Psychiatric Comorbidities in Functional Movement Disorders: A Retrospective Cohort Study

ABSTRACT

Background

Functional movement disorders (FMD) are characterized by abnormal movements and motor symptoms incongruent with a known structural neurologic cause. While psychological stressors have long been considered an important risk factor for developing FMD, little is known about the impact of psychiatric comorbidities on disease manifestations or complexity.

Objectives

To compare characteristics of FMD patients with co‐occurring mood and trauma‐related psychiatric conditions to FMD patients without psychiatric conditions.

Methods

We performed a retrospective cohort study of patients seen in the University of Colorado Health system between January 1, 2015 and December 31, 2019. Patients were included if they had a diagnosis of FMD, determined by ICD‐10 coding and ≥1 phenomenology‐related diagnostic code (tremor, gait disturbances, ataxia, spasms, and weakness), and at least one encounter with a neurology specialist. Fisher's exact and unpaired t‐tests were used to compare demographics, healthcare utilization, and phenomenologies of patients with psychiatric conditions to those with none.

Results

Our review identified 551 patients with a diagnosis of FMD who met inclusion criteria. Patients with psychiatric conditions (N = 417, 75.7%) had increased five‐year healthcare utilization (mean emergency room encounters 9.9 vs. 3.5, P = 0.0001) and more prevalent non‐epileptic seizures (18.2% vs. 7.5%, P = 0.001). Suicidal ideation (8.4%) and self‐harm (4.1%) were only observed amongst patients with comorbid psychiatric conditions.

Conclusions

Patients with FMD and comorbid psychiatric conditions require more healthcare resources and have greater disease complexity than patients without psychiatric illness. This may have implications for treatment of patients without comorbid psychiatric conditions who may benefit from targeted physiotherapy alone.

Functional movement disorders (FMD) are characterized by abnormal movements not explained by a structural neurologic disorder and are often grouped with other conditions such as non‐epileptic seizures (NES) and dissociative amnesia under the broader umbrella of functional neurological disorders. FMD can present with a variety of movement phenomenologies, including tremors, spasms, limb weakness, myoclonus, dyskinesias, and gait disturbances. ¹ Clinical findings which help distinguish FMD from structural movement disorders include entertainability, coactivation, variability, and distractibility. ² , ³ The pathophysiology of FMD is poorly understood, but is thought to be due to an impairment of self‐agency where a presumed “voluntary” movement is perceived as involuntary. ¹ , ⁴ , ⁵ FMD is associated with significant disability comparable to other neurologic conditions, like Parkinson's disease and multiple sclerosis. ⁶ The presence of multiple symptom manifestations and phenomenologies is also thought to reflect overall disorder severity. ⁷ Treatment is complex and ideally provided by a multidisciplinary approach involving neurologists, psychiatrists, psychologists, physical therapists, and occupational therapists, with early diagnosis and initiation of appropriate treatment predicting positive outcomes. ⁸

FMD, and functional neurological disorders more broadly, are considered synonymous with “dissociative”, “conversion”, or “psychogenic” disorders; however, there has been a recent shift towards using the term “functional”, which emphasizes the proposed underlying mechanism and avoids connotations associated with terms like “psychogenic”, which carry myopic and dualistic etiological assumptions. ⁹ , ¹⁰ While patients with FMD have higher rates of depression and anxiety disorders compared to healthy adults and those with other movement disorders, psychiatric conditions are neither necessary nor sufficient for the development of FMD. ¹¹ , ¹² It is well recognized that the presence of psychiatric comorbidities is associated with greater disability and worse outcomes in other neurological conditions. ¹³ While the prevalence of FMD continues to grow and account for up to 10% of all referrals to movement disorder specialists, ¹⁴ there are few large observational studies which compare patients with and without psychiatric conditions while examining the synergistic effects of comorbid mental illness on disease complexity.

The aim of this paper is to compare the characteristics of FMD patients with co‐occurring mood and trauma‐related psychiatric conditions (e.g. post‐traumatic stress disorder) to patients without psychiatric conditions. We hypothesize that FMD patients with psychiatric comorbidities have more complex disease defined by greater healthcare utilization, the presence of more than one type of movement or motor phenomenology, and/or more concurrent non‐motor functional neurological disorders.

