Developmental Disability

Developmental disability is an “umbrella term” covering a wide range of disabilities and conditions where a disability becomes evident over the developmental years, usually before age 8, but always before adulthood.

It is called ‘developmental’ because often development of skills and/or physical/body parts such as muscles, develop at a slower rate than for other children. Developmental disability can be caused by a genetic condition, illness or accident or the cause may be unknown. For many people, their developmental disability occurs before or at birth, or it could be acquired before age 18. Developmental disability affects the person over their whole lifetime.

How it affects people

Developmental disability can affect people’s abilities in physical skills, learning, processing information, communicating and socialising. Developmental disability affects each person differently and to different degrees, depending on many factors including the cause of the disability, family life, education opportunities, support systems and environmental factors. People may need assistance with everyday activities such as mobility, small hand movements, learning at school, household tasks, organising daily activities, engaging socially with others and managing money. It may mean that people take longer to learn skills and gain knowledge or may need some specific supports, e.g. visual or hearing aids, for physical movement such as splints and other aids, communication aids and therapies which may support development of particular skills such as sitting, walking, using a pencil or spoon, eating, drinking and talking. Some people may need supports in their environment such as regular routines, more specific explanations and support with how to do things or organise their lives. Some people with developmental disability live fairly independently with supports from family and friends, whilst other people may need help with many aspects of their lives.

Specific conditions

Developmental disability may be obvious from birth or may be detected in the early childhood years by parents, teachers, or other professionals. Because ‘developmental disability’ includes a range of more specific diagnoses, some of which are listed below, people are best to learn about those specific conditions. Where a person’s development is affected across many areas of life – physical, communication, learning, daily living and social skills, the term ‘global developmental delay’ is often used.

  • Angelman Syndrome
  • Attention-Deficit/Hyperactivity Disorder
  • Autism Spectrum Disorder
  • Cerebral Palsy
  • Down Syndrome
  • Fetal Alcohol Spectrum Disorder
  • Fragile X Syndrome
  • Hearing Loss
  • Intellectual Disability
  • Language and Speech Disorders
  • Learning Disorders
  • Muscular Dystrophy
  • Prader -Willi Syndrome
  • Rett Syndrome
  • Tourette Syndrome
  • Vision Impairment

Some people with developmental disability may also have “behaviours of concern” or “challenging behaviour” including behaviours where they harm themselves or be verbally or physically aggressive. These behaviours are usually a communication to others that the person is in need – of pain relief, reassurance, to feel safer, to feel secure in what is going to happen or what is happening or maybe an expression of frustration. or need for attention. A behaviour support practitioner, psychologist, speech pathologist or occupational therapist may provide advice on communication and support to assist people with disability to be more easily able to communicate their needs and for family members and other to be able to support the person in ways which are helpful to them.


A young man with Downs syndrome drinking tea with a friend