By Christian Jarrett

Given how important maths skills are in everyday life, it is vital that we develop ways to reliably identify those children with particular learning difficulties related to maths (known as “specific learning disorder in mathematics”/SLDM or dyscalculia) so that they can be provided with appropriate support. Unfortunately, maths-related learning problems are far less understood and recognised compared with similar problems related to reading and language.

A recent study in the British Journal of Psychology highlights this issue, being the first to estimate the prevalence of SLDM/dyscalculia in primary school age children using contemporary criteria (as outlined by the American Psychiatric Association in the latest version of its diagnostic manual). The results provide much needed data on this topic, reveal some worrying facts and also useful insights for policy.

The research is based on nearly 2,500 children, aged 7 to 13, from 19 rural and urban schools in Northern Ireland. The data are averages of several years’ standardised test results of the children’s maths, reading and IQ, together with background demographic information and notes on any diagnoses of other developmental problems.

Historically, diagnosis of SLDM/dyscalculia took a child’s IQ into account a child, such that a specific problem with maths was only diagnosed if their maths ability was low relative to their IQ – the so-called “discrepancy criterion”. The newer diagnostic criteria (in DSM 5) abandon this principle. Now a persistent, significant problem with maths counts as SLDM/dyscalculia even if it occurs alongside comparably low IQ or other learning problems (however SLDM is still discounted in the context of extremely low IQ).

Based on the new criteria, Kinga Morsanyi and her colleagues at Queen’s University Belfast, estimated the relevance of SLDM/dyscalculia in primary school children at around 6 per cent. This is substantially higher than previous estimates of 1.1 per cent prevalence based on the earlier diagnostic criteria. Morsanyi’s team said this could have “huge consequences for children’s outcomes” because it means more children ought to be able to access maths-based educational support.

Somewhat worryingly, however, the data showed that only one child in the sample had actually received a formal diagnosis of SLDM/dyscalculia, in contrast with 108 children who had received a diagnosis of dyslexia. Given that prevalence rates of SLDM/dyscalculia and dyslexia are usually similar, the researchers explained that this means “we can say that a child with dyslexia was more than a hundred times more likely to receive an official diagnosis of that disorder (which is necessary to obtain specialist educational support) than a child with dyscalculia.”

In theory, the revamped diagnostic criteria ought to lead to the identification of more children with SLDM/dyscalculia, thus opening up the chance for them to receive specialist support, but in practice this does not seem to be happening. At least, not yet. Moreover, from speaking to educational psychologists, Morsanyi and her team said the situation is compounded by the fact the educational psychologists said there are “no generally accepted intervention methods that could be recommended” for SLDM (a further complication is that the new diagnostic criteria state that maths problems should be persistent in spite of interventions, which promotes the unhelpful idea that extra support for children with SLDM/dyscalculia is futile – the researchers challenge this view and point to their finding of reduced prevalence of SLDM/dyscalculia with age as evidence that persistent maths problems can be addressed effectively).

“An important first step,” to addressing these issues, they said, “would be to raise awareness of SLDM/dyscalculia among both teachers and educational psychologists as part of their work training.”

In terms of demographic background and other concurrent diagnoses, the new data suggest that children with persistent maths problems also often have problems with English and low IQ; tend to come from relatively deprived backgrounds; usually have other special educational needs; and are more likely to have “newcomer status” (meaning that English wasn’t their first language). The researchers said that additional support for maths should be given to children with SLDM/dyscalculia regardless of the source of their maths problems (be they environmental or cognitive or a mix of the two). They also noted that there were some children with SLDM/dyscalculia who also had a diagnosis of autism, but none with a concurrent diagnosis of ADHD.

A final finding to note concerns gender differences – overall, there was no evidence that girls or boys were more likely to have dyscalculia/SLDM (or be exceptional in maths), which contrasts with the situation for dyslexia, which is about twice as common among boys. However, when the researchers matched girls and boys for IQ and English scores (which were generally higher in girls overall) and special educational needs status, there was evidence of more maths problems among girls than similar status boys – what the researchers described as “… a hidden gender difference in maths performance even among primary school children. That is, although girls do not underperform in terms of their actual scores, they underperform relative to their cognitive/learning potential”. Considering reports that many girls lose interest in maths and science at around age 11, the researchers said another policy implication of their results was that intervention programmes aimed at encouraging girls into science and maths subjects should start even earlier.

In a prepared media statement, Morsanyi wrote that “From these figures, we can estimate that about 10,000 children in Northern Ireland have sustained, serious difficulties with mathematics. Given that virtually no children in our sample received an official diagnosis of mathematics disorder, we can expect that most of these children do not receive educational support with mathematics. This can have very important adverse consequences.” She added that “…these figures in the UK in general would be much higher.”

—The prevalence of specific learning disorder in mathematics and comorbidity with other developmental disorders in primary school-age children

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest