Global developmental delay and autism are two different things, although they can look similar in young children and some children have both. Global developmental delay describes a young child who is well behind in several areas of development. Autism is a lifelong neurodevelopmental difference that shapes how a person communicates, relates to others and experiences the world.
What is global developmental delay?
Global developmental delay (GDD) is a term used when a child under five is significantly delayed in two or more areas of development. These areas usually include:
- Gross and fine motor skills, such as walking, climbing or using their hands
- Speech and language
- Thinking and learning
- Social and emotional skills
- Everyday skills, such as feeding, dressing and toileting
GDD isn’t very common. The same research estimates it affects around 1 to 3% of preschool children.
GDD is a description of where a child is right now, not a final answer about why. Children with GDD are usually reassessed as they get older. Some catch up with the right support. Others later receive a more specific diagnosis, such as intellectual disability or autism.
What is autism?
Autism is a neurodevelopmental difference that affects social communication and interaction, along with restricted interests and repetitive patterns of behaviour. It’s lifelong. Autistic people can learn and develop throughout their lives, but autism itself doesn’t go away.
In Australia, autism is diagnosed with a support level from 1 to 3, depending on how much support a person needs in daily life. You can read more in our guide to Level 2 Autism in Australia.
How are they different?
The simplest way to think about it is that GDD is about pace, and autism is about pattern. A child with GDD is developing more slowly than expected across several areas. An autistic child is developing differently, particularly in how they communicate, connect and respond to their environment, and they may or may not also have delays.
| Global developmental delay | Autism | |
|---|---|---|
| What it describes | Significant delay in two or more areas of development | A different pattern in social communication, interests and behaviour |
| Age | Used for children under five | Can be diagnosed at any age |
| Over time | Often reassessed; some children catch up, others get a more specific diagnosis | Lifelong |
| Can it occur with the other? | Yes | Yes |
Why they can look alike
In the early years, the two can overlap a lot. Both can involve late talking, limited play, not responding to their name, or finding daily routines hard. Researchers note that many children with GDD show some autism-like traits without meeting the criteria for autism, which is why telling them apart in preschoolers can be difficult.
This is also why some children are first described as having developmental delay, and then diagnosed as autistic later, once their development becomes clearer. A diagnosis should always come from a paediatrician, psychologist or multidisciplinary team after a proper assessment.
Can a child have both?
Yes. A child can be autistic and also have global developmental delay. When that happens, support needs to address both the delays across different areas and the child’s autistic way of communicating and experiencing the world.
How does the NDIS treat them?
Both can lead to NDIS support, but through slightly different routes. Children younger than 6 with developmental delay may be eligible under the NDIS early intervention requirements, even without a specific diagnosis. Autistic children and adults may be eligible under the disability requirements, the early intervention requirements, or both, depending on the evidence of how autism affects their daily life.
There’s also an important change for young children. From 1 October 2026, children aged 8 and under with developmental delay and/or autism and low to moderate support needs start to access support through Thriving Kids, a new program outside the NDIS. Children with high support needs remain eligible for the NDIS. Our guide to NDIS plans explains how funding works once a child is on the scheme.
What support helps?
Support should be based on what the child needs, not just the label. For many young children with either GDD or autism, that includes early childhood intervention, often with a key worker who coordinates therapy and works with the family.
ABA therapy can help build everyday skills such as communication, play, self-care and following routines. When behaviour is making daily life hard, Positive Behaviour Support looks at why it’s happening and what can help.
When to seek advice
If you’ve noticed your child is behind in more than one area, or you’ve seen early signs of autism, talk to your GP, paediatrician or Maternal and Child Health nurse. Getting an assessment early means support can start sooner, whatever the outcome.
Getting started with Helping Hands Behaviour Support
Helping Hands Behaviour Support (HHBS) is an NDIS-registered provider delivering Positive Behaviour Support, ABA therapy and early childhood intervention across Melbourne. We work with children and adults at home or at school. As a registered provider, we can work with NDIA-managed, plan-managed and self-managed plans.
If you’re a participant, parent or carer, call us on 0406 920 296 or get in touch through our contact page, and we’ll help you get the right support in place. If you’re a support coordinator, you can make a referral online.
NoteL: This article is general information, not a diagnosis or assessment of any child. Only a qualified health professional can diagnose global developmental delay or autism.
