The curious connection between hypermobility and neurodivergence

by Dr J Eccles MRCPsych MSc Ph,

Patron of SEDSConnective

Funded by the MRC, MQ Mental Health Research and Versus Arthritis, I led a team of researchers at Brighton and Sussex Medical School (BSMS) on this exciting research project. This year we were able to publish the paper that reported the results, ‘Joint Hypermobility Links Neurodivergence to Dysautonomia and Pain.’

What are neurodivergent conditions?

Neurodivergent conditions include Autism, ADHD and Tourette syndrome, alongside dyslexia, dyspraxia, dyscalculia and others. Neurodivergence is a way of thinking, feeling and experiencing the world differently. Historically these conditions have been thought of as disorders, but we affirm that they are differences, which come both with strengths and difficulties.

Overview of the research: The research into the relationship between neurodivergent conditions and hypermobility found that more than 50% of participants with a diagnosis of Autism, attention deficit hyperactivity disorder (ADHD) or tic disorder (Tourette syndrome) demonstrated elevated levels of hypermobility, compared with just 20% of participants from the general population.

Neurodivergent participants also reported significantly more symptoms of pain and dysautonomia (eg, dizziness on standing up) than the comparison group and this was related to the number of hypermobile joints.

I believe this study is further proof of the link between neurodivergence and physical health issues, demonstrating a direct relationship between hypermobility and increased pain and dysautonomia.

It is clear that health providers need to make improvements to their services to make them more accessible to neurodivergent and hypermobile patients. They also need to move beyond “exclusive” diagnostic categories and traditional boundaries between body and brain that can lead to siloed healthcare.”

This is the first study to make this connection in Tourette syndrome and also to consider neurodivergent conditions together rather than as separate diagnostic groups.

The study aligned with the Neurodiversity movement, aiming to use non ableist language to describe conditions such as autism, and neurodivergent individuals were part of the research team.

Other partners included Sussex Partnership NHS Trust, the Autonomic Unit, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, Guy’s and St Thomas’ NHS Foundation Trust, St Mary’s Hospital London and Imperial College London

Our aim:

Autism, attention deficit hyperactivity disorder (ADHD), and tic disorder (Tourette syndrome; TS) are neurodevelopmental conditions that frequently co-occur and impact on psychological, social, and emotional processes. Increased likelihood of chronic physical symptoms, including fatigue and pain, are also recognised. Over the years there have been several published case-reports of the association between autism/ADHD and hypermobility, including small studies in children. At the same time there is increasing awareness of autonomic dysfunction and pain in neurodivergent conditions. A few years ago a Swedish population study made clear a link between autism/ADHD and hypermobility/EDS. We wanted to explore whether hypermobility was more common in neurodivergent individuals and whether hypermobility explains why neurodivergent individuals are more likely to experience autonomic dysfunction and pain. We were also interested to see whether hypermobility is associated with Tourette syndrome, given how frequently it co-occurs with ADHD/autism.

Here, we tested for increased levels of joint hypermobility and symptoms suggesting overactive involuntary nervous system issues and musculoskeletal symptoms in 109 adults with neurodevelopmental condition diagnoses.

What we did:

Generalised joint hypermobility (GJH, hypermobility) was determined by physical examination incorporating the Beighton scale in adults with a formal diagnosis of neurodevelopmental conditions (the neurodivergent group, number = 109) and were compared to those in the general population in UK. This measure uses a Beighton scale cut-off of 4 in line with the older Brighton criteria for Joint Hypermobility Syndrome.

Levels of orthostatic intolerance (symptoms relating to difficulties on standing) and musculoskeletal symptoms were compared to a separate comparison group (number = 57) without diagnoses of neurological or neurodevelopmental conditions. Age specific cut-offs for GJH were possible to determine in the neurodivergent and comparison group only. This was done so we could look at levels of generalised joint hypermobility as described by the hEDS 2017 criteria.

What we found:

Levels of hypermobility

The neurodivergent group manifested elevated levels of hypermobility (51%) compared to the general population rate of 20% and a comparison population (17.5%). Using the more stringent age specific cut-off (hEDS criteria) , in the neurodivergent group this level was 28.4%, more than double than the comparison group (12.5%). There were interesting differences between males and females. Statistical analysis suggests that neurodivergent people are 4 times as likely to be hypermobile than the general population, and this is more likely for females. The picture below shows different levels of hypermobility (determined by cut-off of 4 on Beighton Scale) in the different neurodivergent groups in contrast to the comparison group. The line (error bars) indicate how precise we can be about the results. Part B demonstrates the same findings but using the hEDS age specific cut-off for GJH

Comparison of UMDS and IMDS Scores by Gender Across Different ConditionsThis figure illustrates the percentage of UMDS (Panel A) and IMDS (Panel B) scores, with error bars representing 95% confidence intervals, for males and females across four groups: ADHD, Autism, Tourette syndrome, and a comparison group. Males and females are color-coded for clarity.

Link with physical symptoms

Neurodivergent participants reported significantly more symptoms of orthostatic intolerance (symptoms related to standing up) and these symptoms tracked with number of hypermobile joints as you see from the charts below:

Graph illustrating the positive correlation between Beighton scores and Orthostatic Intolerance Symptom Scores, with error bars representing ±1 SEM.

Neurodivergent participants reported significantly more musculoskeletal symptoms and these symptoms tracked with number of hypermobile joints as you see from the charts below:

Scatter plot illustrating the positive correlation between Beighton scores and Musculoskeletal Symptoms scores, with error bars representing +/- 1 SEM. The trend line suggests increased symptoms with higher flexibility scores.

When performing a statistical analysis to look at what was driving the relationship between neurodivergence and physical symptoms we found that hypermobility was the likely mechanistic factor.

What this means:

In neurodivergent adults, there is a strong link between joint hypermobility, dysautonomia, and pain. Increased awareness and understanding of this association may enhance the management of symptoms and allied difficulties in neurodivergent people, including co-occurring physical symptoms, and guide service delivery in the future. It highlights the importance of screening for hypermobility in neurodivergence and vice versa but also the importance of making health care services more accessible. We are conducting further research in this area

Read the full study: https://www.frontiersin.org/articles/10.3389/fpsyt.2021.786916/full

Huge thanks to all the team:

Jenny LL Csecs (1,2), Valeria Iodice (3,4), Charlotte L Rae (5), Alice Brooke (2), Rebecca Simmons (2), Lisa Quadt (1, 2), Georgia K Savage (1, 2) Nicholas G Dowell1, Fenella Prowse (1,7), Kristy Themelis (1,5), Christopher J Mathias (3,4,8), Hugo D Critchley (1,2), Jessica A Eccles (1,2)

1. Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom

2. Research and Development, Sussex Partnership NHS Foundation Trust, Sussex, United Kingdom

3. Autonomic Unit, National Hospital for Neurology and Neurosurgery, London, United Kingdom

4. Faculty of Brain Sciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom

5. School of Psychology, University of Sussex, Brighton, United Kingdom

6. Neurodevelopmental Service, Sussex Partnership NHS Foundation Trust, Sussex, United Kingdom

7. Centre for Regenerative Medicine and Devices, University of Brighton, Brighton, United Kingdom

8. Department of Medicine, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom