indicating hypersensitivity in the hypothalamic-pituitary-adrenal axis. These autonomic alterations underscore a physiological basis for symptom exacerbation under stress, distinct from purely psychological influences. Recent research in the 2020s has advanced understanding through (EEG) and computational models. EEG studies reveal disrupted in conversion disorder, pointing to impaired cortical mapping of intended actions. frameworks, applied to functional neurological disorders, propose that symptoms persist due to maladaptive priors—neurally encoded expectations—that override sensory , leading to aberrant precision weighting in Bayesian brain processes. Neurodevelopmental factors, such as prior mild , further heighten vulnerability by altering baseline neural plasticity and stress reactivity, as evidenced in longitudinal analyses. Emerging from 2023–2025 reviews also implicates neurotransmitter imbalances (e.g., and serotonin dysregulation), inflammatory markers, and genetic predispositions in contributing to the neurobiological vulnerabilities underlying FND .

Diagnosis

Diagnostic Criteria

The diagnostic criteria for conversion disorder, now primarily termed functional neurological symptom disorder (FND) in contemporary classifications, are outlined in the DSM-5-TR and , reflecting a shift toward positive identification of functional symptoms rather than exclusionary approaches. In the DSM-5-TR, published by the in 2022, the disorder is diagnosed based on four essential criteria: (A) one or more symptoms of altered voluntary motor or sensory function; (B) clinical findings that provide evidence of incompatibility between the symptom and recognized neurological or medical conditions (e.g., positive signs such as Hoover's sign for weakness or inconsistency in ); (C) the symptom or deficit not better explained by another medical or ; and (D) the symptom or deficit causing clinically significant distress or impairment in social, occupational, or other important areas of functioning, or warranting medical evaluation. These criteria emphasize demonstrable inconsistencies or internal inconsistencies in symptoms, such as non-anatomic sensory distributions or distractibility, to support the without requiring proof of psychological causation. Specifiers in the DSM-5-TR further delineate the presentation, including types such as with or , abnormal movement (e.g., or gait disorder), swallowing symptoms, speech symptoms, attacks or seizures, or , special sensory symptoms (e.g., visual or auditory), or mixed symptoms. Temporal specifiers distinguish acute episodes (symptoms present less than 6 months) from persistent (chronic) cases (6 months or longer), aiding in prognostic assessment. The criteria also accommodate cultural variations in symptom expression, recognizing that certain manifestations, such as trance-like states or culturally specific complaints, may align with FND if they meet the core incompatibility and distress requirements, as clarified in recent literature emphasizing equitable application across diverse populations. In the , effective since 2022 from the , the condition is classified as dissociative neurological symptom disorder (code 6B60) within the chapter, characterized by the presence of one or more motor, sensory, or cognitive symptoms implying a neurological condition, such as , blindness, or seizures, that are incompatible with established neurological or medical conditions. The symptoms must not be better explained by another , must not be intentionally produced or feigned, and must be associated with significant distress, impairment, or need for medical evaluation; unlike prior versions, prioritizes positive functional signs (e.g., entrainment of or variability with ) over mere exclusion of organic disease. Subtypes include those with /, , , or non-epileptic seizures, without a mandatory link to psychological factors but allowing association with identifiable stressors if present. Historically, the DSM-IV (1994) required symptoms to be "linked to psychological factors" and used the term "conversion disorder" with a focus on la belle indifférence (lack of concern), but the (2013) and DSM-5-TR eliminated these, renaming it FND to reduce stigma and etiologic assumptions while introducing the incompatibility criterion for more reliable . Similarly, classified it under dissociative [conversion] disorders with subtypes for motor, sensory, and seizures, describing symptoms that suggest but are not intentionally produced to mimic organic disease, but streamlined this into a single category with emphasis on verifiable functional inconsistencies, aligning with neuroscientific and promoting earlier intervention. These evolutions, informed by high-impact studies from 2010 onward, underscore a on using affirmative clinical for .

Differential Diagnosis

The differential diagnosis of conversion disorder, also known as functional neurological symptom disorder, requires a systematic approach to exclude organic neurological conditions and differentiate from psychiatric mimics, ensuring that symptoms are not attributable to known medical or intentional causes. This process begins with a thorough clinical to identify potential stressors, followed by and targeted investigations, often involving multidisciplinary input from to confirm the functional nature of symptoms. Key organic neurological conditions to exclude include , multiple sclerosis, epilepsy, and peripheral neuropathies such as Guillain-Barré syndrome. Neuroimaging with MRI is essential to rule out structural lesions like those seen in or multiple sclerosis, while EEG helps differentiate functional seizures from epileptic events, and EMG/nerve conduction studies identify peripheral neuropathies. Laboratory evaluations, including cerebrospinal fluid analysis, typically yield normal results in conversion disorder but may show abnormalities (e.g., elevated protein in Guillain-Barré) that support an alternative diagnosis. Psychiatric differentials encompass , , and , distinguished primarily by the level of distress, intentionality, and symptom focus. In , patients exhibit persistent disproportionate anxiety about multiple symptoms, unlike the often acute, isolated neurological presentation in conversion disorder with potential la belle indifference. involves deliberate symptom fabrication for external incentives, contrasting the involuntary mechanisms of conversion, while centers on preoccupation with imagined appearance flaws rather than motor or sensory deficits. , another mimic, features intentional symptom production for psychological gain without external rewards. A stepwise diagnostic approach emphasizes positive "rule-in" features for conversion disorder alongside exclusions. Bedside neurological tests are crucial, such as for tremors—where the abnormal adopts the rhythm of a voluntary frequency—or distractibility maneuvers, in which symptoms like or sensory loss diminish when patient attention is diverted (e.g., via cognitive tasks). These , combined with inconsistent examination findings, support a functional when is negative. Neurological consultation facilitates this, particularly in ambiguous cases. Challenges arise in atypical presentations, such as post-COVID functional neurological symptoms, where overlapping features with (e.g., fatigue, dizziness) complicate differentiation; 2024 guidelines stress reliance on rule-in functional signs like distractibility and to avoid misattribution, while continuing to exclude evolving organic sequelae through serial testing.

