Open research questions in Down syndrome and intellectual disability research

What the literature leaves open

• Studies have been limited by small and selected samples. The role of early life trauma in the associations is unknown.

  Psychotic experiences and disorders in adolescents and young adults with borderline intellectual functioning and intellectual disabilities: evidence from a population-based birth cohort in the United Kingdom · 2025 · DOI

• Down syndrome (DS), caused by trisomy of chromosome 21, is the leading genetic cause of intellectual disability, yet the mechanisms disrupting fetal brain development remain unclear.

  Single-cell atlas of the developing Down syndrome brain cortex · 2026 · DOI

• There is limited evidence from Sweden, a country with distinct educational and support frameworks for youth with ID.

  Sedentary behaviour and physical activity levels in Swedish adolescents with and without intellectual disabilities · 2026 · DOI

• CONCLUSIONS: Although there is a growing effort to include children with disabilities in well-being research, a consensus on a comprehensive well-being self-report measure is lacking.

  Mapping the Instruments Used to Measure Well‐Being on Children With Disabilities: A Scoping Review · 2025 · DOI

• Keyes' MHC-SF remains the most global proposal integrating eudemonic and hedonic aspects of well-being but has not been validated in children with disabilities.

  Mapping the Instruments Used to Measure Well‐Being on Children With Disabilities: A Scoping Review · 2025 · DOI

• Future research should explore interventions aimed at improving parental HL and examine the extent to which these efforts translate into improved health outcomes for people with DS.

  Metabolic, Hematological, and Functional Health in Adults with Down Syndrome and Significance of Parental Health Literacy: A Cross-Sectional Study · 2025 · DOI

• DS is associated with impaired cellular responses to oxidative stress and hypoxia; however, these abnormalities have not been explored in trisomy 21 (TS21) airway epithelial cells (AECs) during RSV infection.

  Impaired airway epithelial miR-155/BACH1/NRF2 axis and hypoxia gene expression during RSV infection in children with down syndrome · 2025 · DOI

• Knowledge regarding the prevalence, associations and development of these physical health conditions could be used for purposes of prevention as well as appropriate care and support but is currently lacking.

  Physical health conditions in young children with profound intellectual and multiple disabilities: The prevalence and associations between these conditions · 2024 · DOI

• In addition, specific guidelines for the management of metabolic issues along the challenging period of transitioning from pediatric to adult health care are lacking.

  Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life · 2024 · DOI

• DISCUSSION: Currently available literature shows limited information on aging in RGNDs, with relatively many reports of young-onset dementia.

  Dementia in Rare Genetic Neurodevelopmental Disorders · 2024 · DOI

• However, little is known about dementia in rare genetic neurodevelopmental disorders (RGNDs).

  Dementia in Rare Genetic Neurodevelopmental Disorders · 2024 · DOI

• However, currently there is limited information available, regarding the suicidal behaviour of this group in Bangladesh.

  Self-reported suicidal behaviour among people living with disabilities: prevalence and associated factors from a cross-sectional nation-wide survey in Bangladesh · 2024 · DOI

• However, the extent of physical activity's impact on the cognitive functioning of this population remains insufficiently explored.

  The effect of the Bilateral Integration exercise program on the cognitive functioning of pupils with moderate intellectual disabilities · 2024 · DOI

• Rigorous evaluation of the performance of Kidslife and Kidslife Down in clinical settings is necessary, or the development of new instruments tailored for children with DS is warranted to comprehensively assess quality of life in clinical settings.

  Instruments for the assessment of quality of life in children and adolescents with Down syndrome: a scoping review · 2024 · DOI

• Conclusion There is limited information available regarding the psychometric properties of instruments used to assess quality of life, particularly health-related quality of life.

  Instruments for the assessment of quality of life in children and adolescents with Down syndrome: a scoping review · 2024 · DOI

• Importance: Small, geographically limited studies report that people with intellectual and developmental disabilities (IDD) have increased risk for serious pregnancy-related and birth-related challenges, including preeclampsia, preterm birth, and increased anxiety and depression, than their peers.

  Perinatal and Postpartum Health Among People With Intellectual and Developmental Disabilities · 2024 · DOI

• The study had a small sample size of seven families. The study was limited to families of children enrolled at the participating day-treatment center. The study relied on parent reports and case files, which may be subject to bias.

  Adversity and Resilience in Children With Moderate-to-profound Intellectual Disabilities: A Multi-source, Multiple-case Study Across Developmental Stages · 2026 · DOI

• Future research should examine the long-term effects of adversity on children with intellectual disabilities. Future research should investigate the effectiveness of interventions aimed at promoting resilience in this population.

  Adversity and Resilience in Children With Moderate-to-profound Intellectual Disabilities: A Multi-source, Multiple-case Study Across Developmental Stages · 2026 · DOI

• The study faced challenges in terms of small sample size and limited control over potential confounding variables. The study had to address the complexity of examining the relationship between circadian rest-activity rhythms and cognitive function in adults with Down syndrome.

