By Jenny LL Csecs1,2†, Valeria Iodice3,4†, Charlotte L Rae5, Alice Brooke2, Rebecca Simmons2, Lisa Quadt1, 2, Georgia K Savage1, 2 Nicholas G Dowell1, Fenella Prowse1,7, Kristy Themelis1,5, Christopher J Mathias Hugo D Critchley1,2, Jessica A Eccles*1,2
What are neurodivergent conditions?
Neurodivergent conditions include autism, attention deficit hyperactivity disorder (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 with both strengths and difficulties.
Led by the Brighton and Sussex Medical School (BSMS) and funded by the MRC, MQ Mental Health Research and Versus Arthritis, this research into the relationship between neurodivergent conditions and hypermobility found that more than 50% of participants with a diagnosis of Autism, 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 (e.g., dizziness on standing up) than the comparison group, and this was related to the number of hypermobile joints.
Dr Jessica Eccles, Lead Author and Clinical Senior Lecturer and MQ Versus Arthritis Fellow at BSMS, said: “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.
“Health providers need to make improvements to their services and 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 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 the 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.
Autism, ADHD, and tic disorder (Tourette syndrome) 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 on 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 the link between autism/ADHD and hypermobility/Ehlers Danlos Syndrome (EDS) clear. 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.
Generalized joint hypermobility (GJH, henceforth hypermobility) was determined by physical examination incorporating the Beighton scale in adults with a formal diagnosis of neurodevelopmental conditions (the neurodivergent group, n = 109) and were compared to those in the general population in the UK. This measure uses a Beighton scale cut-off of 4 in line with the older Beighton 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 (n = 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 GJH as described by the hypermobility EDS (hEDS) 2017 criteria.
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 levels of hypermobility was 28.4%, more than double than the comparison group (12.5%). There were interesting differences between males and females. Statistical analyses suggest 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 a cut-off of 4 on the Beighton Scale) for the different neurodivergent groups in contrast to the comparison group. The lines (error bars) indicate how precise we can be about the results.
The chart below demonstrates the same findings but using the hEDS age specific cut-off for GJH.
Link with physical symptoms
Neurodivergent participants reported significantly more symptoms of orthostatic intolerance (symptoms related to standing up), and these symptoms tracked with the number of hypermobile joints, as you can see from the chart below:
Neurodivergent participants reported significantly more musculoskeletal symptoms and these symptoms tracked with the number of hypermobile joints, as you can see from the chart below:
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.
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.
1 Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
2 Sussex Partnership NHS Foundation Trust, Sussex, UK
3 Autonomic Unit, National Hospital for Neurology and Neurosurgery, Queens Square, London, UK
4 UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, UK
5 School of Psychology, University of Sussex, Brighton, UK
6 Department of Psychology, University of Warwick, Coventry, UK
7 Guy’s and St Thomas’ NHS Foundation Trust, London, UK
8 Neurovascular Medicine (Pickering Unit), St Mary's Hospital, Imperial College London, London UK