Management and Treatment

Therapeutic Approaches

Cognitive-behavioral therapy (CBT) serves as the primary evidence-based psychological intervention for conversion disorder, targeting maladaptive thoughts and behaviors associated with symptoms. Key techniques include to reframe symptoms as reversible disruptions in brain function rather than permanent damage, thereby reducing distress and secondary gains, alongside graded and behavioral experiments to restore normal motor or sensory function. A of randomized controlled trials demonstrated that CBT yields moderate to large effect sizes in reducing symptom severity, with 49% of s showing symptomatic improvement in one retrospective study. Physiotherapy and are essential rehabilitative approaches, particularly for motor symptoms such as , , or disturbances in conversion disorder. These therapies emphasize motor retraining through techniques, where patients perform movements during divided attention to bypass habitual dysfunction, and specific interventions like to normalize limb perception or to promote use of affected . A multicenter established that specialist physiotherapy significantly improves motor function and daily activities compared to usual care, with sustained benefits observed at 6-month follow-up. Consensus guidelines further recommend integrating these methods within a multidisciplinary framework to address functional limitations effectively. A 2024 demonstrated that combining physiotherapy and effectively improves symptoms and physical functioning in individuals with functional . Pharmacotherapy does not target conversion disorder symptoms directly, as no medications have demonstrated efficacy for core neurological manifestations; instead, it is reserved for managing comorbid conditions such as anxiety or . Selective serotonin inhibitors (SSRIs), for instance, may alleviate associated mood symptoms, but systematic reviews indicate insufficient evidence for their use in symptom resolution alone. A comprehensive review of pharmacological interventions in functional neurological disorders underscores this limited role, emphasizing that drugs should complement rather than replace psychotherapeutic or rehabilitative strategies. Emerging treatments like repetitive (rTMS) show promise for refractory cases of conversion disorder, particularly those with persistent motor symptoms, by modulating cortical excitability in the motor regions. Pilot studies applying high-frequency rTMS to the have reported rapid symptom alleviation and enhanced , with case series demonstrating functional improvements in weakness following brief sessions. Recent clinical trials from 2023 to 2025 further support its feasibility as an adjunct, though larger randomized studies are needed to confirm long-term efficacy.

Supportive Interventions

Patient education forms a of supportive interventions for conversion disorder, focusing on elucidating the functional origins of symptoms to alleviate and minimize iatrogenic harm from misguided medical pursuits. By framing symptoms as arising from disruptions in function rather than structural , clinicians help patients recognize their experiences as genuine yet modifiable, promoting in the diagnostic and encouraging active participation in care. The "brain network" model, which posits that symptoms stem from altered connectivity within neural circuits—such as heightened limbic-motor interactions—serves as an accessible explanatory tool, often delivered through educational materials, videos, or discussions to normalize the condition and reduce self-blame. Family therapy and broader social support mechanisms address interpersonal factors that can sustain symptoms, such as secondary gains from illness roles or strained relational dynamics. These interventions involve engaging family members to enhance understanding of the disorder, foster empathetic communication, and diminish inadvertent reinforcement of symptoms through overprotection or . Social support networks, including peer groups or community resources, further bolster by countering isolation and providing validation, thereby facilitating emotional adjustment and symptom reduction. Multidisciplinary team involvement ensures coordinated care across specialties, integrating neurologists for symptom validation, psychiatrists for psychological oversight, physical therapists for motor retraining, and occupational therapists for functional restoration. For sensory symptoms like , non-pharmacological techniques—such as graded exposure and sensory re-education—are incorporated to improve tolerance without escalating investigations. Return-to-work programs, often led by occupational specialists, emphasize gradual reintegration through activity pacing and workplace accommodations, aiming to restore vocational independence and prevent chronic disability. In acute presentations with sudden symptom onset, crisis intervention prioritizes rapid stabilization, frequently via inpatient admission to a specialized unit for monitoring and environmental control. This approach mitigates risks like self-harm or symptom escalation while initiating supportive measures promptly. Guidelines from 2024 underscore the need to curtail unnecessary diagnostic tests during crises, as such procedures can entrench illness beliefs and prolong recovery, advocating instead for focused clinical assessment to affirm the functional diagnosis early. These supportive strategies complement therapeutic approaches by creating an enabling context for symptom resolution and functional improvement.

