ICD-11 Mental Health TAG opposes inclusion of “Functional clinical forms of the nervous system” under neurological conditions

Post #318 Shortlink: http://wp.me/pKrrB-42P

Update: In September, a series of ICD-11 Symposia were held at the World Psychiatric Association XVI World Congress, in Madrid. These included Symposium Code SY469: Proposals and evidence for the ICD-11 classification of dissociative disorders, the abstract for which can be found here (pages 354-355).

Update: For those registered for enhanced access to the public version of the ICD-11 Beta drafting platform, there are some recent proposals on behalf of Mental Health TAG for the Dissociative disorders block, here.


As previously posted:

In my September post, Briefing paper on ICD-11 and PVFS, ME and CFS: Part 2, I reported on a proposal by the ICD-11 Topic Advisory Group (TAG) for Neurology for the inclusion of a disorder group termed, “Functional clinical forms of the nervous system,” under Neurological conditions.

Under this new parent class, it has been proposed to locate a list of “functional disorders” (Functional paralysis or weakness; Functional sensory disorder; Functional movement disorder; Functional gait disorder; Functional cognitive disorder, Functional visual loss etc.).

In ICD-10, these conditions are accommodated under the Chapter V F44 Dissociative [conversion] disorders section.

In DSM-5, they are classified under “Conversion Disorder (Functional Neurological Symptom Disorder),” which is one of several categories that sit under the DSM-5 “Somatic Symptom and Related Disorders” section. They are cross-walked to ICD-10-CM’s F44.4 to F44.7 codes, depending on the symptom type.

The rationale for this proposed new parent class is set out in this recent paper by Stone et al:

Functional disorders in the Neurology section of ICD-11: A landmark opportunity

Jon Stone, FRCP, Mark Hallett, MD, Alan Carson, FRCPsych, Donna Bergen, MD and Raad Shakir, FRCP*

Neurology December 9, 2014 vol. 83 no. 24 2299-2301

doi: 10.1212/WNL.0000000000001063

Full free text

Full free PDF

*Raad Shakir chairs the Topic Advisory Group for Neurology

See also (full paper behind paywall):

Functional neurological disorders: The neurological assessment as treatment. Stone J. Neurophysiol Clin. 2014 Oct;44(4):363-73 Abstract: http://www.ncbi.nlm.nih.gov/pubmed/25306077


Opposition from Mental Health TAG

If you are registered for increased access to the public version of the Beta drafting platform, you can read the response from Mental Health TAG, here.

If you are not registered, see below:

Proposal for Deletion of the Entity

Functional clinical forms of the nervous system

Proposal Status: Submitted


Definition does not exist for this content


This grouping should be deleted.

These are by definition not neurological conditions, as indicated by the phrase included in the definitions provided: ‘in which there is positive evidence of either internal inconsistency or incongruity with other neurological disorders’. If there is no evidence of a neurological mechanism or etiology, the rationale for including these in the classification of neurological disorders is unclear to say the least.

In contrast, these have always been viewed as mental disorders (from the days of Sigmund Freud), and there is no evidence about their etiology or mechanism that is inconsistent with that formulation.

Prior to ICD-10, these conditions were conceptualized as Conversion Disorders. This terms is considered obsolete because it refers to a psychodynamic mechanism that is theoretical and not ideally descriptive. ICD-10 offered a transitional title, calling them Dissociative [conversion] disorders.

For ICD-11, the proposals for Mental and Behavioural Disorders refer to these as Dissociative disorders, dropping the ‘Conversion’ part of the term. Dissociative disorders are defined descriptively, as ‘characterized by disruption or discontinuity in the normal integration of memories of the past, awareness of identity, immediate sensations, and control over bodily movements that are not better explained by another mental and behavioural disorder, are not due to the direct effects of a substance or medication, and are not due to a neurological condition, sleep-wake disorder, or other disorder or disease. This disruption or discontinuity may be complete, but is more commonly partial, and can vary from day to day or even from hour to hour.’ There is not basis for suggesting that this formulation is inconsistent with the phenomena proposed for inclusion here as ‘Functional clinical forms of the nervous system’.