Methods

We conducted a retrospective study of FMD patients treated in a large, academic referral center. The University of Colorado (CU) Health Data Compass (Compass) platform is a multi‐institutional data warehouse funded by UCHealth, Children's Hospital Colorado, CU Medicine, and the CU School of Medicine and is administratively housed in the Colorado Center for Personalized Medicine. Compass allows researchers access to limited, de‐identified data sets for research purposes and to improve health outcomes. The data warehouse contains inpatient and outpatient electronic medical record (EMR) data including demographics, encounters, diagnoses, procedures, medications, and laboratory results extracted from state‐level all‐payers claims data, two EMR systems, and the state of Colorado death registry. Using cloud‐based, non‐relational database architectures, Compass creates unique datasets organized for data analytics. Patient data is integrated into the Compass enterprise data warehouse through processes which extract data from various source systems, transform that data into a common schema (Observational Medical Outcomes Partnership Common Data Model V5.3), and load the data into the data warehouse. Integration and linkage of disparate data sources creates a comprehensive, de‐identified, longitudinal patient record. Relevant administrative and clinical data is then extracted into data marts that may also merge external data sources to support research analytics. The Compass data warehouse is fully hosted on the Google Cloud Platform (GCP) and uses a wide range of “Big Data” tools provided in GCP, including Google BigQuery, Cloud Storage, Compute Engine, Stackdriver, Cloud Genomics, and DataLab for large‐scale analytics. Leveraging Google's extensive security framework and certifications, Compass has achieved National Institute of Standards and Technology (NIST) 800–53 compliance with external third‐party validation. The Compass Informatics environment has been certified as Health Insurance Portability and Accountability Act (HIPAA) compliant.

This study was exempt from Institutional Review Board (IRB) approval given the de‐identified nature of the dataset and the adherence to HIPAA security and compliance standards on the part of the Compass platform.

Study Setting and Data Query

All patients included in the de‐identified dataset received care through the UCHealth medical system. Queried medical encounters occurred between January 1, 2015 and December 31, 2019. FMD cases included all adult patients age 18 years or older with an inclusion diagnosis of “Conversion disorder with motor symptom or deficit” (ICD‐10‐CM: F44.4), “Conversion disorder with mixed symptom or deficit” (ICD‐10 code F44.7), “Other dissociative and conversion disorders” (ICD‐10 code F44.8), or “Conversion disorder” (ICD‐10 code F44 or ICD‐9 code 300.11). The use of these diagnostic codes for describing functional neurological disorders is an accepted strategy for defining functional neurological disorders and has been used previously in the literature. ¹⁵ , ¹⁶

As there is currently no specific diagnostic code for “functional movement disorder,” only patients with at least one neurology specialist encounter and at least one ICD‐10 code related to pre‐specified movement and motor phenomenologies were included in the analysis. Phenomenology‐related diagnostic codes for motor and movement phenomenology included weakness (ICD‐10 codes R53.1 & R53.2), gait disturbances (ICD‐10 code R26*), tremor (ICD‐10 code 25.1), spasms (ICD‐10 code R25.2) and ataxia (ICD‐10 codes R26.0 & R27.0). To increase the likelihood of diagnostic accuracy, we analyzed a subgroup of patients who had a neurology specialty encounter linked with one or more inclusion ICD‐10 diagnostic codes, looking for consistency of findings with the larger cohort.

Patients with mood and trauma‐related psychiatric comorbidities were identified by the occurrence of psychiatric diagnosis codes including depressive disorders (ICD‐10 codes F32* and F33*), anxiety disorders (ICD‐10 code F41*), trauma and stress related disorders such as post‐traumatic stress disorder (PTSD) (ICD‐10 codes F43*), and personality disorders (ICD‐10 code F60*).

Non‐motor functional neurological disorder conditions were tracked using diagnostic codes for conversion disorder related to non‐epileptic seizures (ICD‐10 code F44.5) and dissociative functional neurological disorder (ICD‐10 codes F44.0, F44.9, & F44.89).

Diagnostic codes for suicidal ideation (ICD‐10 code R45.851) and personal history of self‐harm (ICD‐10 codes Z91.5 & T14.91) were also tracked.