Prognosis and Outcomes

Short-Term Outcomes

In acute cases of conversion disorder, a substantial proportion of patients , with estimates indicating that 50% to 90% achieve short-term resolution of symptoms following reassurance and resolution of precipitating stressors. This remission often occurs within weeks, particularly when symptoms are linked to identifiable psychological stressors that are subsequently addressed. Several factors predict poorer short-term outcomes, including the presence of multiple symptoms and delayed . For instance, a higher number of physical symptoms has been associated with reduced likelihood of early , as observed in longitudinal studies of functional . Similarly, delays in increase the risk of persistent symptoms and lower remission rates in the initial months. Cases with symptom onset of less than 3 months generally show better short-term resolution compared to those with longer durations prior to intervention. Relapse risks remain notable in the first 6 to 12 months following initial remission, with longitudinal cohort studies reporting recurrence rates of 20% to 25% during this period. These recurrences often involve new or similar symptoms triggered by ongoing stressors. Early intervention, such as prompt (), has been shown to accelerate recovery; a 2025 of treatment outcomes in functional confirmed faster symptom reduction with timely initiation.

Long-Term Prognosis

The long-term prognosis of conversion disorder, now often termed functional neurological disorder (FND), varies significantly, with approximately 20-25% of cases developing a chronic course that persists beyond one year and may evolve into persistent functional disorders or characterized by ongoing unexplained physical symptoms accompanied by excessive thoughts, feelings, or behaviors related to them. In such instances, symptoms like motor weakness or can recur in altered forms, contributing to prolonged if untreated. Factors such as comorbid psychiatric conditions (e.g., or anxiety) and socioeconomic stressors, including financial hardship or lack of support, exacerbate this trajectory by hindering recovery and increasing the risk of symptom perpetuation. For example, long-term studies indicate rates as high as 41% among individuals with FND, reflecting substantial occupational and reduced . Prognosis is generally better in children, with remission rates up to 75% in pediatric cases, compared to adults where chronicity is more common. Despite these challenges, positive outcomes are achievable with early and comprehensive , as evidenced by follow-up studies showing that around 60-70% of patients achieve functional or significant improvement at 2- to 5-year marks, particularly those receiving multidisciplinary . Short-term symptom resolution often predicts better long-term trajectories, with sustained gains in daily functioning reported in cohorts adhering to therapeutic regimens. Recent research from 2024-2025 includes explorations of interventions like subdissociative-dose for acute exacerbations in emergency settings. Emerging digital tools support long-term management through ; for instance, apps like myFND allow users to track symptoms, moods, and self-management strategies. Ongoing research is needed to evaluate their role in standard care.

Epidemiology

Prevalence and Incidence

Conversion disorder, also known as functional neurological symptom disorder, exhibits varying rates depending on the studied. In general populations, minimum estimates are 80–140 per 100,000 individuals, with a possible range of 50–1,600 per 100,000, based on recent systematic reviews and epidemiological surveys. These figures reflect the disorder's relatively low occurrence outside clinical settings. In specialized medical contexts, rates are notably higher. Among patients presenting with unexplained neurological symptoms in clinics, conversion disorder accounts for 5–15% of cases. In general hospitals, approximately 5% of patients meet full diagnostic criteria, while 20–25% exhibit individual conversion-like symptoms. Incidence rates, derived from and population-based studies, typically fall between 10 and 22 new cases per 100,000 individuals annually. These rates can spike following major stressors, such as trauma or pandemics; for instance, during the 2020–2022 period, clinics reported increased incidences of functional , with one tertiary center noting an 8.2% rate among new referrals, up from pre-pandemic baselines. Underreporting remains a significant challenge due to associated , which discourages individuals from seeking or disclosing care, leading to underestimation in community surveys. As of , recent systematic reviews indicate stable global incidence and rates.

Demographic Variations

Conversion disorder exhibits notable disparities, with estimates indicating it is 2-3 times more common in s than males. The female predominance is less pronounced in children and individuals over 50 years, where the ratio approaches 1:1. This difference is often attributed to patterns that encourage women to express emotional distress through symptoms rather than verbalization, influenced by -weighted risk factors such as higher rates of childhood and among women. Age patterns in conversion disorder show a peak incidence during young adulthood, typically between 20 and 40 years, when stressors like career transitions and relationships are prominent. The disorder is rarer in children under 10 years, with presentations before this age often linked to acute but comprising less than 5% of cases in pediatric settings. Similarly, it is infrequent in the elderly over 70, where neurological conditions more commonly mimic symptoms, leading to underdiagnosis or misattribution. Cultural influences significantly shape the expression of conversion disorder, with symptom manifestations varying by societal norms; for instance, states and trance-like episodes are more prevalent in some and Middle Eastern cultures, such as among communities where integrates with motor symptoms like , contrasting with predominantly paralytic or sensory deficits in Western contexts. These variations reflect culturally sanctioned ways of articulating distress, and appears higher in collectivist societies where communal harmony suppresses direct emotional expression, as evidenced by elevated rates in regions like and . Socioeconomic factors contribute to elevated rates of conversion disorder in lower socioeconomic status (SES) groups, where chronic stress from financial instability and limited access to mental health resources exacerbates vulnerability. Recent studies, including a 2023 analysis in , report 1.5-2 times higher prevalence among individuals from low-SES backgrounds compared to higher-SES counterparts, often compounded by rural residence and lower education levels.

History and Evolution

Historical Development

The concept of conversion disorder traces its roots to ancient medical observations of , a condition characterized by unexplained neurological symptoms predominantly affecting women. Around 400 BCE, provided one of the earliest systematic descriptions, attributing hysteria to a "wandering " that detached from its normal position and migrated through the body, causing suffocation, , and other somatic complaints due to lack of moisture or displacement. This uterine theory dominated Western medicine for centuries, influencing treatments like , , or physical relocation of the organ to restore balance. In the , significant progress occurred through the clinical work of at the Salpêtrière Hospital in , where he systematically studied as a rather than a purely gynecological one. Charcot's demonstrations, often using to induce and alleviate symptoms, highlighted distinct features of hysterical attacks—such as prolonged convulsions without loss of consciousness—allowing him to differentiate them from epileptic seizures and other organic conditions. His public lectures and iconographic documentation popularized as a verifiable , shifting focus toward neurophysiological mechanisms while emphasizing environmental and suggestive influences. The early 20th century saw a pivotal psychological reframing with the 1895 publication of by and , which proposed that hysterical symptoms arose from repressed traumatic memories converted into physical manifestations. Through case studies, including the famous "Anna O.," they introduced the cathartic method—a form of conducted under —to access and discharge these unconscious conflicts, achieving symptom relief without physical intervention. This work established hysteria as a disorder of psychological origin, emphasizing the role of emotional catharsis over anatomical pathology. Mid-20th-century developments, particularly during , further illuminated trauma's etiological role through widespread cases of "" or combat fatigue among soldiers, manifesting as conversion symptoms like mutism, blindness, and in the absence of injury. These incidents, affecting tens of thousands, linked acute from to symptom onset and revealed mass sociogenic outbreaks, where group suggestion amplified unexplained neurological complaints in military units. Such observations reinforced the disorder's responsiveness to environmental stressors and therapeutic reassurance.

Terminological Changes

Following , the (APA) introduced the term "hysterical neurosis, conversion type" in the first edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-I, 1952), reflecting the psychoanalytic influences of the era where symptoms were viewed as symbolic expressions of unconscious conflicts transforming psychological distress into physical manifestations. This classification positioned conversion symptoms within the broader category of psychoneurotic disorders, emphasizing etiological theories rooted in Freudian concepts of . By the third edition (DSM-III, 1980), the shifted away from the stigmatizing label of "," introducing "conversion disorder" as a distinct somatoform disorder to prioritize observable symptoms over inferred psychological mechanisms and reduce pejorative connotations associated with historical terms. This change aimed to foster a more descriptive, atheoretical approach aligned with the evolving emphasis on reliability in psychiatric diagnosis. The fifth edition (DSM-5, 2013) further refined the nomenclature to "functional neurological symptom disorder (conversion disorder)," incorporating the parenthetical alternative to maintain continuity while highlighting positive neurological signs—such as inconsistency or distractibility in symptoms—over mere exclusions of , thereby integrating emerging neuroscientific understandings of altered . In the text revision (DSM-5-TR, ), updates clarified specifiers for symptom types (e.g., with weakness or , abnormal movement) to enhance clinical precision and reflect advances in evidence demonstrating aberrant neural activation patterns. Parallel evolutions occurred in the International Classification of Diseases (ICD), where the tenth revision (ICD-10, 1992) coded conversion disorder as F44.4 under dissociative and conversion disorders, framing it as motor or sensory deficits linked to psychological factors without organic basis. The eleventh revision (ICD-11, approved 2019 and effective 2022) reclassified it as 6B60 "dissociative neurological symptom disorder" within the dissociative disorders chapter, emphasizing the role of dissociation in symptom generation and incorporating qualifiers for specific manifestations like weakness or seizures to align with contemporary neurobiological insights.

References

  1. [1]
    Functional Neurologic Disorder - StatPearls - NCBI Bookshelf - NIH
    Functional neurologic disorder, formally conversion disorder, is a psychiatric disorder characterized by signs and symptoms affecting sensory or motor function.Introduction · Epidemiology · History and Physical · Differential Diagnosis
  2. [2]
    Functional neurologic disorder/conversion disorder - Mayo Clinic
    This disorder includes nervous system symptoms affecting movement or the senses that are not caused by medical disease. Treatment can help with recovery.Diagnosis · Treatment · Preparing For Your...
  3. [3]
    [PDF] Functional Neurological Symptom Disorder (Conversion Disorder)
    In Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the term “Functional Neurological Symptom Disorder” was added in parentheses after the DSM-IV ...
  4. [4]
    Conversion Disorders Clinical Presentation: History, Physical, Causes
    Jul 20, 2021 · Diagnostic criteria (DSM-5) · One or more symptoms of altered voluntary motor or sensory function. · Physical findings provide evidence of ...History · Physical · Mental Status Examination
  5. [5]
    Functional Neurological Disorder (Formerly Conversion Disorder)
    Functional neurological disorder (FND), formerly conversion disorder, is a condition in which a mental health issue disrupts how your brain works.Symptoms And Causes · Diagnosis And Tests · Management And Treatment
  6. [6]
    Epidemiology - PubMed
    FND symptoms are disabling and associated with significant distress. They are more common in women and have a peak incidence between the ages of 35 and 50; ...
  7. [7]
    Functional Neurologic Disorder
    Jul 19, 2024 · Symptoms of functional seizures most often begin in a person's late 20s. The fundamental of FND involve biological and sociological factors.What is functional neurologic... · How is functional neurologic...
  8. [8]
    A review of functional neurological symptom disorder etiology and ...
    Predisposing factors include trauma or psychiatric symptoms, somatic symptoms, illness exposure, symptom monitoring and neurobiological factors. Neurobiological ...
  9. [9]
    Diagnosis and management of functional neurological disorder
    Jan 24, 2022 · Rehabilitative interventions (physical and occupational therapy) are treatments of choice for functional ... Conversion Disorder / therapy* ...
  10. [10]
    Functional neurologic disorder/conversion disorder - Mayo Clinic
    Jan 11, 2022 · Symptoms · Weakness or paralysis · Abnormal movement, such as tremors or difficulty walking · Loss of balance · Difficulty swallowing or feeling "a ...
  11. [11]
    Conversion Disorder: The Brain's Way of Dealing with Psychological ...
    Jan 16, 2019 · Common symptoms include blindness, paralysis, dystonia, anesthesia, inability to speak, difficulty swallowing, incontinence, balance problems, ...
  12. [12]
    Progress in understanding conversion disorder - PMC - NIH
    The core feature of conversion disorder is a deficit or distortion in neurological functioning, or symptoms suggesting a general medical condition that is not ...
  13. [13]
    (PDF) A Psychodynamic Perspective on Treatment of Patients with ...
    Importance Freud argued that in conversion disorder (CD) the affect attached to stressful memories is “repressed” and “converted” into physical symptoms ...
  14. [14]
    Etiology, Pathogenesis, and Therapy According to Pierre Janet ...
    Apr 30, 2018 · According to Janet's diathesis-stress model of dissociative disorders and conversion disorders, therapy for fixed ideas is more important than ...
  15. [15]
    Full article: Uncovering the etiology of conversion disorder
    Jan 13, 2016 · Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors ...
  16. [16]
    Stressful life events and maltreatment in conversion (functional ...
    We systematically reviewed controlled studies reporting stressors occurring in childhood or adulthood, such as stressful life events and maltreatment (including ...
  17. [17]
    Attachment State of Mind and complex traumatization in patients ...
    The main aim of the present study was to investigate the Attachment SoM and the quality of traumatic events occurred during childhood of patients with FMD by ...
  18. [18]
    Childhood sexual abuse predicts treatment outcome in conversion ...
    Feb 7, 2020 · Childhood sexual abuse is significantly associated with poor treatment outcome for physical symptoms in patients with conversion disorder/FND.
  19. [19]
    Childhood Abuse in Patients With Conversion Disorder
    Conversion disorder is characterized by the presence of deficits affecting the voluntary motor or sensory functions. These symptoms suggest neurological or ...
  20. [20]
    Psychological Stressors in Conversion Disorder - NEJM Journal Watch
    Jul 29, 2016 · The role of stressors in CD is controversial, and DSM-5 has removed the diagnostic criterion of a stressor near the time of symptom onset. To ...Missing: studies 70-90%<|control11|><|separator|>
  21. [21]
    Life events and escape in conversion disorder - PMC - NIH
    Although our finding of elevated rates of stressors in the year before onset of CD supports the psychological model it of course does not establish ...
  22. [22]
    Imaging Shows Brain Changes In Conversion-Disorder Patients
    Notably, compared with controls, conversion-disorder subjects showed increased dorsolateral prefrontal cortex activity, decreased hippocampus activity, enhanced ...
  23. [23]
    Neural correlates of conversion disorder: overview and meta ...
    Jun 10, 2016 · With this study, we are strengthening the evidence for neurobiological factors of MCD and hope to provide a first attempt at substantiating ...
  24. [24]
    Neuroimaging in Functional Neurological Disorder: State of the Field ...
    A growing number of quality neuroimaging studies using a variety of methodologies have shed light on the emerging pathophysiology of FND.
  25. [25]
    Analysis of Heart Rate Variability in Functional Movement Disorder ...
    Reduced HRV can be reflective of autonomic dysregulation, with decreased parasympathetic input relative to sympathetic input. While reduced HRV has been ...
  26. [26]
    Reduction of autonomic regulation in children and adolescents with ...
    Results: Children and adolescents with conversion symptoms displayed higher autonomic arousal than did the controls, both at baseline and during task conditions ...Missing: dysregulation | Show results with:dysregulation
  27. [27]
    Neuroimaging in Functional Movement Disorders - PMC - NIH
    Feb 12, 2019 · Functional imaging techniques such as fMRI and PET allow abnormalities in regional brain activation, and functional connectivity between brain ...
  28. [28]
    The neurobiology of functional neurological disorders characterised ...
    Mar 15, 2023 · We review the neurobiology of Functional Neurological Disorders (FND), ie, neurological disorders not explained by currently identifiable histopathological ...
  29. [29]
    Understanding Functional Neurological Disorder: Recent Insights ...
    Functional neurological disorder (FND), formerly called conversion disorder, is a condition characterized by neurological symptoms that lack an identifiable ...1. Introduction · 8. Neuroimaging In... · 9. Discussion
  30. [30]
    Functional neurological disorder: defying dualism - Stone - 2024
    Jan 12, 2024 · The dropping of the requirement for a recent stressful event in the DSM-5, and the change of the name of the condition from “conversion disorder ...
  31. [31]
    Conversion Disorders Differential Diagnoses - Medscape Reference
    Jul 20, 2021 · The differential diagnosis of conversion disorders is highly dependent on the manner in which the patient presents.
  32. [32]
    Functional neurological symptom disorder (conversion disorder) in ...
    Aug 1, 2023 · Functional neurological symptom disorder (conversion disorder) is characterized by neurologic symptoms such as weakness, abnormal movements, or ...
  33. [33]
    Conversion Disorder - an overview | ScienceDirect Topics
    However, in the general population, estimates for the prevalence of conversion disorder are only between 0.011% and 0.5%. There has been some documentation that ...
  34. [34]
    Functional Neurologic Disorder | Pediatric Care Online
    Sep 11, 2024 · Differential Diagnosis. Functional neurological disorder is often confused with factitious disorder or malingering. Factitious disorder:.
  35. [35]
    Functional movement disorders - UpToDate
    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) classifies abnormal functional ...
  36. [36]
    A Review and Expert Opinion on the Neuropsychiatric Assessment ...
    Aug 11, 2020 · Positive signs for functional tremor include distractibility, entrainment (abnormal movements that take on the frequency of volitional ...
  37. [37]
    Diagnostic challenges of functional neurological disorders after ...
    Nov 21, 2022 · Functional neurological disorders have rarely been described in patients recovering from Covid-19 or after vaccination but they are probably under diagnosed.
  38. [38]
    Optimizing outcomes when treating functional neurological disorder ...
    Jun 5, 2024 · A prior diagnosis of FND should not impact the SOP for evidence-based care over concerns regarding the validity of their symptom presentation.
  39. [39]
    Systematic review of psychotherapy for adults with functional ...
    A recent meta-analysis of 16 studies suggests that CBT is potentially beneficial for the subtype of PNES,12 with 47% of eligible participants being seizure free ...
  40. [40]
    Outpatient CBT for Motor Functional Neurological Disorder and ...
    Aug 30, 2019 · This study examined sociodemographic and clinical characteristics, treatment outcomes, and treatment dropout among patients with and without mFND who received ...
  41. [41]
    Physiotherapy for functional motor disorders: a consensus ...
    There is growing evidence that physiotherapy is an effective treatment, but the existing literature has limited explanations of what physiotherapy should ...
  42. [42]
    Transcranial magnetic stimulation as a primer for rapid improvement ...
    Jul 7, 2025 · Transcranial magnetic stimulation as a primer for rapid improvement in functional neurological disorder: a case series. BMJ Neurol Open. 2025 ...<|control11|><|separator|>
  43. [43]
    A Customized Neural Transcranial Magnetic Stimulation Target for ...
    Jun 23, 2025 · This study aims to (1) test the preliminary efficacy of high-frequency rTMS provided to a customized neural target to treat functional disability among ...Missing: conversion | Show results with:conversion
  44. [44]
    Functional Neurological Disorder - Mass General Advances in Motion
    Aug 3, 2021 · Depression, anxiety, trauma-related symptoms are also prevalent; The limbic and salience brain network are hyperconnected to motor areas ...
  45. [45]
    Functional Neurological Disorder Program - Stanford Medicine
