Beyond bendy joints: number of variant connective tissue features predicts neurodivergent characteristics in hypermobile individuals with anxiety

The goal of this study was to determine whether the number of connective tissue features in hypermobility is associated with level of neurodivergent characteristics and establish whether autonomic reactivity is a mechanistic factor in the relationship between variant connective tissue and neurodivergent characteristics. 99 adult participants were assessed for joint hypermobility syndrome/hypermobile Ehlers-Danlos-Syndrome and filled out screening questionnaires for autism and ADHD. 99% of participants met criteria for generalized joint hypermobility, and 57% for hypermobile Ehlers-Danlos-Syndrome. 47% of participants scored above screening threshold for autism and 20% for ADHD. All measures were significantly correlated. Level of autonomic reactivity (as measured by the Body Perception Questionnaire) mediated the relationship between number of connective tissue features and neurodivergence, even after controlling for anxiety level. This shows that autonomic reactivity has a potential mechanistic role in the established link between variant connective tissue and neurodivergence, opening novel pathways for research and clinical care.