To Örebro University

BACKGROUND: The conventional way to identify generalised joint hypermobility is by a physical examination according to the Beighton Score. However, a physical examination is time-consuming in clinical practise and may be unfeasible in population-based studies. The self-assessment five-part questionnaire on hypermobility (5PQ) offers a more practicable way to identify GJH. The aim of this study was to test validity and reliability of the five-part questionnaire on hypermobility (5PQ) translated into Swedish on a non-clinical adult population.

METHODS: A structured procedure was used for the translation of the 5PQ into Swedish. The Beighton Score was used as reference standard for generalised joint hypermobility. Test-retest reliability was tested in a separate group who filled in the questionnaire twice with a ten-week interval. Participants consisted of a convenience sample recruited in Stockholm, Sweden (2017).

RESULTS: A total of 328 participants were included in the study, 297 participants in the validity group and 31 participants in the reliability group. When evaluated against a present Beighton Score with an age-dependent cut-off, the Swedish 5PQ attained a sensitivity of 91%, a specificity of 75% and an area under the curve of 0.87. The Swedish 5PQ showed substantial to almost perfect test-retest reliability.

CONCLUSIONS: The Swedish 5PQ is a valid and reliable instrument to screen for or to identify generalised joint hypermobility.

Growing evidence suggests an unexpected association between generalised joint hypermobility (GJH) and several psychiatric conditions, and a shared pathophysiology has been proposed. No previous studies on adult attention-deficit/hyperactivity disorder (ADHD) are available. This study aimed to evaluate the association between adult ADHD and GJH. A total of 431 adults with ADHD and 417 non-ADHD controls were included in this cross-sectional comparative study. GJH was assessed by physical examination following the Beighton scoring system (BSS). Furthermore, musculoskeletal symptoms and skin abnormalities were queried to create a proxy for symptomatic GJH (e.g., Hypermobility spectrum disorders and Ehlers-Danlos syndrome) to differentiate this from non-specified GJH defined by BSS only. Logistic regression examined the influence of ADHD and candidate covariates (age, sex, ethnicity) on GJH and symptomatic GJH, respectively. ADHD was significantly associated with GJH, as defined by the BSS, with adjusted odds ratios of 4.7 (95% confidence interval [CI] 3.0-7.2, p < .005). Likewise, ADHD was significantly associated with symptomatic GJH, as defined by the BSS and additional symptoms, with adjusted odds ratios of 6.9 (CI 95% 4.1-11.9, p < .005). Our results suggest that GJH may represent a marker for an underlying systemic disorder involving both connective tissue and the central nervous system. GJH with additional musculoskeletal symptoms and/or skin abnormalities has a considerable stronger link to adult ADHD than non-specified GJH has, and may need awareness in ADHD management. Future studies should investigate the mechanisms behind this association and how comorbid GJH affects ADHD outcome.

Autism spectrum disorder (ASD) and generalised joint hypermobility (GJH) share a number of clinical manifestations including proprioceptive impairment, motor difficulties, sensory hypersensitivity, and autonomic dysfunction. Clinical observations suggest that GJH is overrepresented in ASD. However, there are currently few systematic studies available. Knowledge about comorbidities may unfold common aetiopathological pathways underlying the association and improve the clinical management. The aim of this large, cross-sectional comparative study is to evaluate the relationship between ASD and GJH in adults. Data on joint hypermobility, symptoms associated with both hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS), lifetime psychiatric diagnoses, psychiatric rating scales for ASD and attention deficit hyperactivity disorder (ADHD), and socio-demographics was collected for 199 individuals with ASD and 419 non-ASD community controls. Logistic regression models adjusting for covariates (age, sex, ethnicity) revealed a significant relationship between ASD and GJH and between ASD and symptomatic GJH, with adjusted odds ratios of 3.1 (95% CI: 1.9, 5.2; p < 0.001) and 4.9 (95% CI: 2.6, 9.0; p < 0.001), respectively. However, the high prevalence of comorbid ADHD in the study sample reduces the generalizability of the results among individuals with ASD without comorbid ADHD. Possibly, an additional ADHD phenotype is the primary driver of the association between ASD and GJH. Furthermore, GJH with additional self-reported symptoms, suggestive of HSD/hEDS, showed a stronger association with ASD than did non-specified GJH, indicating that symptomatic GJH plays a greater role in the relationship than non-specified GJH does. Therefore, the current study underscores the need of careful sample subclassifications. ASD with GJH may represent a novel subgroup of ASD in terms of aetiopathology and clinical presentation. Future research should elucidate the aetiological factors behind the association between ASD and GJH and evaluate how the comorbidity of GJH affects ASD outcomes.

BACKGROUND: Generalised joint hypermobility (GJH) is reportedly overrepresented among clinical cases of attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and developmental coordination disorder (DCD). It is unknown if these associations are dimensional and, therefore, also relevant among non-clinical populations.

AIMS: To investigate if GJH correlates with sub-syndromal neurodevelopmental symptoms in a normal population.

METHOD: Hakim-Grahame's 5-part questionnaire (5PQ) on GJH, neuropsychiatric screening scales measuring ADHD and ASD traits, and a DCD-related question concerning clumsiness were distributed to a non-clinical, adult, Swedish population (n=1039).

RESULTS: In total, 887 individuals met our entry criteria. We found no associations between GJH and sub-syndromal symptoms of ADHD, ASD or DCD.

CONCLUSIONS: Although GJH is overrepresented in clinical cases with neurodevelopmental disorders, such an association seems absent in a normal population. Thus, if GJH serves as a biomarker cutting across diagnostic boundaries, this association is presumably limited to clinical populations.