    The Functional Neurological Disorder Program in the Department of Psychiatry and Behavioral Sciences at Stanford treats patients suffering from FND.What Is Fnd? · Our Services · Psychogenic Seizures: What...<|control11|><|separator|>
  46. [46]
    Conversion Disorders Treatment & Management
    Jul 20, 2021 · Insight Oriented Supportive therapy: Offers the client support and helps the patient to gain insight into their condition and possible triggers.
  47. [47]
    Conversion Disorder | American Journal of Psychiatry
    Sep 1, 2006 · Anecdotal studies report improvement with selective serotonin reuptake inhibitors (SSRIs), beta-blockers, analgesics, and benzodiazepines (60) .
  48. [48]
    Treatment for Patients With a Functional Neurological Disorder ...
    Apr 1, 2018 · Cognitive-behavioral therapy (CBT) has also been shown to be beneficial in treating functional neurological disorders (54).
  49. [49]
    Functional Neurological Disorders | PM&R KnowledgeNow
    Jul 3, 2025 · Conversion disorder (CD) is a condition now also referred to as Functional Neurological Symptom Disorder (FNSD) classified in DSM-5 as related to Somatic ...
  50. [50]
    Multidisciplinary rehabilitation for functional neurological disorder ...
    Jun 13, 2025 · This case illustrates the effectiveness of acute rehabilitative care in functional neurological disorders, highlighting the significance of early intervention.
  51. [51]
    [PDF] Managing Functional Neurological Disorders - FND Australia
    May 20, 2024 · A State-wide Recommendation for an FND Clinical Pathway. Queensland, Australia. May 2024. Page 2. - 2 -. This consensus recommendation has been ...
  52. [52]
    ED and Inpatient Use and Costs in Adult and Pediatric Functional ...
    Oct 26, 2020 · Appropriate treatment of FNDs starts with diagnostic debriefing, avoidance of unnecessary investigations, avoidance of pharmacotherapy ...<|control11|><|separator|>
  53. [53]
  54. [54]
    Conversion disorder: advances in our understanding - PMC - NIH
    Four types of conversion disorder are specified: those with motor symptoms or deficits, those with sensory symptoms or deficits, those with pseudo-seizures and ...<|control11|><|separator|>
  55. [55]
    Conversion Disorder and Functional Weakness: Long-Term Outcomes
    Jul 31, 2019 · Poor prognostic features included somatization disorder, high number of physical symptoms, and high pain scores and low general health scores ...
  56. [56]
    When neurologists diagnose functional neurological disorder, why ...
    However, in adults and children with delayed diagnosis the prognosis of FND is poor, with low remission rates at follow-up, and rates of job loss and social ...
  57. [57]
    Treatment outcomes in functional neurological disorder
    Oct 5, 2025 · Motor symptom severity scores​​ 17 studies reported a mean improvement of –14.5 points (95% CI: –18.89 to –10.12) on a 0 to 100 scale ...
  58. [58]
    Prognosis of functional neurologic disorders - PubMed
    In most studies, functional motor symptoms and psychogenic nonepileptic attacks remain the same or are worse in the majority of patients at follow-up.
  59. [59]
    Functional neurological disorder is a feminist issue
    84–86 Research comparing long-term prognosis in patients with FND and healthy controls showed levels of unemployment were very high in the FND group, at 41%.
  60. [60]
    Motor Conversion Disorder: A Prospective 2- to 5-Year Follow-Up ...
    At reassessment 2 to 5 years later, 19 patients had completely recovered and 8 patients had improved, whereas only 3 were unchanged or worse. Contrary to other ...Original Research Reports · Patients · Results<|control11|><|separator|>
  61. [61]
    Successful Treatment of Functional Neurologic Symptom Disorder ...
    Jul 24, 2025 · Enhanced neuroplasticity may facilitate recovery from the psychological and neurological stressors present in FND, possibly leading to long- ...
  62. [62]
    FND Hope UK on Instagram: "Our newly updated MyFND app ...
    Aug 11, 2024 · Our newly updated MyFND app enables users to log moods & symptoms, note anything that's been on their mind, record self-management techniques, learn strategies ...Missing: monitoring | Show results with:monitoring
  63. [63]
    A scoping review of studies on dissociative and conversion ...
    Jun 11, 2025 · Psychiatric comorbidities were the third most prevalent clinical features, specifically depression, anxiety, obsessive-compulsive disorder, and ...
  64. [64]
    Conversion Disorder Facts & Statistics - The Recovery Village
    Aug 30, 2024 · Lifetime prevalence rates of conversion disorder are between11–300 per 100,000 people · 5–14%of general hospital patients are diagnosed with ...
  65. [65]
    Incidence and prevalence of functional neurological disorder
    The incidence of FND was estimated at 10–22/100 000, while minimum prevalence of FND was estimated at 80–140/100 000, with a possible range of 50–1600/100 000.
  66. [66]
    Conversion Disorders: Background, Pathophysiology, Epidemiology
    Jul 20, 2021 · In behavioral models, conversion symptoms are viewed as a learned maladaptive behavior that is reinforced by the environment. The idea that ...Background · Pathophysiology · Epidemiology · PrognosisMissing: patterns | Show results with:patterns
  67. [67]
    Trial By Error: Does Functional Neurology Disorder Account for a ...
    Jun 16, 2022 · FND experts have a tendency to cite a higher figure—16%–as the prevalence among outpatient neurology consultations. Here, for example, is a ...
  68. [68]
    Increased Incidence of Functional (Psychogenic) Movement ... - NIH
    Among 550 new patients referred for evaluation at our tertiary care movement disorders centers, 45 (8.2%) received a diagnosis of FMD; 75.6% were female, in ...
  69. [69]
    Increased Incidence of Functional (Psychogenic) Movement ...
    Among 550 new patients referred for evaluation at our tertiary care movement disorders centers, 45 (8.2%) received a diagnosis of FMD; 75.6% were female, in ...
  70. [70]
    Disentangling Stigma from Functional Neurological Disorders - NIH
    Mar 29, 2017 · With this report, we aim to provide a roadmap for reducing stigma and improving care for functional neurological disorders (FND).Missing: underreporting | Show results with:underreporting
  71. [71]
    Stigma in functional seizures: A scoping review - ScienceDirect.com
    Our scoping review suggests that FS stigma is prevalent but remains understudied. We need more research with a specific focus on stigma in FS.<|separator|>
  72. [72]
    Full article: A systematic review of functional neurological disorder in ...
    Jul 25, 2025 · Gender affirmation can lead to resolution of FND symptoms. Trans people appear to make up a considerable proportion of people with FND. FND ...Missing: Cochrane | Show results with:Cochrane
  73. [73]
    Functional neurological disorder is a feminist issue - PubMed Central
    There is a large amount of data suggesting that FND affects more women than men. Current estimates tend towards a female to male sex ratio of 2–3:1.10 Estimates ...
  74. [74]
    Conversion disorder: the modern hysteria | Advances in Psychiatric ...
    Jan 2, 2018 · Reference Stephansson, Messina and MeyerowitzStephansson et al(1976) estimated the annual incidence to be about 22 cases per 100 000. Other ...Missing: relapse | Show results with:relapse
  75. [75]
    Conversion Disorder (300.11) | Abnormal Psychology
    Conversion Disorder appears in adolescence or early adulthood. Presentation before the age of 10 or after the age of 35 is rare, though some cases have been ...
  76. [76]
    Conversion disorder - Wikipedia
    Conversion disorder (CD) was a formerly diagnosed psychiatric disorder characterized by abnormal sensory experiences and movement problems
  77. [77]
    Zār Spirit Possession in Iran and African Countries: Group Distress ...
    Zār is the term used to describe a form of spirit possession common in northern African, eastern African, and some Middle-Eastern societies.
  78. [78]
    (PDF) Conversion disorders in Zulu patients - ResearchGate
    Aug 5, 2025 · Cultural and psychiatric aspects of conversion disorders in Zulu patients are surveyed. Some cross-cultural comparisons are made and ...
  79. [79]
    Culture and conversion disorder: implications for DSM-5 - PubMed
    Cross-culturally, conversion disorder is associated strongly with both dissociative and somatoform presentations, revealing no clear basis on which to locate ...Missing: variations | Show results with:variations
  80. [80]
    A scoping review of studies on dissociative and conversion...
    This scoping review synthesizes literature on dissociative and conversion disorders in India, focusing on their sociodemographic and clinical features, ...Etiological Factors · Clinical Features · Comorbid Psychiatric...<|control11|><|separator|>
  81. [81]
    [PDF] Socio-demographic factors and pattern of stressor in patients with ...
    Apr 15, 2023 · In India, the occurrence of conversion disorder is particularly high in young adults from poor socio-economic backgrounds, joint families, and ...
  82. [82]
    Women And Hysteria In The History Of Mental Health - PMC
    Hysteria is undoubtedly the first mental disorder attributable to women, accurately described in the second millennium BC, and until Freud considered an ...
  83. [83]
    Jean-Martin Charcot: Pioneer of Neurology | Cureus
    Aug 14, 2024 · At the Salpêtrière Hospital in Paris, Charcot noted the symptoms of hysteria. ... epilepsy," where he distinguished hysterical seizures ...
  84. [84]
    The life and work of Jean-Martin Charcot (1825–1893) - NIH
    His experiments in hypnosis and clinical demonstrations were open to the public. These 'hysteria shows' aroused the curiosity of the intellectuals and ...Missing: distinction | Show results with:distinction
  85. [85]
    Talking Cure Models: A Framework of Analysis - PMC
    Sep 13, 2017 · In therapeutic contexts, the catharsis concept was introduced by Breuer and Freud in their Studies on Hysteria (Breuer and Freud, 1895/2001).
  86. [86]
    Studies on Hysteria - an overview | ScienceDirect Topics
    Josef Breuer, a medical colleague of Freud, claimed to have relieved the hysterical symptoms of a female patient ('Anna O.') by such means. In Studies on ...
  87. [87]
    Shell shock: Psychogenic gait and other movement disorders ... - NIH
    Historical archives suggest that over 80,000 British soldiers suffered from “shell shock” as a direct result of combat exposure. Soldiers reported not only ...
  88. [88]
    [PDF] Chapter 15 War Psychiatry Conversion Disorders
    Conversion symptoms included mutism and stammering, deafness, gross tremor and other in- voluntary movements, paralysis and anesthesia, abnormal postures and ...Missing: possession | Show results with:possession<|separator|>
  89. [89]
    The classification of conversion disorder (functional neurologic ...
    In formal diagnostic classifications, “conversion disorder” was first known by that exact term in DSM-III (published in 1980: American Psychiatric Association, ...
  90. [90]