Autism criteria and levels of support
Written by:
Leah Izenberg, BEd, MEd
| August 2025
Criteria for diagnosing Autism
Autism is characterized by differences in social communication and interaction, along with the presence of restricted or repetitive patterns of behaviour, interests, or activities. These differences can affect everyday functioning but may not always be obvious to others.
Autism is formally recognized in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). To receive a diagnosis, an individual must meet specific criteria across two areas:
- Social communication and interaction
- Restricted and repetitive behaviours or interests
To receive a diagnosis of Autism, a person must show differences in both of the following core areas:
- Social communication and interaction, which may include:
- Difficulty with back-and-forth conversation or sharing interests and emotions
- Challenges interpreting social cues like facial expressions, tone of voice, or body language
- Differences in developing and maintaining relationships, such as struggling with peer interactions or adjusting to social expectations
- Restricted and repetitive behaviours or interests, such as:
- Repetitive movements (e.g., hand-flapping, rocking) or repeated use of objects or language
- A strong need for routines or resistance to change
- Intense interests or deep focus on specific topics or objects
- Sensory differences, such as being highly sensitive—or under-sensitive—to sounds, lights, textures, smells, or other sensory input
These traits must be present in early development, though they may not always be obvious at first. Some children may mask their differences or develop coping strategies that delay identification (APA, 2022).
In addition to these core areas, many autistic individuals experience challenges related to executive functioning—the mental skills that help us manage our emotions, behaviour, and attention. Skills like emotional regulation, cognitive flexibility, and impulse control can be harder to access, especially during transitions, changes in routine, or moments of sensory overload (Guazzo & Ginolfi, 2025).
Autism levels of support
The DSM-5 also describes three levels of support—Level 1 (requiring support), Level 2 (requiring substantial support), and Level 3 (requiring very substantial support). These levels are assigned separately for two areas: social communication and restricted, repetitive behaviours. This means a person might be rated as Level 1 in one domain and Level 2 or 3 in another, depending on the amount of support they require in each area.
The levels are based on several factors:
- How much support the individual needs to function in daily life
- The impact of their differences across settings (e.g., home, school, community)
- The intensity and frequency of traits (such as difficulty with flexibility, distress at changes, or challenges with interaction)
It’s important to remember that these levels of support are general guidelines. They do not capture the full complexity of an individual’s strengths, needs, or how support requirements may shift over time or in different environments.
Some autistic advocates have shared that levels of support are not helpful ways to talk about their unique profile of strengths and needs and instead, prefer to discuss specific areas of support (e.g., my child benefits from support when meeting new people or in loud environments, but only needs support occasionally with getting dressed in the morning).
See the National Autistic Society for further details.
