Non-standard diagnostic terms are very often defined quite differently, depending on who is using them, and they also do not have set criteria for diagnosing them. The overall term, Specific Learning Difficulty (SpLD), has become increasingly used to refer to some or most of them, including ADHD. There is nothing necessarily problematic about this but it does mean that it can be unclear what is being referred to, what sort of severity level it is at, whether it would constitute a disability under the Equality Act 2010 and so on. The other issue is that it tends to leave out some NDD (like autism) and group motor and impulsivity problems together with information processing issues in a somewhat confusing way.
There are several reasons for the popularity of non-standard terms:
- They are often felt to be less stigmatising
- They can be used to include people with a difficulty that has not reached a clinically significant level
- It is often thought important to have a specific term for each mix of identified problems
Why the confusion?
A key issue is that standardised diagnoses do not include anything about underlying causes. This means the diagnosis is given purely on the basis of the observed or identified problem (following a full assessment covering all the relevant criteria). For example, if you have a difficulty with word reading that causes significant interference with academic performance, that has lasted for at least six months and has not responded to appropriate interventions, then you can be given a diagnosis of specific learning disorder with impairment in reading (specifier: word read accuracy). There is no need to know anything about the underlying neuro-cognitive issues to be able to give this diagnosis.
That is not to say that the underlying issues are not important or are not assessed for: it is just that they do not form part of the diagnosis. Non-standard terms, however, tend to have additional components added onto them that are explanatory, causal or just co-morbid. This can have the effect of making it seem like a wide variety of other issues are an inherent part of the diagnosis whereas they either just tend to co-occur with that issue or are part of the underlying cause.
For example, dyslexia is best understood as a problem of accurate and fluent word reading and spelling: it is no more or less than that and would correspond with the formal diagnoses specific learning disorder with impairment in reading (specifier: word reading accuracy) and specific learning disorder with impairment in written expression (specifier: spelling accuracy) – the two diagnoses would be given together when both problems occur but the problems are not always seen in conjunction.
In general, though, NDD are highly comorbid – that is, they tend to co-occur, overlap and not appear in neatly defined ways – and it was noticed that lots of people with dyslexia also had a variety of other neurodevelopmental issues. Also, more was discovered about the underlying causes of reading and spelling problems, like poor phonological processing (i.e. problems with word sounds). Over time, these things came to be talked about as if they are dyslexia rather than being associated with or causes of dyslexia.
In 2009, a significant independent report (Identifying and Teaching Children and Young People with Dyslexia and Literacy Difficulties by Sir Jim Rose) highlighted this issue and clearly stated that, “Co-occurring difficulties may be seen in aspects of language, motor co-ordination, mental calculation, concentration and personal organisation, but these are not, by themselves, markers of dyslexia.”
Whilst this is now a well-recognised position, you will often see a variety of other statements made about dyslexia, for example: “It is characterised by difficulties with phonological processing, rapid naming, working memory, processing speed, and the automatic development of skills that may not match up to an individual's other cognitive abilities.” Often, these sorts of things are entirely correct but are not particular to dyslexia and are in fact seen across a broad range of NDD.
Why does this matter?
The main problems that can arise with non-standard diagnoses are:
- Lack of clarity about what is actually being referred to
- Failure to properly identify and diagnose co-morbid issues
- Confusion about whether something is an observed problem or possible underlying causal factor
- Assessments being restricted to a certain issue rather than starting from the question: What seems to be the problem here?
This can then give rise to incomplete analyses and recommendations: unless the full range of neurodevelopmental issues has been assessed for and considered, it will be impossible to properly understand why a child or student is experiencing the difficulties they are.
A full assessment of educational or neurodevelopmental issues will, therefore, always look at (i) the identified or presenting problems so as to provide accurate diagnoses and (ii) the underlying or causal neuropsychological factors. So, the diagnoses might be of a Specific Learning Disorder or an Other Specified Neurodevelopmental Disorder, but, the underlying factors might relate to phonological processing, information sequencing, visual processing or scanning speed and so on. And sometimes the underlying causes remain rather unclear, perhaps because rather subtle issues have combined in unexpected ways. This can occur when, for example, there is a large discrepancy between different areas of cognitive functioning without any one of them being below average: it is the discrepancy that causes the impairment rather than any objectively low score.
