What do we know about Developmental Disabilities and Its Associated Conditions

By Asst/P Dutt Anuradha
Psychology and Child & Human Development Academic Group, NIE, NTU
Published: 1 August 2022





Overview of Developmental Disabilities

According to the Center of Disease Control (CDC), developmental disabilities consist of a spectrum of conditions that affects an individual’s physical, cognitive/learning, communication/language, social, and/or behavioral facets of day-to-day living. These conditions could be identified at birth or at early developmental stages of childhood. Developmental Disabilities is pervasive throughout the individual’s lifetime. Common conditions within the category of developmental disabilities include intellectual disability, autism spectrum disorder (ASD), specific learning disorder (SLD), down syndrome, cerebral palsy, and sensory impairments (i.e., vision and hearing). A key area of deficit observed in individuals with developmental disabilities includes aspects of adaptive behavior. The American Association on Intellectual and Developmental Disabilities (AAIDD) defines adaptive behavior in terms of three areas – conceptual, social, and practical skills. The severity of these conditions depends on the intensity and number of these adaptive behavior facets that are affected as this determines the level of structural supports, accommodations, and interventions from various personal, national, and global stakeholders required to improve the self-sufficiency of individuals with developmental disabilities in their daily functioning.



Figure 1: AAIDD’s framework on Facets of Adaptive Behavior


The International and Singapore Context on Developmental Disabilities

The Global Burden of Disease (GBD) provides a tool to quantify various healthcare concerns including various developmental disabilities (e.g., intellectual disability, ASD, down syndrome etc.). The GBD datasets are the most comprehensive and current effort to measure epidemiological levels and trends of various healthcare conditions worldwide. Global research teams that specialize on analyzing GBD datasets have provided global prevalence rates and trends for a few developmental disabilities. For instance, Olusanya et al. (2020) have suggested that prevalence rates based on their analysis of the 2017 GBD data for four major developmental disability conditions (including childhood epilepsy, vision and hearing loss, and intellectual disability) have been on the rise, globally, for children under the age of 15 years in the recent years. This increase in prevalence over the recent years seemed pronounced in countries from South Asia and Sub-Saharan Africa.

Similar efforts have been made by a research team in the National Institute of Education (NIE), Nanyang Technological University (NTU), Singapore, led by Mo Chen, PhD, Anuradha Dutt, PhD, and Rahul Nair, PhD (MOE-DEV 05/19 CM), with international collaborators from the US, China, and Australia. Our analysis of the 2019 GBD data suggests that global prevalence for individuals with intellectual disability across the lifespan stands between 1-2% with the highest prevalence in countries such as India. Regional inequalities for prevalence on intellectual disability between developing and developed regions/countries was also a pertinent finding that could be attributed to a lack of resources for early diagnosis, prevention, and intervention. Research efforts from a team in China, Zhen et al. (2021), based on their analysis of the 2019 GBD data for ASD suggests that the global burden for ASD continues to rise especially for developed countries. This could be possible as developed nations are equipped with systemic level supports and resources required for early diagnosis, prevention, and intervention, and awareness/training programs of various stakeholders (e.g., parents, school personnel, medical personnel etc.).

In Singapore, there are about 32,000 students with developmental disabilities (CNA, 2019). Singapore follows a dual educational system consisting of mainstream schools and special education (SPED) schools to better cater to the diverse needs of students with varying degrees of developmental disabilities (Walker, 2016). Thus far, this system has helped provide a structured delivery of accommodations and resources to all children with developmental disabilities. About 80% of these students (or 25,600) have mild degrees of developmental disabilities and are in mainstream schools, including those diagnosed with SLD, mild degrees of ASD, and ADHD based on reports from the Ministry of Education (MOE), Singapore. The remaining 20% (or 6,400), with moderate to severe degrees of developmental disabilities, attend one of 19 special education schools, which are run by a collaborative effort between governmental and social service organisations (CNA, 2019).


Policy and Practice

The United Nations (UN) has proposed Sustainable Developmental Goals (SDG) to direct resources and policy guidelines so that all nations could achieve practice goals to provide equitable provisions for individuals afflicted with disadvantages related to disability, mental health, socio-economic status, gender, etc. by 2030. These goals with reference to individuals with developmental disabilities include equitable provisions for individuals and families that experience poverty, mental health/well-being issues, and lack of accessible educational and vocational opportunities. The SDGs aim to work towards a collaborative partnership of all stakeholders to achieve equitable living opportunities for individuals with developmental disabilities and other afflicted populations.

