Where are somatoform disorders going? An update on the DSM-V

Keywords::

• conversion disorder
• DSM-IV
• malingering
• PNES
• pseudoseizures
• psychogenic nonepileptic events
• psychogenic nonepileptic seizures
• psychogenic seizures
• somatization
• somatoform disorders

Why include an update on the DSM in a neurology journal on epilepsy?

Psychogenic nonepileptic events (PNEE) are commonly seen at epilepsy centers, where they represent at least 30% of patients referred for refractory seizures [1]. The literature on PNEE often implies that they represent a unique disorder. In reality, PNEE are but one type of somatoform disorder. How the psychopathology is expressed (PNEE, paralysis, diarrhea or pain) is only different in the diagnostic aspects [2]. Fundamentally, the underlying psychopathology, its prognosis and its management, are no different for PNEE than they are for other psychogenic symptoms. Thus, PNEE represent an excellent and well-studied prototype of somatoform disorders. However uncomfortable they may be, neurologists and epileptologists will have to deal with this challenge, both in diagnosis and in management.

Psychogenic (nonorganic, ‘functional’) symptoms are common in medicine. Conservative estimates consider that at least 10% of all medical services are provided for psychogenic symptoms. Every medical specialty has its share of symptoms that can be of psychogenic origin. In gastroenterology, these include: vomiting, dysphagia, abdominal pain, and diarrhea. In cardiology, noncardiac chest pain is traditionally referred to as ‘musculoskeletal’ chest pain, but it is probably psychogenic. Symptoms that can be psychogenic in other specialties include shortness of breath and cough in pulmonary medicine, psychogenic globus or dysphonia in otolayngology, excoriations in dermatology, erectile dysfunction in urology, and blindness or convergence spasms in ophthalmology. Pain syndromes for which a psychogenic component is likely include tension headaches, chronic back pain, limb pain, rectal pain and sexual organ pain. Owing to the fact that pain, by definition, is entirely subjective, it is extremely difficult, and perhaps impossible, to confidently diagnose pain as ‘psychogenic.’ It could even be argued that all pains are psychogenic and thus psychogenic pain is one of the most ‘uncomfortable’ diagnoses to make. In addition to isolated symptoms, some syndromes are considered to be at least partly psychogenic by some, and possibly entirely psychogenic (i.e., without any organic basis) by others. These controversial but ‘fashionable’ diagnoses include fibromyalgia, fibrositis, myo-fascial pain, chronic fatigue, irritable bowel syndrome and multiple chemical sensitivity. Among psychogenic symptoms, PNEE are unique in one principal characteristic; with EEG-video monitoring, they can be diagnosed with near-certainty. This is in sharp contrast to other psychogenic symptoms, which are usually a diagnosis of exclusion.

However, even for PNEE, the most provable psychogenic symptom, the mental health profession is often skeptical and often does not believe the diagnosis [2,3]. In fact, the American Psychiatric Association and American Psychological Association (APAs) appear to show little interest in this category of disorders, as neither organization’s websites providing patient education materials include any information about this category of disorders [101,102].

Here we will discuss the old DSM-IV classifications and then discuss the upcoming changes in the DSM-V.

Psychopathology & the DSM-IV scheme

PNEE are by definition a psychiatric disorder. According to the DSM-IV classification [4], physical symptoms caused by psychological causes can fall under three categories: somatoform disorders, factitious disorders and malingering. By definition, somatoform disorders are the unconscious production of physical symptoms due to psychological factors, which means that symptoms are not under voluntary control, that is, the patient is not faking and not intentionally trying to deceive. Somatoform disorders are subdivided into several disorders depending on the characteristics of the physical symptoms and their time course. The two somatoform disorders relevant to PNEE are conversion disorder and somatization disorder. In fact, the DSM-IV has a subcategory of conversion disorder specifically termed conversion disorder with seizures. By contrast, to the unconscious (unintentional) production of symptoms of the somatoform disorders (including conversion), factitious disorder and malingering imply that the patient is purposely deceiving the physician, that is, faking the symptoms. The difference between the two (factitious disorder and malingering) is that in malingering the reason for doing so is tangible and rationally understandable (albeit possibly reprehensible), while in factitious disorder the motivation is a pathologic need for the sick role. An important corollary, therefore, is that malingering is not considered a mental illness whereas factitious disorder is [4].