The fact that neurologists may be asked to evaluate these conditions is not an adequate rationale for defining them as neurological disorders, nor are concerns about reimbursement policies that are unwisely based on divisions among specialists’ scope of practice based on ICD chapters.

The Mental Health TAG is aware that there is a vocal group of advocates for this terminology among neurologists. In fact, this terminology was included as alternate terminology in DSM-5. However, in DSM-5, these are still very clearly classified as Mental disorders.

Similarly, these terms can be added as inclusion terms to the equivalent categories in the Mental and behavioural disorders chapter.

In spite of its popularity among at least some neurologists, this terminology is currently viewed in psychiatry as obsolete, and based on a mind-body split (division between ‘organic’ and ‘non-organic’) we are elsewhere attempting to remove from the ICD-11. The implied contrast is between a ‘real’ (medical) disorder and a ‘functional’ (psychiatric) disorder.

A further problem with this terminology is its inconsistency with WHO’s official policy use of terminology related to ‘functioning’ (function, functional), as defined in the ICF.

In some instances of the use of the term ‘functional’ in other parts of proposals for ICD-11, it is not clear that the proposals use the term ‘functional’ in this same sense, or if they mean something close to ‘idiopathic’. However, it is quite clear that what is meant in this group of proposals is ‘without neurological explanation or plausible or demonstrable etiology’.

However, this terminology is in any case problematic. In addition to requesting that this group of categories be deleted from the classification and instead integrated appropriately as inclusion terms in the chapter on Mental and Behavioural Disorders, the Mental Health TAG requests that the Classifications Team examine other uses of the term ‘functional’ in proposals for ICD-11 and consider either appropriate parenting in Mental and behavioural disorders or alternative terminology.

The Mental Health TAG also requests that this issue be revised by the Revision Steering Group (and or Small Executive Group) in order to arrive at an ICD-wide solution as efficiently as possible. The Mental Health TAG requests that this issue not simply be arbitrated by the same TAGs that have made these proposals.

–On behalf of Mental Health TAG


There are no references attached for this proposal item

Comments on this proposal


The Mental Health TAG also requests that this issue be revised by the Revision Steering Group (and or Small Executive Group) in order to arrive at an ICD-wide solution as efficiently as possible. The Mental Health TAG requests that this issue not simply be arbitrated by the same TAGs that have made these proposals.

–On behalf of the Mental Health TAG
Geoffrey Reed 2015-Jan-10 – 23:10



An alternative could be that this grouping could be retained but with appropriate primary parenting to Dissociative disorders in the Mental and behavioural disorders chapter.

Entities of ‘functional clinical forms’ have already been proposed to be added in the appropriate categories in Dissociative disorders. Most of them are included in Dissociative motor disorder, though several are included in Dissociative disorder of sensation. One is included in dissociative amnesia.

However, the name of these entries – i.e., functional disorders – remains an issue as described above, which should be resolved at the ICD-wide level.

Note that if the solution selected involved retaining these categories, perhaps renamed, but primary parenting them appropriately in Dissociative disorders, it will be more appropriate to move the secondary parented categories to the main Disease of the nervous system chapter rather than listing them in clinical forms.

–On behalf of the Mental Health TAG
Geoffrey Reed 2015-Jan-12 – 09:14 UTC


I will update if further comment is uploaded on behalf of the Mental Health TAG, the Neurology TAG, ICD-11 Revision Steering Group, the WHO classification experts etc.


Note for stakeholders with an interest in the ICD-10 G93.3 categories: There is currently no inclusion within any chapter of the ICD-11 Beta draft for a specific parent class for “Functional somatic syndromes,” or “Functional somatic disorders” or “interface disorders” under which, conceivably, those who consider CFS, ME, IBS, FM et al to be speciality driven manifestations of a similar underlying functional disorder might be keen to see these terms aggregated.

On July 24, 2014, ICD Revision’s Dr Geoffrey Reed stated there has been no proposal and no intention to include ME or other conditions such as fibromyalgia or chronic fatigue syndrome in the classification of mental disorders.


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