Are we dealing with a genuine increase in autism among pre-school children?

Science Norway, along with other media that report research findings to the wider public, has an established practice of reporting findings only after results have been published in a recognised academic journal. Based on such novel findings, a specific issue is then seen in a broader context and discussed from a number of perspectives.

This, however, does not appear to have been the case for the article 'Autism rates are rising. Researchers say it cannot solely be explained by more people being diagnosed.'

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Autism rates are rising. Researchers say it cannot solely be explained by more people being diagnosed

The piece published on September 18 does not report results from any research study or survey. Instead, it mainly reflects the views of a particular professional and serves as a somewhat inconsistent continuation of claims first made in Aftenposten (June 5).

The June 5th publication refers to isolated studies from very different populations in an ad hoc fashion, often misrepresenting the findings. This applies, for example, to the results of the study used to support the idea of a potential link between autism and screen use among pre-school children.

The latter claim sparked a heated debate in the media in June and July this year.

Let’s look at the facts

The prevalence of autism is rising across countries and cultures. This is true. This prevalence varies depending on country, referral paths, and diagnostic criteria. The most accurate explanation of what this might be due to comes from 'Epidemiology of Autism Spectrum Disorders' by Hill, Zuckerman & Fombonne (2014):

'Epidemiological surveys of autism spectrum disorders (ASDs) have been performed since the mid-1960s. Methodological differences make between-survey comparisons difficult to perform, thus making it difficult to evaluate actual prevalence of ASDs over time. Surveys from the 1990s show an increase in ASD diagnosis in most countries. Evidence suggests this rise does not indicate an actual increase in incidence (an epidemic.

Instead, the upward trend is probably related to changes in concepts, definitions, services availability, and awareness of ASDs among general population and professionals. Correlates that can affect the accuracy of these survey figures include socioeconomic status, race/ethnicity, and immigrant status.'

This quote also suggests that factors, such as socioeconomic status, race/ethnicity, and immigrant status can affect the accuracy of those figures, and this is what needs interpretation and serious research.

Autistic children of mothers born outside of Norway were diagnosed earlier

The most recent report on prevalence in the USA (Centers for Disease Control and Prevention, MWRM Surveillance Summaries) indicates that the increased identification of autism, particularly among very young children and previously underidentified groups (e.g., minority groups), underscores the increased demand and ongoing need for enhanced planning to provide equitable diagnostic, treatment, and support services for all children with ASD.

Importantly, the Sør-Trøndelag study, cited here to support the claim of a higher autism risk among children born to migrant mothers, notes that their results are open to interpretation and that they

'(...) cannot rule out the possibility that some of the variance in ADOS scores found in this study could be attributed to reduced validity of the ADOS scoring as a diagnostic tool when the child and healthcare professional do not speak the same language or share the same cultural background.'

This study also reports that autistic children of mothers born outside of Norway were diagnosed earlier than those of Norwegian-born mothers.

Language, language, and language again

This brings us to the point of bilingualism in the context of neurodevelopmental disorders.

The issue of diagnosing children with a multilingual background has long been at the forefront of research and a point of concern for practitioners. One major challenge is deciding which criteria to use when the child or their parents do not share the same language as the diagnostic team.

Cultural practices across countries have been investigated in major Europe-wide networks, focusing on better assessment methods and on interventions to improve the language skills of children with language impairment.

A large survey of speech and language therapists (SLTs) across Europe shows that many do not feel well equipped to face the challenges of multilingual patients and families. This survey also highlights that SLTs mainly work in their country's primary language.

These findings indicate that language barriers may partly explain the higher rates of developmental disorder diagnoses. A child still learning the majority language may present with symptoms that are otherwise common to developmental disorders.

This issue has been addressed in excellent research by the Bergen dyslexia group, led by Turid Helland and Frøydis Morken, which also lists concrete criteria useful for practice.

Whose practice is reflected?

In the Science Norway article, Tryti asserts that the diagnostic criteria for autism have not changed since the late 1990s. "These criteria are the same, and they're very strict," he says.

It is further stated:

"Tryti explains that children who meet these diagnostic criteria often have very limited eye contact, develop language very late, and struggle to use language socially."

Just to put this straight: The diagnostic criteria for autism have changed. Since the DSM-5, language delay or impairment is no longer part of the diagnostic criteria. The two clusters of criteria include: 

(A) persistent deficits in social communication and social interaction across multiple contexts; and (B) restricted, repetitive patterns of behaviour, interests, or activities.

Given that the first version of DSM-5 was released in 2013, it is cause for concern to insist that the diagnostic criteria have not changed since the late 1990s. This raises the question of whose practice this statement reflects.

The take-home

The bottom line is summed up by Alexandra Havdahl of the Norwegian Institute of Public Health, who confirms "(...) that a significant part of the trend reflects greater awareness, alongside changes in diagnostic criteria and referral practices."

The focus should be on how we can help the children and their families. This is indeed our task and one thing we can all agree on. Better referral practices, early response to parental concerns, early intervention, and shorter waiting times should be our main path of action. 

Equally important is ensuring that practitioners working with children receive up-to-date training, enabling them to meet the challenges of a changing societal climate.

This is entirely achievable: Norway can boast excellent research and higher education environments in this respect, so let’s make use of this synergy.

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