Diagnostic Overshadowing Webinar Review

18 April 2024

Jane Margetson reviews the Cerebra webinar talk on ‘Diagnostic overshadowing for children with a genetic condition associated with an intellectual disability’, led by Dr Jo Moss and Debbie Austin on 21st November 2023.

Diagnostic Overshadowing Webinar Review

18 April 2024

Jane Margetson reviews the Cerebra webinar talk on ‘Diagnostic overshadowing for children with a genetic condition associated with an intellectual disability’, led by Dr Jo Moss and Debbie Austin on 21st November 2023.

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A recording of the webinar is now available at the end of this article if you’d like to catch up in full.


Dr Jo Moss opened the webinar by placing our focus on the importance of prioritising the long term health and well-being of children and young people with a genetic condition associated with intellectual disability. Research has shown that having a genetic condition can be related to poorer outcomes, heightened inequalities within society and often more complex needs than other children.

Dr Moss went on the explain how her research aims to address some of the inequalities and help inform better support for the needs of these children and young people. She explained that knowing about a genetic syndrome can help us better understand an individual’s needs and any strengths and difficulties that they might be more likely to have. This can help professionals to prioritise any support needs.

Diagnostic overshadowing

Dr Moss explained that the term diagnostic overshadowing means that a professional may put a child’s difficulties down to a primary diagnosis, placing too much focus on the diagnosis as an explanation for symptoms or difficulty and failing to consider alternative explanations.

This can take the form of placing too much focus on a genetic diagnosis and failing to consider other diagnoses that may better explain the situation. For example, for high impulsivity in a child with a genetic syndrome, it is useful to consider at what point a child might need to be considered for an Attention Deficit Hyperactivity Disorder (ADHD) diagnosis or similar ADHD like presentations.

Identifying the correct diagnosis helps to decide which support is best. Diagnosis happens at a behavioural level and can get missed when there are other diagnoses with similar behavioural profiles. Dr Moss stressed the importance of us thinking about why the behaviour is presenting before reaching a conclusion.

Dr Moss Informed us that all of the following layers are important to fully meet a person’s needs. If you ignore any layer you might end up with diagnostic overshadowing of some kind.

Layers to consider to reduce diagnostic overshadowing:

  • Developmental differences
  • Primary diagnosis
  • Co-occurring conditions
  • Physical factors
  • Environmental factors

Parents have stated in research, that having a genetic condition can often feel like a full stop. A reason to end the conversation and offer no further explanation. Dr Moss stated that she found this point very poignant and herself stated that ‘a diagnosis should be the beginning of our enquiry, not the end’.

Multi-diagnostic pathways for neurodevelopmental conditions

Research has also found that people with neurodevelopmental conditions often have more than one. They may be treated for one condition but feel that ADHD has really been the issue, that they are not diagnosed or treated for. Thus without examining co-occurring conditions or other explanations, it’s very easy to fail to meet a person’s needs. Dr Moss is not suggesting everyone needs to go out and seek additional diagnoses. Rather she is advocating for the approach of thinking beyond the primary diagnosis a child might have, and thinking holistically about what might be going on.


Autism is a neurodevelopmental condition with a prevalence of around 1% of the population. Dr Moss highlighted that in those with a severe intellectual disability the prevalence of co-occurring autism is around 40%. There is a strong association or some overlap in the symptoms of severe intellectual disability and the symptoms of autism.

Autism is characterised by differences in two key areas, social communication and repetitive behaviours/restricted interests. It is a spectrum condition, so there is a lot of variability with how an person might experience it or in the characteristics that are displayed. The prevalence of autism is raised in children with a genetic syndrome associated with intellectual disability (Richards et al, 2015). Individuals with genetic syndromes are 10x more likely to show autism characteristics relative to the general population.

Dr Moss went on to discuss the challenges of assessing and diagnosing autism in genetic syndromes, and how diagnosis seems to be delayed. Clinicians might find it difficult to identify autism for this group of children, as the presentation of autism can be very variable for different genetic syndrome groups.