Statistical Analysis

Descriptive statistics were used to define the demographics, co‐occurrence of phenomenology‐related diagnostic codes, and frequencies of the pre‐specified psychiatric diagnoses, non‐motor functional neurological disorder diagnoses, and suicidality of our cohort. Two‐tailed Fisher exact tests and unpaired t‐tests were used to compare demographics, healthcare utilization rates, and frequencies co‐occurring diagnostic codes comparing patients with psychiatric illness to those without psychiatric illness‐related diagnostic codes. Microsoft Excel for Mac (Microsoft Office 2019, Version 16.46.21021202) was used to analyze data.

Results

Query of all patient encounters with inclusion diagnoses yielded an initial cohort of 1834 patients. A total of 551 patients met our conditions for a diagnosis of FMD and were included in the analysis. A full description of patient characteristics, phenomenology, and psychiatric comorbidities is summarized in Table 1. There were higher rates of females (69.7%), as has been described in other FMD studies, ¹⁷ the cohort was 77.0% white with an average age of 51.1 years (SD = 16.3). On average, patients saw an outpatient neurology specialist twice annually (SD = 2.5). The majority of patients had a single motor or movement phenomenology‐related diagnostic code (51.4%), with weakness (49.9%) and gait disturbances (49.0%) being the most common, while 48.6% had multiple phenomenology‐related diagnostic codes. A proportion of patients had co‐occurring diagnostic codes for non‐motor functional neurological disorders including non‐epileptic seizures or convulsions (15.6%) and dissociative amnesia (0.5%). (See Table 1).

TABLE 1.

Patient characteristics & five‐year prevalence of phenomenology‐related, non‐motor FND, and psychiatric diagnostic codes

Characteristics	N = 551No. (%)
No. female	384 (69.7%)
Mean age, years (SD)	51.1 (16.3)
Race
White	424 (77.0%)
Black	41 (7.4%)
Multiracial	19 (3.4%)
Asian	9 (1.6%)
Other	39 (7.1%)
Unknown	19 (3.%)
Ethnicity
Hispanic	54 (9.8%)
Non‐Hispanic	475 (86.2%)
Unknown	22 (4.0%)
Annual no. neurology outpatient visits (SD)	2.2 (2.5)
Co‐occurring phenomenology‐related diagnostic codes
Weakness	275 (49.9%)
Gait disturbance	270 (49.0%)
Tremor	204 (37.0%)
Ataxia	74 (13.4%)
Dystonia/Spasm	82 (14.9%)
Multiple phenomenology codes	268 (48.6%)
Co‐occurring non‐motor FND diagnostic codes
Non‐epileptic seizures	86 (15.6%)
Dissociative amnesia	3 (0.5%)
Co‐occurring psychiatric diagnostic codes	N = 417 (75.7%) No. (%)
Anxiety disorder	332 (60.3%)
Depressive disorder	271 (49.2%)
Post‐traumatic stress disorder	134 (24.3%)
Panic disorder	49 (8.9%)
Adjustment disorder	39 (7.1%)
Any personality disorder	15 (2.7%)
Dissociative identity disorder	2 (0.4%)

Abbreviations: FND, functional neurological disorder; SD, standard deviation.

The majority of patients (N = 417, 75.7%) had at least one co‐occurring diagnostic code of a mood disorder or trauma‐related psychiatric condition while 134 patients (24.3%) had none. A full description of the demographic and healthcare utilization differences between these two groups is presented in Table 2. Comparison of these groups reveals several differences: patients with psychiatric conditions were more likely to be female (73.9% vs. 56.7%, OR = 2.2), younger (mean age 50.3 vs. 54.0 years, P = 0.02), and had a higher 5‐year average number of healthcare encounters with greater prevalence of neurology outpatient encounters (P = 0.004), emergency room visits (P < 0.001), inpatient encounters (P < 0.001), and diagnostic testing including more laboratory (P < 0.001) and radiology billing encounters (P < 0.001).

TABLE 2.

Comparison of characteristics and five‐year healthcare utilization amongst motor FND patients with and without psychiatric comorbidities

N = 551	Psychiatric Comorbidities Present (N = 417, 75.7%)		Psychiatric Comorbidities Absent (N = 134, 24.3%)
Characteristics	No.	%	No.	%	P‐value	OR (95% CI)
No. female	308	73.9%	76**	56.7%	0.0002	2.2 (1.4–3.2)
Mean age, years (SD)	50.3 (15.8)	—	54.0* (17.6)	—	0.02 (−6.9 to −0.5)	—
Race
White	326	78.2%	98	73.1%	0.14	1.3 (0.8–2.1)
Black	31	7.4%	10	7.5%	0.56	1.0 (0.5–2.1)
Multiracial	15	3.6%	4	3.0%	0.49	1.2 (0.4–3.7)
Asian	5	1.2%	4	3.0%	0.15	0.4 (0.1–1.5)
Other	30	7.2%	9	6.7%	0.51	1.1 (0.5–2.3)
Unknown	10	2.4%	9*	6.7%	0.02	0.34 (0.1–0.9)
Ethnicity
Hispanic	41	9.8%	13	9.7%	0.56	1.0 (0.5–2.0)
Non‐Hispanic	364	87.3%	111	82.8%	0.12	1.4 (0.8–2.4)
Unknown	12	2.9%	10*	7.5%	0.02	0.4 (0.2–0.9)
Five Year Healthcare Utilization	Mean	SD	Mean	SD	P‐value
No. neurology outpatient encounters	12.1	13.1	8.6**	8.8	0.004	—
No. neurology hospital encounters	1.5	1.2	1.7	1.0	0.08	—
No. ER billing encounters	9.9	15.7	3.5**	3.2	0.0001	—
No. inpatient billing encounters	14.6	15.0	8.7**	8.2	0.0001	—
No. laboratory billing encounters	8.2	11.8	4.2**	5.3	0.0002	—
No. radiology billing encounters	23.2	26.6	10.6**	10.2	0.0001	—

^* P < 0.05.

^** P < 0.01.

Abbreviations: ER, emergency room; OR, odds ratio; SD, standard deviation.

Patients with psychiatric comorbidities were more likely to have multiple, co‐occurring phenomenology codes (50.6% vs. 41.0%, OR = 1.5), though the frequencies of individual phenomenology‐related diagnostic codes did not differ between these groups. In addition, patients with psychiatric conditions were more likely to have a diagnosis consistent with non‐epileptic seizures (OR = 2.8). Patients with psychiatric comorbidities also had a 5‐year prevalence of suicidal ideation of 8.4%, with no cases of suicidal ideation or self‐harm identified in those without psychiatric conditions (see Table 3).

TABLE 3.

Comparison of five‐year prevalence of co‐occurring diagnoses amongst functional movement disorder patients with and without psychiatric diagnoses

Diagnostic codes	Psychiatric Comorbidities Present (N = 417)		Psychiatric Comorbidities Absent (N = 134)
	No.	%	No.	%	P‐value	OR (95% CI)
Phenomenology‐related
Gait disturbance	203	48.7%	67	50.0%	0.43	0.9 (0.6–1.4)
Weakness	215	51.6%	60	44.8%	0.10	1.3 (0.9–1.9)
Ataxia	56	13.4%	18	13.4%	0.55	1.0 (0.6–1.8)
Tremor	154	27.9%	50	37.3%	0.51	1.0 (0.7–1.5)
Spasms	65	11.8%	17	12.3%	0.25	1.3 (0.7–2.3)
Multiple phenomenology‐related codes	211	50.6%	55*	41.0%	0.03	1.5 (1.0–2.2)
Non‐motor FND
Non‐epileptic seizures	76	18.2%	10**	7.5%	0.001	2.8 (1.4–5.5)
Dissociative amnesia	2	0.5%	1	0.7%	0.57	0.6 (0.1–7.1)
Suicidal ideation	35	8.4%	0***	0.0%	< 0.001	25.0 (1.5–409.8)
Self‐harm	17	4.1%	0*	0.0%	0.02	12.8 (0.8–215.7)

^* P < 0.05.

^** P < 0.01.

^*** P < 0.001.

Abbreviations: FND, functional neurological disorder; OR, odds ratio.

For our subgroup analysis, we identified 417 patients who had at least one neurology outpatient encounter directly linked with one or more conversion disorder ICD‐10 diagnostic codes (See Tables S1 and S2). Of these, 319 (76.5%) had a mood or trauma‐related psychiatric condition while 98 (23.5%) did not. We observed differences between these two groups including higher five‐year healthcare utilization and greater five‐year prevalence of non‐epileptic seizures (20.7% vs. 9.2%, OR = 2.6) amongst patients with FMD and comorbid psychiatric conditions. There were differences in the frequencies of multiple phenomenology codes; patients with psychiatric conditions were more likely to have co‐occurring movement phenomenologies (54.5% vs. 49.0%) although this did not reach the threshold of statistical significance.

Discussion

In this large, retrospective review we show that patients with FMD have high rates of comorbid psychiatric disease and that comorbid psychiatric conditions are associated with increased odds for healthcare utilization and disease complexity. Our cohort demonstrates a high frequency of comorbid psychiatric diagnoses with three quarters of patients carrying a diagnosis of at least one mood disorder or post‐traumatic stress disorder, consistent with previous observational studies. ¹⁸ Amongst patients with FMD and comorbid psychiatric disease, over two‐thirds had an anxiety disorder, nearly a third had a diagnosis of depression, and a third had a trauma‐related disorder (e.g. PTSD), corroborating previous findings from observational studies with smaller cohorts. ¹⁶ , ¹⁹ , ²⁰ , ²¹ , ²² We identified key differences between patients with and without comorbid psychiatric disease: patients with psychiatric comorbidities were more likely to have suicidal ideation or self‐harm and had nearly twice as many emergency department encounters over 5 years. These findings substantiate preliminary findings in the literature while presenting new findings about the interplay between psychiatric conditions and FMD. ²³ , ²⁴ Along these lines, ours is the largest FMD study to describe patients without psychiatric conditions, generating many questions for future research including the effect of patients' perceptions of disease and patient characteristics which predict disease and complexity with implications for targeted treatment and future interventions.

In our cohort, 24.3% had no co‐occurring psychiatric diagnosis codes for mood disorders or trauma‐related psychiatric conditions. This group differed from those with psychiatric conditions by gender and age further emphasizing this group as unique from those experiencing concurrent mental illness and may have relevant implications for future interventions. While psychiatric care has traditionally been the mainstay for treatment of FMD, there is preliminary evidence to suggest that physiotherapy without mental health care may be an effective strategy for managing the disorder for those with isolated FMD. ²⁵ This subset of patients may benefit from a more targeted approach that is focused on motor symptoms rather than addressing non‐contributory mood or trauma‐related issues. This has already proven feasible and possibly effective for FMD in the absence of comorbid depression or anxiety, with one randomized clinical trial of physiotherapy demonstrating the acceptability of this approach and preliminary data suggesting a large treatment effect and cost benefit. ²⁵

Several studies have explored a variety of management strategies for FMD with growing evidence for the use of physical therapy, cognitive behaivoral therapy, psychotherapy, medical management, and interdiscplinary care. ²⁶ , ²⁷ , ²⁸ , ²⁹ , ³⁰ Of these, physical therapy, in the form of motor reprogramming, shows great promise for FMD patients, both with and without psychiatric comorbidities, and has the potential to improve both movement and mood symptoms. ²⁵ , ³¹ , ³² , ³³ Conversely, monotherapy with psychotherapy alone may be insufficient for managing FMD, with one study of psychodynamic psychotherapy for a small cohort of FMD patients with comorbid psychiatric conditions showing no significant improvements in psychiatric nor motor symptoms. ³⁰ To this end, our findings highlight the heterogeneity within this patient population which may warrant targetd treatment approaches for FMD rather than a “one size fits all” approach. Treatment of FMD patients without psychiatric comorbidities has yet to be fully defined and these key differences amongst patients may inform future clincial trial and intervention design.

We observed similar rates of suicidal ideation to those observed across all patients receiving outpatient neurology care as reported in the literature (8.4% in our cohort vs. 9%) and similar rates of self‐harm described in the context of FND. ²³ , ³⁴ One study by Güleç et al. describing 96 patients with conversion disorder showed that alcohol abuse, increased healthcare utilization and dissociative symptoms were predictive of suicide attempts. ²³ Our findings suggest that comorbid psychiatric illness in FMD plays a role, given we observed no instances of suicidal ideation or self‐harm in patients without mood disorders or PTSD. Suicidal behavior is a complex and multifactorial issue with psychiatric illness, especially depression, being major risk factors. ³⁵ However, neurologic illness and functional limitations due to physical illness can also confer a risk of suicide. ³⁶ , ³⁷ , ³⁸ , ³⁹ While we cannot rule out the possibility that the between‐group differences were influenced by coding errors or differences in clinician coding style, our observations of those without psychiatric illness at least suggest that these patients may not be experiencing disorder complexity conferring an increased risk of suicidality.