In Singapore, various governmental organizations via hospitals, schools (special education and mainstream), early childhood centers, and voluntary non-governmental organizations have allocated resources and practice efforts to build independence among individuals with developmental disabilities. These efforts align with UN’s proposed SDGs. For instance, the special education schools’ curriculum proposed by the Ministry of Education, Singapore, articulates the vision of ‘Active in the community, valued in the society' with education outcomes of ‘living, learning and working' for individuals with developmental disabilities. The seven core learning domains of their curriculum include communication/language, literacy/numeracy, daily living skills, social-emotional learning, physical education, arts, and vocational education. Similarly, various government hospitals such as National University Hospital (NUH), KK’s Children’s and Women’s Hospital etc. focus on early identification and intervention for children below 7 years that may experience developmental delays.





Takeaways for Research & Practice

Our research team’s work at NIE in developmental disabilities suggests that –

  • Higher quality evidence on national prevalence rates in Singapore for various categories of developmental disabilities is required to inform allocation of resources based on needs and active living outcomes for individuals and families with developmental disabilities.
  • Tools/scales validated for individuals with developmental disabilities to inform levels of supports and accommodations are needed to help realize equitable and active living goals for this population.
  • Early detection and intervention, and developmental monitoring of young children with developmental disabilities is necessary for the care of individuals in this population across their lifespan.
  • There is a constant need for training programs on evidence-based practices for the care of individuals with developmental disabilities across parents, school personnel, and allied health professionals in areas of socio-emotional, behavioral, educational and communication/language supports for individuals with developmental disabilities.
  • Building a global and national culture of inclusion to promote active and equitable living goals for individuals with developmental disabilities is paramount for reaching healthy outcomes for this population.


Further Research Collaborations

Our research team in NIE – NTU which consists of Anu Dutt, and Mo Chen, are interested to collaborate with international researchers pertaining to improving lives of individuals with developmental disabilities (specifically individuals with intellectual disability). Our research efforts specifically aim towards achieving #IDEAL goals with a focus on the following areas –

  • Scale validation to inform provisions of support/accommodations for individuals with developmental disabilities to achieve active and equitable living outcomes.
  • Analysis of national and global prevalence data on various developmental disabilities.
  • Evaluating the effectiveness of training programs on behavioral and communication/language supports across teachers and allied health professionals for children with developmental disabilities.

If you have any interest in collaboration, please contact Anu Dutt at [email protected]



Chen, M., Dutt, A.S., & Nair, R. (2022). Systematic review of systematic reviews on measures for activities of daily living among children with developmental disabilities. Heliyon. https://doi.org/10.1016/j.heliyon.2022.e09698

Chen, M., Nah, Y-H., Waschl, N., Poon, K., & Chen, P. (2022). Developing and piloting a computerized adaptive test for a culturally appropriate measure of adaptive behavior. Journal of Psychoeducational Assessment, 40(2), 238-254. https://doi.org/10.1177/07342829211047005

Yeong, A. M., & Dutt, A.S., Hong, Y.H., & Nair, R. (2022). The use of self-prompted video modelling on teaching daily-living skills to adolescents with autism spectrum disorder. Journal of Special Education Technology.           https://doi.org/10.1177%2F01626434221102538

Yong, Y.H., Dutt, A., Chen, M., & Yeong, A.M. (2021). Evaluating acquisition, preference and discrimination in requesting skills between picture exchange and iPad®-based speech generating device across preschoolers. Child Language Teaching and Therapy, 37(2), 123-136. https://doi.org/10.1177/0265659021989391

Nair, R., Dutt, A., & Nielson, T. (2020). Brief Report: Psychometric Properties of the Ability in Behavior Assessment and Interventions for Teachers-Revised (ABAIT-R). Journal of Autism and Developmental Disabilities. 50(3), 1081-87. https://doi.org/10.1007/s10803-019-04286-5

Law, G.C., Dutt, A., & Neihart, M.F. (2019). Effectiveness of a mobile app teacher training program to improve functional communication in young children with autism spectrum disorder. Research in Autism Spectrum Disorder, 67. https://doi.org/10.1016/j.rasd.2019.101411



Dutt, A. (2022, August 1). What do we know about Developmental Disabilities and Its Associated Conditions. Child and Human Development, Life@NIE SG®. https://nie.edu.sg/chd/topics/special-education/developmental-disabilities-and-its-associated-conditions