The Relationship Between Fibromyalgia and Neurodivergent Traits Is Partially Mediated by Hypermobility: A Self-Selected Population Based Survey

INTRODUCTION Chronic musculoskeletal pain is now a common feature among younger women. Many such women exhibit a range of additional physical and psychological features and fulfil criteria for fibromyalgia. Hypermobility, irritable bowel syndrome and migraine are frequent comorbid conditions. These are all in part mediated by dysfunction of the autonomic nervous system and commonly include fatigue, poor sleep and brain fog. Anxiety, social withdrawal and a range of autistic traits are frequently described by those with chronic musculoskeletal pain, and autistic people are over-represented among patients attending pain clinics. This study was designed to explore the correlation between the degree of pain and autistic traits described within a self-selected community-based population. METHODS The study used a nonexperimental, correlational design with data collected from a volunteer sample of 448 adults (aged 18-60) who completed online self-report questionnaires assessing each of autistic traits (RAADS score), fibromyalgia symptoms (ACR criteria) and hypermobility (Beighton’s test). Correlation analysis and linear regressions were used to test the relationships between each disorder. Data was analysed using parametric and non-parametric techniques to assess prevalence, strength and significance of relationships, causes of variance within populations and mediations. RESULTS Our self-selected community population had a mean age of 24 years and was 77% female. The prevalence of significant autistic traits, fibromyalgia and hypermobility were all much greater than expected at 65%, 40% and 44% respectively. Those identifying as non-binary or trans had the highest rates. Fibromyalgia was significantly associated with autistic traits, with dysautonomia a stronger predictor than chronic pain. Regression analyses revealed hypermobility partially mediated the relationship between autistic traits and fibromyalgia. DISCUSSION This is the first community study to provide evidence for a direct association between fibromyalgia and neurodivergent traits. Although self-selected, the findings in our predominantly young population confirm that these conditions are common and that those with autistic traits are at significantly increased risk of developing fibromyalgia, especially if they are hypermobile.