Somatic symptom disorders and functional neurological disorders

Authors

Caroline Dance* MD, FRCPC (biography and disclosures), Laila Drabkin* MD, FRCPC (biography and disclosures), Andrew Howard MD, FRCPC (biography, no disclosures) and Joseph Tham MD (biography, no disclosures)

^{*Caroline Dance and Laila Drabkin share first authorship.}

Dr. Caroline Dance disclosures: has received funding from the 2022 UBC CPD/CME Resident Research Grant. The grant/research support did not affect our choices when developing content.

Dr. Laila Drabkin disclosures: has received funding from the 2022 UBC CPD/CME Resident Research Grant. The grant/research support did not affect our choices when developing content.

What frequently asked questions/gaps we have noticed

Somatic symptom disorder and functional neurological disorder symptoms (formerly referred to as somatoform symptoms and conversion disorder symptoms) arise when individuals experience involuntary physical manifestations of emotional distress or emotional avoidance (precipitating fear or avoidance of specific emotional states). These physical manifestations present heterogeneously and their presentations have been recognized for over a century as psychosomatic. Together they span non-neurological (i.e. pain, GI disturbance, headache) and neurological (i.e. paralysis, seizure, cognitive dysfunction) symptom domains. These symptoms vary in severity and can have important functional implications for patients, with somatic symptom disorder and functional neurological disorder, by definition, causing significant clinical distress or disruption of daily life.¹

Somatic symptom disorder and functional neurological disorder symptoms are common in general practice and can present unique challenges in care planning.^2,3 Somatization is involuntary and in these conditions, the pathogenic mechanism involves patients being unaware of the underlying emotional cause of their physical symptoms. This lack of awareness—combined with a high degree of emotional and physical suffering—may understandably lead patients and care providers down a path where emotional distress goes unrecognized and untreated, while physical symptoms are treated unnecessarily.⁴ Although well-intentioned, this path can lead to iatrogenic harm and minimal symptomatic improvement for patients, as well as feelings of helplessness and moral distress for care providers.

Further, when considering somatic symptom disorder and functional neurological disorder symptoms and conditions, clinicians often describe difficulties such as: uncertainty, fear of breaking patient trust, fear of misdiagnosis, not wanting to offend and lack of consensus or guidelines on assessment and treatment.⁵ These challenges may lead to avoidance of encounters and of providing a diagnosis, as well as contribute to stigma surrounding these conditions.

This article aims to provide a structured approach to somatic symptom disorder and functional neurological disorder presentations, with the hope of supporting clinical care, reducing stigma and improving clinician confidence.

Data that answers these questions/gaps

Somatization is the body’s expression of emotional distress. We all experience somatization—it is a rapid and involuntary process.

• Somatization is often a normal and developmentally appropriate reaction to overwhelming emotional distress. Additional capacity to recognize and regulate distressing emotions may only develop over time. However, for a variety of reasons, including individual, attachment, social and environmental factors, some may experience barriers to developing these capacities.^6,7 This may lead, at times, to extremes of somatization that present clinically and impact daily function.

Somatic symptom disorder and functional neurological disorder symptoms are common across the lifespan.

• In youth, common presentations include headache, abdominal pain, pain in general and fatigue.^8,9
• In older adults, common presentations include pain (back, joint, arm or leg pain).¹⁰

Somatic symptom disorder and functional neurological disorder symptoms often do not fit predictable patterns seen with other illness pathology.

• These symptoms are based on an individual’s familiarity and understanding of body physiology (expectations of disability, illness and injury).
• Symptoms can be partially modelled on a co-occurring illness from which the individual suffers (e.g. development of non-epileptic seizures in an individual who also has epilepsy).

Secondary physical phenomena can develop in association with somatic symptom disorder and functional neurological disorder symptoms.

• For example, atypical use of a leg due to somatic symptom disorder or functional neurological disorder can result in limping, which can lead to objective musculoskeletal signs in the affected or other limb. Prolonged immobilization can cause significant disturbances in physiology and secondary symptoms or conditions, such as postural orthostatic tachycardia syndrome, complex regional pain syndrome, etc.

There are two Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnoses associated with somatic symptom disorder and functional neurological disorder symptoms. 