While the retrospective design of our study allowed for a large and diverse patient group, it is also a relevant limitation given our reliance on diagnostic coding to establish a case of FMD. Use of ICD codes to establish a diagnosis is common to the emerging study of large, retrospective datasets. There is evidence to suggest that there is good concordance between ICD coding and clinical diagnosis in other neurologic conditions, like stroke. ⁴⁰ More specifically, the use of diagnostic coding for this purpose has been used in previous FMD research, ¹⁵ , ¹⁶ , ⁴¹ while also being an accepted strategy for analyzing big datasets of non‐neurological diagnoses. ⁴² , ⁴³ We attempted to counter the issue of diagnostic accuracy by including only patients with at least one neurology encounter and by examining a subgroup of patients who had a diagnosis of ICD‐10 F44‐related diagnosis code expressly associated with an outpatient neurology evaluation. This ensured that patients at least received a formal neurologic evaluation by a board‐certified neurologist. The subgroup analysis showed comparable between‐group similarities and differences to those in the larger cohort. Phenomenology‐related diagnostic codes carry their own limitations and there is the possibility of incomplete symptom capture with underreporting of disease complexity. While the co‐occurrence of these codes with the conversion disorder inclusion codes (F44*) is highly suggestive of their association, we cannot definitively conclude that these symptoms are explicitly due to FMD or are alternatively explained by another neurologic or medical conditions. Along these lines, the high prevalence of gait disturbances in our cohort may reflect an alternative phenomenology whereby the gait abnormality may be due to ataxia, spasms, or weakness. We also cannot rule out that the differences observed in healthcare utilization were related to mental health care as we did not capture encounters associated with psychiatric specialty services. This is an important consideration for future research given that patients with psychiatric illness are at higher overall risk for developing chronic medical comorbidities and this may be reflected in our dataset. ⁴⁴ However, we are more confident in our observation that patients with psychiatric illness had greater utilization of outpatient neurologic specialty services.

Despite these limitations, our cohort reproduces many findings previously demonstrated in the literature while providing new insights into FMD and psychiatric disease, especially for those patients without mood disorders or trauma‐related mental illness. ¹⁵ Our study suggests that people with FMD and comorbid psychiatric conditions have greater disorder complexity, with more complex disease phenomenology and greater healthcare utilization. Future studies should examine whether mood disorders like depression and anxiety disorders are manifestations of FMD or if a causal relationship between psychiatric conditions and FMD disease burden exists. Future prospective studies are needed to describe these relationships and continue to explore the ways that past emotional or physical trauma influence the disorder. Interventional studies, especially those related to motor reprogramming, should explore whether mental health evaluation and treatment is a necessary prerequsite to physical therapy programs, especially for individuals who have no preexisting or concurrent psychaitric conditions or past trauma. Detection of coexisting psychiatric and post‐traumatic psychiatric conditions in the setting of FMD may serve to stratify treatment options and aid in the development of personalized models of neuropsychologic care and rehabilitation.

Author Roles

(1) Research Project: A. Conception, B. Organization, C. Execution; (2) Statistical Analysis: A. Design, B. Execution, C. Review and Critique; (3) Manuscript Preparation: A. Writing of the First Draft, B. Review and Critique.

Z.A.M.: 1B, 1C, 2A, 2B, 2C, 3A, 3B

I.K.: 1C, 2C, 3B

C.O.: 2C, 3B

S.K.M.: 1A, 1B, 1C, 2C, 3B

Disclosures

Ethical Compliance Statement

This study was exempt from Institutional Review Board (IRB) approval as it utilized a de‐identified dataset provided by the Compass data platform which adheres to the HIPAA security and compliance standards of its partners. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines.

Funding Sources and Conflicts of Interest

Study funding provided by the National Institute on Aging's (NIA) Multidisciplinary Research Training in Palliative Care and Aging award number T32AG044296. The authors declare there are no conflicts of interest relevant to this work.

Financial Disclosures for the Previous 12 Months

The authors declare that there are no additional disclosures to report.

Supporting information

Table S1. Subgroup analysis of functional movement disorder patients with a neurology encounter specifically linked to an ICD‐10 inclusion diagnosis code.

Table S2. Subgroup analysis of five‐year prevalence of co‐occurring diagnostic codes for functional movement disorder patients with a neurology encounter specifically linked to an ICD‐10 inclusion diagnosis code.