Understanding the different levels of autism

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Someone with autism may experience social communication issues and repetitive patterns of behaviour, generally these can be broken up into three levels of severity. 

Key Points:

  • Autism can be diagnosed in three different levels
  • Each level of autism has unique characteristics
  • The types of support required may vary from level to level as well as person to person

What is autism and how are the levels diagnosed?

Autism is a complex spectrum disorder that can cause social and behavioural problems. It is considered to be a spectrum disorder as it is experienced differently for each person.

Someone with autism may experience social communication issues and repetitive patterns of behaviour.

According to the NDIS autism should be diagnosed by “a specialist multi-disciplinary team, paediatrician, psychiatrist or clinical psychologist”.

When diagnosing autism the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is used. The manual highlights the language and criteria for assessing and diagnosing mental disorders.

There are different levels of autism, all requiring different support. When a diagnosis of autism is reached, the level of autism will then be indicated.

To help doctors determine the correct level of autism they consider social communication abilities and restricted, repetitive behaviours.

Level One: Requires support

A diagnosis of level one autism is the least severe diagnosis. People with level one autism may have visible issues with social communication and behaviour. These issues may cause challenges in some settings. These difficulties require some support to overcome.

Someone with level one autism may:

  • Experience difficulty initiating social interactions
  • Experience difficulty understanding the social signals or cues of others
  • Struggle with maintaining the give-and-take of a typical conversation
  • Appear to have decreased interest in social interactions
  • Experience difficulty with making friends
  • Experience difficulty switching between activities
  • Experience problems with organisation and planning
  • Experience problems adapting to changes

Someone diagnosed with level one autism may use support such as behavioural therapy. Behavioural therapy can help develop positive behaviours that might not come naturally to someone with level one autism.

Level two: Requires substantial support

A diagnosis of level two autism is more severe than level one. With level two autism, someone may experience a more obvious lack of social communication (verbal and non-verbal) and behaviours. To improve this, they will require substantial support from support services.

Someone with level two autism may experience:

  • Distress and/or difficulty changing focus or task
  • Significant lack of verbal and nonverbal communication skills
  • Behaviour issues severe enough to interfere with daily function and be evident to an observer
  • Limited initiation of social interactions
  • Reduced or abnormal responses to social interactions
  • Speaking in simple sentences
  • Narrow and specific special interests

Someone diagnosed with level two autism may use support such as occupational therapy. Occupational therapy can help someone develop the skills they need to complete daily task.

Level three: Requires very substantial support

Level three autism is the most severe autism diagnosis. Someone with level three autism may display severe repetitive or restrictive behaviours and difficulty with social communication. Someone with level three autism will require very substantial support services.

Someone with level three autism may:

  • Experience very limited initiation of social interactions
  • Hardly respond or not respond at all to others that try to interact with them socially. They may only do so to ensure immediate needs are met
  • Respond to only very direct social approaches
  • Have limited ability to use verbal or non-verbal communication
  • Have extreme difficulty coping with change
  • Experience restricted/repetitive behaviours that noticeably interfere with functioning
  • Experience great distress/difficulty changing focus or action

Someone with level three autism may use a support service like a speech therapist. A speech therapist will be able to help them communicate.

Finding Support

The above levels of autism are used to measure the severity of autism someone may experience, but it is not a perfect system. Some people may not fit completely, or at all, into one of the three levels.

Autism symptoms may change over time, becoming more or less severe. This can change or impact the level of autism and the supports required for the individual.

The personal circumstances and challenges of the person diagnosed with autism need to be considered when looking for support. They may need a combined team of different supports to work on developing or improving different areas of difficulty.

For more information about testing and the diagnosis of autism, read our article ‘testing and diagnosing autism’. You can also head to our autism resources page for more support.

What are your thoughts about using these levels to diagnose Autism? Leave a comment below.

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Testing and diagnosing autism
Autism Resources page