• Somatic symptom disorder (SSD): one or more somatic (i.e. non-neurological) symptoms that are distressing or result in the disruption of daily function, accompanied by excessive thoughts, feelings or behaviours related to the somatic symptom(s).
• Functional neurological disorder (FND): one or more symptoms of altered motor or sensory function that impact daily function and are not compatible with a known neurological condition.

SSD and FND are more similar than they are different, and are commonly comorbid.

• In both conditions, symptoms are involuntary and individuals are unaware of motivation.
• Although neurological (as in FND) and non-neurological (as in SSD) symptoms are categorized separately within the DSM-5, these conditions can be understood and approached similarly, and respond to similar interventions.
• It is the underlying psychological or psychiatric cause of SSDs/FNDs that best informs prognosis and treatment planning, not the specific physical symptoms with which an individual presents, or their chronicity (although this remains important).

SSD and FND are different than…

• Factitious disorder: voluntary production of symptoms, while unaware of motivation (which may include obtaining incentives or care through illness).
• Malingering (not a primary DSM-5 mental health diagnosis, but can be listed as a V-code as a potential focus of attention): voluntary production of symptoms, while aware of motivation for external gain.
• Illness anxiety disorder: preoccupation with acquiring a serious illness, but somatic symptoms are typically absent (and if present, are mild).

Seeking out secondary benefits and support should be expected and is not evidence of malingering. 

• Most clinicians would expect (and possibly encourage) an individual who has experienced a wrist fracture, or bowel complications from ulcerative colitis, for example, to establish whatever benefits they felt were necessary (e.g. additional support, time off work, insurance benefits).
• This ‘secondary benefit’ is the result of individuals doing the best they can to function with the supports that are available.

SSD and FND are independent risk factors for suicide.

• Feelings of hopelessness, including within the healthcare system¹¹, and the untreated underlying psychological and/or psychiatric condition, may contribute to increased suicidal ideation and self-harm.

It is important to consider the stigma that patients with SSD and FND might experience.¹²

• Patients with FND report experiences of stigma, including: blame for developing symptoms, the implication that they are feigning symptoms, abandonment by health care providers and social exclusion or rejection.
• Two factors which may positively impact patient experience and reduce stigma:
  • Feeling believed and accepted by health care professionals.
  • Feeling supported by a social network.

 Diagnosis is integral and can be therapeutic in itself. 

• After a thorough assessment, it is vital to clearly diagnose SSD and FND. Prompt diagnosis or shorter duration of symptoms is associated with better outcomes for patients.^13-17 For some patients, diagnosis will be the only therapeutic intervention needed to facilitate the resolution of symptoms.¹⁸

To understand the origin of symptoms and guide treatment, consider what ‘engine’ is driving somatization.⁴

• After arriving at a diagnosis, two primary causes of SSD and FND can be considered to help you and your patient understand the origin of their symptoms and guide treatment planning:
  • Psychological factors, such as history of trauma over the life span, losses, coping styles, personality traits, recent stressors and life changes etc.
  • Psychiatric conditions, such as major depressive disorder, generalized anxiety disorder, panic disorder, post-traumatic stress disorder, etc.
• Once the underlying cause(s) have been identified, a targeted treatment plan can be developed, guided by evidence-based treatment for the underlying psychiatric diagnosis and/or psychological factors.

What we recommend (practice tip)

1. Assess

Begin with the assumption that the presentation is not due to somatization.

• Complete a thorough initial assessment (may take place over multiple appointments), including a physical examination and medical investigations where indicated.
• Consider referral to a consultant specialist with expertise related to the presenting symptoms, where appropriate.

As you embark on work-up for the presenting symptoms, consider emotional contributors to symptoms early on in the assessment process. We recommend moving away from a duality where emotional states are considered only once physical contributors are ruled out. As you first start considering the relationship between emotional drivers and physical symptoms, it may be helpful to create a timeline of physical symptoms, psychological and social factors, and psychiatric symptoms.

It is important to note that due to the complexity and variability of symptoms, there are no questionnaires which are diagnostic for SSD/FND. Diagnosis of SSD/FND and identification of underlying psychiatric and psychological drivers requires a thorough and often longitudinal approach to assessment.

As you identify that your patient meets the criteria for a diagnosis of SSD/FND, it will be important to explore what psychological factors and/or psychiatric conditions are driving the condition (as above). Identification of these drivers is vital to help you and your patient understand their condition, and will guide the development of a patient-centred care plan.