  Circadian Rest-Activity Rhythms, Cognition, and Alzheimer Disease Dementia in Adults With Down Syndrome · 2026 · DOI

• There is a lack of research on the role of circadian rhythm disruption in Alzheimer's disease-related cognitive impairments in adults with Down syndrome. The study aims to address this gap by examining the association between the 24-hour rest-activity rhythm and cognition, dementia symptoms, and clinical Alzheimer's disease status in adults with Down syndrome.

  Circadian Rest-Activity Rhythms, Cognition, and Alzheimer Disease Dementia in Adults With Down Syndrome · 2026 · DOI

• Future research should focus on developing strategies for radical inclusion. Future research should investigate the experiences of individuals with I/DD and their families in healthcare transition.

  Structural Ableism and Healthcare Transition for Adults with Intellectual and/or Developmental Disabilities · 2026 · DOI

• The gap is the lack of understanding of structural ableism in healthcare transition. The gap is the exclusion of individuals with I/DD from healthcare services.

  Structural Ableism and Healthcare Transition for Adults with Intellectual and/or Developmental Disabilities · 2026 · DOI

• The study only included a small number of observed video consultations. The study only included semistructured interviews with a limited number of participants.

  Virtual Consultations for People With Intellectual Disabilities in General Practice and Community Care: Mixed Methods Qualitative Study · 2026 · DOI

• Research should be conducted to determine how delays in recognising illness in adults with a severe or profound learning disability can be minimised. Research should aim to better understand the reasons for avoidable deaths due to treatable causes in individuals with a severe or profound learning disability.

  Virtual Consultations for People With Intellectual Disabilities in General Practice and Community Care: Mixed Methods Qualitative Study · 2026 · DOI

• The need for adaptations to be made to existing interventions for use with adolescents with intellectual disabilities. The importance of increasing engagement and understanding in this population. The challenge of delivering interventions to individuals with intellectual disabilities.

  Adaptation of behavioural activation for adolescents with mild to moderate intellectual disabilities and depression · 2026 · DOI

Most-cited papers in Down syndrome and intellectual disability research

• Developing the World Health Organization Disability Assessment Schedule 2.0 · Bulletin of the World Health Organization · 2010 · 1,526 citations
• Prevalence of intellectual disability: A meta-analysis of population-based studies · Research in Developmental Disabilities · 2011 · 1,452 citations
• Trends in the Prevalence of Developmental Disabilities in US Children, 1997–2008 · PEDIATRICS · 2011 · 1,361 citations
• Mental ill-health in adults with intellectual disabilities: prevalence and associated factors · The British Journal of Psychiatry · 2006 · 1,047 citations
• Down's syndrome · The Lancet · 2003 · 959 citations
• Persons With Disabilities as an Unrecognized Health Disparity Population · American Journal of Public Health · 2015 · 927 citations
• Prevalence of Disabilities and Health Care Access by Disability Status and Type Among Adults — United States, 2016 · MMWR Morbidity and Mortality Weekly Report · 2018 · 725 citations
• The ‘F‐words’ in childhood disability: I swear this is how we should think! · Child Care Health and Development · 2011 · 589 citations
• Defining social inclusion of people with intellectual and developmental disabilities: An ecological model of social networks and community participation · Research in Developmental Disabilities · 2014 · 454 citations
• The Neurodiversity Approach(es): What Are They and What Do They Mean for Researchers? · Human Development · 2022 · 441 citations

Most recent work

• Accessibility and responsiveness of Better Access treatment services: Insights from the use of linked administrative data in the evaluation of Better Access · Australian & New Zealand Journal of Psychiatry · 2026
• Single-cell atlas of the developing Down syndrome brain cortex · Nature Medicine · 2026
• Molecular and cellular processes disrupted in the early postnatal Down syndrome prefrontal cortex · Science · 2026
• Caregiver-Reported Attainment of Developmental Skills in Down Syndrome · PEDIATRICS · 2026
• Factors Associated With the Receipt of Female Breast Cancer Treatment Among People Living With Intellectual or Developmental Disabilities: A Population‐Based Retrospective Cohort Study · Journal of Intellectual Disability Research · 2026
• Addictive behaviors among people with intellectual disability: An umbrella review · Clinical Psychology Review · 2026
• Sedentary behaviour and physical activity levels in Swedish adolescents with and without intellectual disabilities · BMC Pediatrics · 2026
• Blinded by the dollar, neglecting people’s care. Commentary on “Federal Court cases about harm to people with intellectual disabilities in service provision” (Hough et al., 2026) · Research and Practice in Intellectual and Developmental Disabilities · 2026
• Circadian Rest-Activity Rhythms, Cognition, and Alzheimer Disease Dementia in Adults With Down Syndrome · Neurology · 2026
• Promoting healthy behaviours in young people with intellectual disabilities: a pilot RCT of an mHealth-based intervention targeting physical activity and sedentary behaviour · Disability and Rehabilitation Assistive Technology · 2026

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