It is generally accepted that most patients with PNEE fall under the somatoform category (unconscious production of symptoms), rather than the intentional faking type (malingering and factitious). However, while the DSM classification is simple in theory, it is nearly impossible to know if a given patient is faking. Intentional faking can only be diagnosed in some circumstances by catching a person in the act of faking (e.g., self-inflicting injuries, ingesting medications or eye drops to cause signs, putting blood in the urine to simulate hematuria). Malingering may be under-diagnosed, partly because the ‘diagnosis’ of malingering is essentially an accusation.

Trying to uncover intent

Neuropsychological and psychological evaluation provides potential avenues to better characterize patients with PNEE and explore intent to fake or over-report symptoms [5]. While some studies of patients with PNEE suggested the presence of mild-to-moderate neuropsychological deficits [6–8], investigations including measures of symptom validity tests (SVT), which are tests designed such that individuals with known neurological disease can perform well on these tests but these measures appear to be difficult and are sensitive to detection of suboptimal test taking effort [9]. Investigations using SVTs found a greater number of participants with a PNEE score in the range of poor effort/task engagement than do patients with epilepsy [5,10]. Drane et al. found 51% of patients with PNEE failed a SVT compared with only 8% of patients with epilepsy [5]. Subjects that failed the Word Memory Test [11] were more than 11 times more likely to be diagnosed with PNEE than with epilepsy (odds ratio: 11.33; p < 0.001). Additionally, those patients with PNEE passing the SVT tended to perform normally on neuropsychological measures. Alternatively, patients with PNEE who failed the SVT performed significantly worse than patients with confirmed epilepsy. These data suggest patients with PNEE tend to give invalid (noncredible) scores on cognitive tests, whereas patients with epilepsy tend to give more valid data [5]. While it remains controversial if the poor task engagement/attention is purposeful, these data certainly suggest that patients with PNEE put forth less motivation and/or are less attentive to tasks than patients with epilepsy. Proposed factors contributing to insufficient effort exhibited by patients with PNEE include: pain, physical fatigue, emotional distress and conscious intent. The potential for interactive and multiple factors giving raise to poor task effort/attention to tasks remains unclear, but data have emerged that the rating of pain by patients with fibromyalgia, rheumatoid arthritis and other chronic fatigue syndromes are not correlated with subjective ratings of pain intensity at time of testing [12,13]. These data highlight the finding that patients with diagnoses of conversion disorder present with psychogenic-based physical as well as cognitive symptoms [6,14], suggesting the diagnosis of conversion disorder encompass a diagnostic entity in which patients provide (or exhibit) noncredible symptoms across a variety of domains [6,14].

The DSM-V

The development of the DSM-V proposes significant changes to the DSM-IV somatoform category for conversion disorder [15,16]. Perhaps most significant is the proposed addition of the term ‘functional neurological symptom disorder’ for the DSM-V term of conversion disorder. The addition of another acceptable term for conversion disorder was introduced for two reasons: the term is more often used by neurologists who see the majority of patients receiving conversion disorder diagnoses and the term ‘functional neurological symptom disorder’ is believed to be more acceptable to patients.

Another change is the removal of the previous criterion B of the DSM-IV ‘psychological factors are judged to be associated with the symptom or deficit because the initiation or exacerbation of the symptom or deficit is preceded by conflicts or other stressors’. This criterion was removed in the hope that further research would foster a discussion of the etiological factors, with extent research placed in the forthcoming DSM-V text. This diagnostic criterion of the DSM-IV has reduced the utility and reliability of the diagnosis of conversion disorder owing to: a clinical description was confounded with a presumed etiology, data indicate psychological factors and symptoms were not specific to patients with conversion disorder diagnoses, and were found in patients with other diagnoses, often at a similar prevalence rate. The presence of nonspecific psychological factors identified as associated with conversion disorder nonspecific and not reliable for diagnosis and in at least some patient groups having a diagnosis of conversion disorder, that is neurological symptoms not explained by disease, psychological symptoms could not be convincingly found. For example, Drane et al. found a small number of patients with diagnoses of PNEE who scored normally on a symptoms validity test but exhibited poor performances on at least some neuropsychological measures and had a diagnosis of PNEE [5].