2. Prepare

Review your findings and arrange for an appointment to share these with your patient, involving family or other supports where appropriate, with consent. Ensure there is adequate time, space and a quiet environment.

3. Meet

Summarize the patient’s course of illness and symptoms.

Describe the steps you have taken to first consider non-psychiatric causes of their illness.

Validate your patient’s experience, including the severity of their condition and suffering.

Clearly identify the symptoms as related to abnormal nervous system function (referred to as SSD or FND) and provide education about the prevalence, universality and scientific plausibility of somatization.

• “Somatization is the body’s expression/communication of emotional distress.”
• “A diagnosis of [SSD/FND] is serious and functionally impairing, and these symptoms are having a large impact on your life.”
• “Thankfully, there is often treatment for this condition. With treatment, symptoms can often improve and remit. On the other hand, delay in treatment can make symptoms more difficult to reverse.”
• Consider the use of a metaphor to help explain the process of somatization, such as hardware versus software:
  • “Imagine older apps not working like they used to on a new phone—the phone is physically intact, but the software isn’t functioning as smoothly as it did before.”
• Reassure your patient: “If new or sinister symptoms emerge, they will be reevaluated. However, further investigations are not needed at this time and, in fact, may delay care.”

4. Treat

Provide your patient with hope and guidance around the next steps.

Create a care plan that addresses the patient’s individual biological, psychological and social needs, with particular focus on psychological and psychiatric causes of their condition.

• A treatment plan might involve counselling, cognitive behavioral therapy (CBT), emotionally focused therapies and pharmacotherapy or neurostimulation for identified underlying psychiatric disorders. For patients with impairing or persisting symptoms, next steps often include referral to a general psychiatrist.
• Consider a holistic approach, including connection to allied health providers such as psychologists, counsellors, physical and occupational therapists, social workers and other health care clinicians. They may assist with physical functioning, support exposure to avoided activities and promote emotional expression. While access to these services can be challenging, persistence in seeking them out can be worthwhile.

Reassure your patient that you will continue to support them throughout the process, and that you will remain vigilant for any new and disabling symptoms. Emphasize that any new concerns will be thoroughly evaluated and not automatically attributed to somatization. Encourage the patient to reflect on their emotional environment when symptoms worsen, and work together to establish a clear plan for follow-up.

5. Revisit

If sinister or new symptoms emerge, undertake appropriate investigations, including consideration of re-evaluation by a consultant specialist.

Summary

This article highlights the importance of a thorough assessment that considers both physical and psychological factors—working to understand why the patient is suffering emotionally at that moment in time, and why it is presenting physically. It is vital to validate emotional and physical suffering, and emphasize that somatization is a form of involuntary (i.e. not intentionally produced) response to emotional distress. Clinicians are encouraged to diagnose SSD/FND promptly, as timely identification can improve outcomes. Holistic treatment is encouraged, incorporating psychological therapies, psychiatric care and support for physical symptoms, while reducing stigma and enhancing patient-provider alliance. The clinician should maintain a longitudinal perspective that incorporates patient-centred assessment, thoughtful explanations and treatment phases towards recovery.

Resources

• Understanding and Managing Somatoform Disorders (Dr. Scamvougeras and Dr. Howard, 2018)
• Somatic Symptom Disorder and Functional Neurological Disorder Online Course (UBC CPD)
• Online FND Guide (Dr. Jon Stone)

Handouts for patients

• Somatoform Brochure (British Columbia Neuropsychiatry Program)

References

1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text rev. American Psychiatric Association; 2022. (View with UBC)
2. Lehmann M, Pohontsch NJ, Zimmermann T, Scherer M, Löwe B. Estimated frequency of somatic symptom disorder in general practice: cross-sectional survey with general practitioners. BMC Psychiatry. 2022;22(1):632. doi:10.1186/s12888-022-04100-0 (View)
3. de Waal MW, Arnold IA, Eekhof JA, van Hemert AM. Somatoform disorders in general practice: prevalence, functional impairment and comorbidity with anxiety and depressive disorders. Br J Psychiatry. 2004;184:470-476. doi:10.1192/bjp.184.6.470 (View)
4. Scamvougeras A, Howard A. Understanding and Managing Somatoform Disorders: A Guide for Clinicians. AJKS Medical; 2018. (View with UBC)
5. Barnett C, Davis R, Mitchell C, Tyson S. The vicious cycle of functional neurological disorders: a synthesis of healthcare professionals’ views on working with patients with functional neurological disorder. Disabil Rehabil. 2022;44(10):1802-1811. doi:10.1080/09638288.2020.1822935 (View with UBC)
6. Beck JE. A developmental perspective on functional somatic symptoms. J Pediatr Psychol. 2008;33(5):547-562. doi:10.1093/jpepsy/jsm113 (View with UBC)
7. Okur Güney ZE, Sattel H, Witthöft M, Henningsen P. Emotion regulation in patients with somatic symptom and related disorders: a systematic review. PLoS One. 2019;14(6):e0217277. doi:10.1371/journal.pone.0217277 (View)
8. Boerner KE, Dhariwal AK, Chapman A, Oberlander TF. When feelings hurt: Learning how to talk with families about the role of emotions in physical symptoms. Paediatr Child Health. 2022;28(1):3-7. Published 2022 Jul 5. doi:10.1093/pch/pxac052 (View)
9. Malas N, Ortiz-Aguayo R, Giles L, Ibeziako P. Pediatric somatic symptom disorders. Curr Psychiatry Rep. 2017;19(2):11. doi:10.1007/s11920-017-0760-3 (View with UBC)
10. Dehoust MC, Schulz H, Härter M, et al. Prevalence and correlates of somatoform disorders in the elderly: results of a European study. Int J Methods Psychiatr Res. 2017;26(1):e1550. doi:10.1002/mpr.1550 (View)
11. Torres ME, Löwe B, Schmitz S, Pienta JN, Van Der Feltz-Cornelis C, Fiedorowicz JG. Suicide and suicidality in somatic symptom and related disorders: a systematic review. J Psychosom Res. 2021;140:110290. doi:10.1016/j.jpsychores.2020.110290 (View)
12. Foley C, Kirkby A, Eccles FJR. A meta-ethnographic synthesis of the experiences of stigma amongst people with functional neurological disorder [published correction appears in Disabil Rehabil. 2023 Mar;45(6):1114]. Disabil Rehabil. 2024;46(1):1-12. doi:10.1080/09638288.2022.2155714 (View or View correction)
13. Asadi-Pooya AA, Bahrami Z, Homayoun M. Natural history of patients with psychogenic nonepileptic seizures. Seizure. 2019;66:22-25. doi:10.1016/j.seizure.2019.02.006 (View)
14. Feinstein A, Stergiopoulos V, Fine J, Lang AE. Psychiatric outcome in patients with a psychogenic movement disorder: a prospective study. Neuropsychiatry Neuropsychol Behav Neurol. 2001;14(3):169-176. (View with UBC)
15. Gelauff J, Stone J, Edwards M, Carson A. The prognosis of functional (psychogenic) motor symptoms: a systematic review. J Neurol Neurosurg Psychiatry. 2014;85(2):220-226. doi:10.1136/jnnp-2013-305321 (View with UBC)
16. Couprie W, Wijdicks EF, Rooijmans HG, van Gijn J. Outcome in conversion disorder: a follow up study. J Neurol Neurosurg Psychiatry. 1995;58(6):750-752. doi:10.1136/jnnp.58.6.750 (View)
17. Farias ST, Thieman C, Alsaadi TM. Psychogenic nonepileptic seizures: acute change in event frequency after presentation of the diagnosis. Epilepsy Behav. 2003;4(4):424-429. doi:10.1016/s1525-5050(03)00143-4  (View with UBC)
18. Henningsen P. Management of somatic symptom disorder. Dialogues Clin Neurosci. 2018;20(1):23-31. doi:10.31887/DCNS.2018.20.1/phenningsen (View)

Editor’s note

Sept. 2, 2025

Comments since publication of this article identify concerns that some diseases may be prematurely categorized as psychosomatic based on lack of knowledge, bias or emerging knowledge development. This article can’t properly address all of these in the context of this article, but rather highlight that clinicians be aware of the potential, and hazards, of early diagnostic closure in certain diseases and re-emphasize the authors’ first recommendation, to begin with the assumption that the presentation is not due to somatization in the assessment phase.

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