Page 4 US patient 1 to J 00 SSD and J 02 Conversion Disorder (FNSD)
Mayou et al wrote of the somatoform disorders: “Abolish the somatoform disorder category. The somatoform disorder term, concept, and category have failed psychiatrists, nonpsychiatric physicians, and patients. There seems to be little reason to retain them.” 4 Mayou et al criticized the existing somatization disorder definition in part because it relies on “counting the number of ‘unexplained’ somatic symptoms and so lacks even face validity as a psychiatric disorder”. But the DSM-5 SSD Work Group’s ‘solution’ is to simply remove the stricture of counting ‘unexplained’ symptoms within a specified distribution and instead have the entire diagnosis depend on the clinician’s subjective assessment of whether patient has been worrying too much about a given symptom, and whether that symptom warrants so much concern or interest to begin with.
In other words the Work Group is replacing what was at best a fairly arbitrary scoring and ‘counting’ of possibly psychogenic symptoms with something even worse; all a clinician will have to do now is perceive a single symptom as the excessive focus of a patient’s concern or time in order to give them a psychiatric diagnosis. That lowers the threshold of symptoms identified as potentially psychiatric in origin from 13 (DSM-III-R) to as little as 1 required for diagnosis. As noted by Johnson et al, lowering that threshold can lead to dramatic overdiagnosis of patients with somatoform disorder diagnoses. How would SSD criteria have fared in that study? One can predict that both SSD and USD criteria would have performed abysmally in the CFS patients groups, and that while the USD criteria may have overdiagnosed the MS patient group, the SSD criteria would have done so at a much higher rate.
Psychiatry does not have the tools to insure that a practitioner can accurately determine the relative weight of contributing factors – somatic or psychiatric – to a patient’s symptoms or overall condition. Yet the diagnostic framework of the proposed SSD diagnosis is built on the assumption that such tools exist. As they do not, SSD must be regarded as an untenable diagnostic entity.
There are similar basic flaws in the suggested DSM-5 criteria for Conversion Disorder. Like other diagnoses that have been grouped in the somatoform disorders category, conversion disorder is based on a speculative mechanism that is the product of conjecture and outmoded psychiatric theories, and it is nonscientific because it does not allow for the development of falsifiable hypotheses. Nevertheless, it has appeared in one form or another in all DSM editions to this point; its criteria in DSM-IV-TR are as follows:
“A. One or more symptoms or deficits affecting voluntary motor or sensory function that suggest a neurological or other general medical condition.
B. 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.
C. The symptom or deficit is not intentionally produced or feigned (as in Factitious Disorder or Malingering).
D. The symptom or deficit cannot, after appropriate investigation, be fully explained by a general medical condition, or by the direct effects of a substance, or as a culturally sanctioned behavior or experience.
E. The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.
F. The symptom or deficit is not limited to pain or sexual dysfunction, does not occur exclusively during the course of Somatization Disorder, and is not better accounted for by another mental disorder.” 5
If the mechanism of conversion disorder is based on speculative hypothesis with no empirical validation, how can conversion disorder ever be said to better account for symptoms that are not fully explained by a ‘general medical condition’? How can it be a preferred explanation to any unknown or equally hypothetical medical condition?
Thus, the diagnosis of conversion disorder is of dubious clinical validity to begin with. But again, instead of addressing this problem, the SSD Work Group has only made this diagnosis less specific by removing Criteria B and C from the DSM-IV version. This results in criteria that are so non-specific that not only do they technically qualify as a subset of Somatic Symptom Disorder – it is not immediately clear how the two could be distinguished, and on what basis Criterion C would lead one to prefer a conversion disorder diagnosis over SSD, since SSD may also apply to “a symptom affecting voluntary motor or sensory function” – but they also no longer contain any requirement of evidence of psychopathology. A diagnosis that is based on absence of evidence rather than positive signs will capture any case that is not readily explained by standard medical workups or by well-known disease processes.
Clearly, then, the proposed DSM-5 conversion disorder is little more than a dustbin diagnosis for unexplained neurological symptoms. Is it accurate or ethical for such a dustbin category, which is designed NOT to be specific to psychiatric etiologies, to be defined as psychiatric? One of the rationales given on the DSM-5 site for removing criterion B is that the latter “confounds clinical description with a proposed but unproven etiology”. But having a DSM diagnosis by definition implies psychiatric, or at least non-somatic, etiology, and therefore patients who have purely somatic neurological problems could be easily mislabeled by these criteria with what is viewed as predominantly psychiatric illness. This in turn could lead to many harmful ramifications for the patient, including a premature end to investigation into the true cause for their symptoms, inappropriate treatment recommendations, and termination of health benefits.