Each group has its own pattern of autism characteristics. Knowing what the autism profile of characteristics is for the condition you are interested in is likely to be useful. This research showing a heat map of profiles of autism characteristics in thirteen genetic syndromes is useful to view.

What can parents do to advocate for their child to ensure diagnostic overshadowing is least likely to happen?

  1. Think about the layers described above in relation to your child and the specific needs they have. Decide if you think support is adequate or if you think something is being missed that would make a big difference to your child.
  2. Raise it with the professionals you’re working with and encourage them to consider the layers too if they are not already.
  3. Together, see if you can pin point where a change can be made.

A parents perspective on diagnostic overshadowing

Debbie Austin, is a mother to a daughter with Down syndrome and a Strategic Workforce Development Manager for Family Carers in the NHS. Debbie spoke from personal experience about factors at the behavioural level (physical and environmental factors) that might be important to consider when thinking about why a behaviour or difficulty is presenting for a young person. Debbie introduced us to her 15 year old daughter, Lucy, and explained how getting an early diagnosis of autism, alongside her primary Down syndrome diagnosis was so important and useful for them as a family.

Lucy received a diagnosis of autism when she was 5. Debbie highlighted that Lucy has lots of passions and that knowing about these are important to understand in relation to the way Lucy behaves. Debbie explained how Lucy uses her strengths and passions to navigate what is actually quite a confusing world.

Lucy has a severe learning disability and high support needs. All her needs are anticipated and supported, as she cannot communicate how she feels verbally. She experiences a lot of anxiety. Having diagnosis of Down syndrome and autism puts Lucy at risk of diagnostic overshadowing. Debbie explained that she see’s diagnostic overshadowing as a great injustice, and thinking of it this way, makes positive action more likely to be taken to more fully understand the situation and get justice for the person in the world.

Debbie explained that diagnostic overshadowing could happen with regard to a person’s social need for communication and connection. Certain behaviours might be displayed and might be misunderstood in this context. It could be a medical need e.g. not feeling well, any behaviours might be overlooked as an indication of illness and put down to any diagnosis they have. Or Debbie explained that it could be an environmental need, e.g. the person doesn’t like what is going on around them. Behaviours that are considered to be concerning by others might be displayed.

Debbie highlighted that medication is also an issue, it is common for people with learning disabilities to not receive the medication they need for a health condition. This is particularly common in relation to being treated for pain and given appropriate pain medication. In contrast inappropriate medication can also be given. This is beginning to be addressed with the STOMP STAMP agenda. Reducing the prescribing of antipsychotic medication unnecessarily.


This webinar made it clear that more needs to be done to make the advocating process much easier for families of children with rare genetic syndromes. The Further Inform Neurogenetic Disorders website is a great place to learn more about a number of rare genetic syndromes and common support issues that may be experienced.

The Be-well Checklist is a useful tool to think about important aspects relating to your child’s well-being and may help to reduce the likelihood of some diagnostic overshadowing.

In addition, the Find Teacher Resources website is a fantastic resource to share with your child’s educators to help reduce any diagnostic overshadowing in school.

To find out more about current research projects being undertaken to understand and support children with neurodevelopmental disorders and rare genetic syndromes and their families, please visit The Cerebra Network for Neurodevelopmental Disorders website.


Please find below the resources and research that were mentioned during the webinar.


My communication passport
Cerebra Parent Guides
Challenging Behaviour Foundation
Yvonne Newbold TED talk


Embracing complexity in diagnosis – Multi-diagnostic pathways for neurodevelopmental conditions.

Diagnostic overshadowing holds me back. Down Syndrome Research Foundation

Delegate feedback about the webinar

‘My main takeaway from this event was to always first consider that could there be something else going on rather than assuming it’s the main diagnosis’.

‘More focus should be on identifying a person’s needs and meeting them’.

‘I have never felt that my son was wanted by society, until I attended this event’.

Dr Jo Moss is a Senior Lecturer in the School of Psychology at the University of Surrey, and Co-Director of the Cerebra Network for Neurodevelopmental Disorders.

Debbie Austin is a Strategic Workforce Development Manager for Family Carers in the NHS.

Jane Margetson is a Lead Research and Education Officer at the Charity Cerebra.


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