
Our Director and Clinical Lead, Jo Condon, has written this blog to help parents understand the levels of autism.
What are the levels of autism?
The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is recognised in much of the world as the authoritative guide to the diagnosis of mental health issues and neurodevelopmental conditions.
The DSM-5 outlines the diagnostic criteria for autism, and individuals must meet these diagnostic criteria in order to be diagnosed with autism spectrum disorder.
In addition to the diagnostic criteria, the DSM-5 also specifies ‘severity levels’ of autism. Severity levels relate to the amount of support an autistic child requires in comparison to their neurotypical peers. Severity levels are assigned to two areas of functioning in autistic children:
- Social communication
- Restricted, Repetitive Behaviours
What is the difference between types of autism and levels of autism?
When the fifth edition of the Diagnostic and Statistical Manual was published in 2013, the term ‘Autism Spectrum Disorder’ replaced previous autism related diagnoses, or ‘types of autism’, including:
- Autistic disorder
- Rett’s disorder
- Childhood disintegrative disorder
- Asperger syndrome
- PDD-NOS (pervasive developmental disorder not otherwise specified)
This was a reflection of the broader understanding of the way that autism presents in different individuals. Now, rather than thinking about there being different ‘types’ or ‘subtypes’ of autism, we understand that autism is a spectrum disorder and the way autism impacts a child or adult varies greatly.
The severity specifiers, or levels of autism, provide additional specificity around the child’s symptoms and needs.
Intellectual impairment and autism
Autism is separate from intellectual ability; there is a separate specifier in the DSM-5 which relates to whether the individual has an accompanying intellectual impairment or not.
What impacts an autistic child’s support needs?
There are many factors which impact the level of support an autistic child needs, these include:
Communication: A child with little or no speech is likely to have higher support needs than a verbally fluent child
Social interaction: Children who struggle to interact with others, for example, who show little awareness of others or are unable to ask for help, will need additional support in comparison to children who have some level of interaction
Sensory processing: Children with more severe sensory processing difficulties will require more support in day-to-day living
Information processing: the level of difficulty that a child has with processing information and flexible thinking will impact the level of support they need
What level is ‘high-functioning’ autism
People described as high-functioning have level 1 support needs. However, the term ‘high-functioning’ can be very misleading, so we try not to use it. You can find out why here.
DSM–5 severity levels for autism
Social communication levels
Level 1
Descriptor:
Requiring support
Description:
Without supports in place, deficits in social communication cause noticeable impairments. Difficulties experienced by individuals requiring this level of support may include:
- Difficulty initiating social interactions
- Struggles with responses to the social approaches of others
- Decreased interest in social interaction
- Difficulties making friendships
- Struggling to maintain to-and-fro conversation
Level 2
Descriptor:
Requiring substantial support
Description:
Marked deficits in verbal and non-verbal communication skills.
Difficulties experienced by individuals requiring this level of support may include:
- Unable to use complex language
- Limited initiation of social interaction
- Unusual response to other’s social approaches
- Unusual non-verbal communication
- Limited range of conversational topics
Level 3
Descriptor:
Requiring very substantial support
Description:
Severe deficits in verbal and non-verbal social communication skills cause severe impairments in functioning.
Difficulties experienced by individuals requiring this level of support may include:
- No or limited level of speech
- Rarely shows interest in initiating social interactions
- Minimal social responses
- Most communication and interaction is related to meeting needs
Restricted, repetitive behaviour levels
Level 1
Descriptor:
Requiring support
Description:
Inflexibility of behaviour causes significant interference with functioning in one or more contexts.
Difficulties experienced by individuals requiring this level of support may include:
- Difficulties with changes, preference for same routine but not distressed by this
- Special interests that do not impact on other areas of life
- Difficulties planning and organising
- Repetitive behaviours that are not particularly obvious to others
Level 2
Descriptor:
Requiring substantial support
Description:
Inflexibility of behaviour, difficulty coping with change or other restricted / repetitive behaviour appear frequently enough to be obvious to the casual observer and interfere with functioning in a variety of contexts.
Difficulties experienced by individuals requiring this level of support may include:
- Distress in response to changes in routine
- Special interests impact on other areas of life
- Frequent repetitive motor movements that moderately impact functioning
- Moderate difficulties with unfamiliar people or places
Level 3
Descriptor:
Requiring very substantial support
Description:
Inflexibility of behaviour, extreme difficulty coping with change or other restricted / repetitive behaviour markedly interfere with functioning in all spheres.
Difficulties experienced by individuals requiring this level of support may include:
- Extreme distress in response to changes
- Frequent repetitive motor movements that significantly impact functioning
- Repetitive behaviours cause self-injury
- Unable to cope with unfamiliar people or places
Can the severity level of a child’s autism change with time?
Yes, the severity level of a child’s autism can change as they develop skills and abilities.
However, future severity levels are not something that can be predicted.
Not all children follow a predictable developmental trajectory. Some non-speaking children develop speech later in life, and as a result, their support needs change significantly. The impact of restricted and repetitive behaviours can also decrease with age.
Research shows that early identification and intervention can improve longer-term outcomes for autistic children. It is therefore important to access an autism assessment as soon as you notice autism signs or characteristics.
How we can help
We are a specialist autism service providing private autism assessments for children aged 2 years and above. If you are concerned that your child is showing signs of autism, contact us to discuss whether an autism assessment would be beneficial.
We have a friendly, professional team who are able to screen for signs of autism at no cost.