Another change to the DSM-V conversion disorder (functional neurological symptoms disorder) is the removal of the previous criterion C in the DMS-IV: ‘the symptom or deficit is not intentionally produced or feigned (as in factitious disorder or malingering)’. This criterion has reduced the reliability and utility of the conversion disorder diagnosis because it has proven very difficult to reliably demonstrate if a patient is feigning, but proving the absence of feigning symptoms may be impossible [16]. On the other hand, it has proven challenging to demonstrate whether a patient may exhibit complex behaviors without conscious control/awareness. Furthermore, while the possibility of feigning (malingering) symptoms is certainly present in conversion disorder, there are no data to indicate feigning symptoms do not occur less often among patients without a diagnosis of conversion disorder, but who have some other psychiatric diagnoses. Thus, it has been argued that highlighting feigning of symptoms in conversion disorder may be unnecessarily stigmatizing to patients with conversion disorder diagnoses.

Below, we provide the current proposed DSM-V criteria for conversion disorder (functional neurological symptom disorder):

• • One or more symptoms of deficits are present that affect voluntary motor or sensory function, with or without apparent impairment of consciousness;

• • Clinical findings provide evidence of internal inconsistency or incompatibility with recognized neurological or medical disease;

• • The symptom or deficit is not better explained by another recognized medical or DSM disorder;

• • The symptom or deficit is associated with clinically significant distress or impairment in social, occupational or other important areas of functioning or warrants medical evaluation.

While the presence of feigning symptoms may be both stigmatizing and an accusation, the further study for the etiology of PNEE and how the clinical features of PNEE occur remain an important area for clinical research and targeted clinical practice. Patients with PNEE account for a significant amount of health resource dollars and resource utilization. The long-term consequences of unnecessary treatment of PNEE, including years of antiepileptic medications, repeated radiological studies and/or entubation in the case of episodes of status PNEE are not inconsequential. Finally, further evaluating the etiology for PNEE will help to continue the development of efficacious treatments for this currently difficult to treat (refractory) diagnostic entity [15].

Financial & competing interests disclosure

MR Schoenberg has received honorarium from HCR ManorCare, Taylor and Francis, and the Scientific Peer Advisory and Review Services Division of the American Institute of Biological Sciences. SR Benbadis has served as a consultant for, has received research support from, or is on the speakers’ bureau for Cyberonics, GlaxoSmithKline, Lundbeck, Sunovion, UCB Pharma and Vertex Pharmaceuticals. MR Schoenberg has received royalties from Springer. SR Benbadis has received royalties from Emedicine-WebMD-Medscape, UpToDate and Demos. MR Schoenberg serves as Associate Editor for The Clinical Neuropsychologist, Taylor and Francis, and on the Editorial Boards of Archives of Clinical Neuropsychology, Current Gerontology and Geriatrics Research, and Psychiatry Journal. SR Benbadis serves as Editor-in-Chief (Neurology) for WebMD-Medscape, and is on the Editorial Boards of Epilepsy and Behavior, Epileptic Disorders and European Neurology. MR Schoenberg serves on the Board of Directors for the American Board of Clinical Neuropsychology, as a grant reviewer for the Epilepsy Foundation and the Scientific Peer Advisory and Review Services Division of the American Institute of Biological Sciences, and on the Guideline Committee and the Practice Management Committees, Council on Clinical Activities, American Epilepsy Society. MR Schoenberg also receives a salary from the USA Department of Defence, University of South Florida and the Florida Department of Elderly Affairs. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.