Prevalence of ADHD and Autism Spectrum Disorder in Children with Hypermobility Spectrum Disorders or Hypermobile Ehlers-Danlos Syndrome: A Retrospective Study

INTRODUCTION: Hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS) are both characterized by generalized hypermobility, in combination with pain, affected proprioception, and pronounced fatigue. Clinical observation indicates that behavioral problems, hyperactivity, and autistic traits are overrepresented in children with those conditions. The purpose of this retrospective study was to establish the prevalence of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) among children with HSD and hEDS treated in our clinic since 2012. SUBJECTS AND METHODS: Since Ehlers-Danlos syndrome (EDS) diagnostic criteria and international classification were changed in 2017, we equate the older diagnosis EDS hypermobility type with the newer hEDS and the older hypermobility syndrome with HSD. A registry search from the computerized medical record system found 201 children (88 boys, 113 girls) aged 6–18 years who were treated at our pediatrics department with the diagnoses HSD or EDS. All medical records (113 with HSD, 88 with EDS) were reviewed, and key symptoms such as fatigue and pain, as well as diagnosis of ADHD/ASD, were recorded. RESULTS: All EDS cases could be classified as hEDS. Of the entire study cohort, 16% had a verified ADHD diagnosis and a further 7% were undergoing ADHD diagnostic investigation. Significantly more children with hEDS had ADHD compared to children with HSD (p=0.02). In the age group 15–16 years, 35% of those with hEDS had ADHD and, among those aged 17–18 years, ADHD was present in 46%. Children with coexisting ADHD showed a significantly higher proportion of associated symptoms such as fatigue, sleep-problems, and urinary tract problems. ASD had been verified in 6% of the children. Of those with ASD, 92% had sleep problems. CONCLUSION: This study shows a strong association between HSD or hEDS and ADHD or ASD. Therefore, children with HSD or hEDS may need to be routinely screened for neuropsychiatric symptoms.