SELECTIVE MUTISM INFORMATION & RESEARCH ASSOCIATION
Registered Charity No. 1022673
One question that comes up frequently, with relation to Selective Mutism, is how can we diagnose SM in a case where the patient also has a diagnosis for another disorder such as ASD? At SMIRA we have seen many cases of comorbid (or co-existing) SM with other disorders particularly those on the Autism Spectrum (ASD). Many of the diagnoses of SM precede ASD assessments, although some SM assessments do come after an ASD assessment. The problem we see is that in some cases the SM assessment is not performed because it is assumed that the ASD assessment is enough to explain all of the behaviours apparent in the patient.
SMIRA’s position on diagnosis of SM:
a. Diagnosing practitioners should make an assessment for SM where they believe the patient meets the criteria for such a diagnosis.
The preferred diagnostic criteria prior to the publication of ICD-11 in 2018 were those published in APA DSM5, which lists SM as an anxiety disorder. ICD-11 classifies SM as an ‘Anxiety or Fear Related Disorder’. It lists as exclusions:
- Schizophrenia
- Transient mutism as part of separation anxiety in young children
- Autism spectrum disorder
Exclusions in the context of ICD-11 are ‘terms which are classified elsewhere’ and which ‘serve as a cross reference in ICD and help to delimitate the boundaries of a category’. This means that SM and ASD are classified as separate disorders and can therefore be diagnosed as co-morbid. This differs from the definition of exclusions used in DSM5 as ‘does not occur exclusively’.
b. Diagnosing practitioners should make a separate diagnosis for SM even if there is a pre-existing diagnosis for another disorder. SMIRA believes that ‘excluding’ SM as a comorbid diagnosis in DSM5 has been very unhelpful to medical practitioners and their patients. This is especially true in the case of ASD. We believe a person with ASD can also be selectively/situationally mute (SM), and this is allowable using ICD-11 classification.
This position is made clear in The Selective Mutism Resource Manual 2nd Edition and in Tackling Selective Mutism, the latter being endorsed by Professor Sir Michael Rutter (Institute of Psychiatry, King’s College London).
Alice Sluckin and Benita-Rae Smith (2016)
Revised Shirley Landrock-White (November 2018)
References:
icd.who.int (Accessed 6/11/18)
The Selective Mutism Resource Manual 2nd Edition, Johnson & Wintgens, Speechmark Publishing Ltd, London (2016)
Tackling Selective Mutism, Smith and Sluckin, Jessica Kingsley Publishers, London (2015).
© Copyright 2018 SMIRA
