The 3 Levels of Autism Explained

The 3 Levels of Autism Explained

Consideration of a diagnosis of autism for you or your loved one can cause confusion and uneasiness if you’re not familiar with the relevant terminology. Autism spectrum disorder affects how a person behaves, learns, and expresses themselves. Individuals with any diagnosis of ASD may share symptoms in common, yet each person may experience them in a different way and have different strengths and limitations.

The spectrum of autism is divided into three main levels to help people understand the differences of the condition and help doctors prescribe appropriate therapies for the unique needs of their patients. The severity of diagnosis and the level of support an individual may need in their daily life is dependent on whether their diagnosis is level 1, 2 or 3. 

Autism is a diagnosis that tends to carry certain implications. People unfamiliar with autism spectrum disorder may assume that anyone on the spectrum may demonstrate typical behaviours and symptoms, but the truth is there are many different possible signs and symptoms which vary from person to person and guide individualised management and support.

What is Autism?

Autism spectrum disorder (ASD) is a developmental disorder caused by differences in the brain. There are multiple factors that can cause these developmental delays. These include: genetic conditions and environmental factors that act together and change the normal course of human development. People with autism may behave, communicate, interact, and learn in different ways from other people and they may need support in daily living to help them build skills and perform tasks.

What are the three levels of Autism?

Beginning in 2013, rather than specific signs and symptoms of autism, the classification of autism has shifted to reflect the levels of support someone may require within each category.

Level 1

The level 1 ASD classification is the least impactful level on the spectrum. Those classed under this level may require some support to help with issues such as reserved social interaction, as well as lack of organisation and planning skills. These people are most likely to benefit from life skills supports. 

Level 2

The level 2 ASD classification covers the middle range of the spectrum. Those classed under level 2 are likely to require more support, and their symptoms may be more noticeable to others. They may struggle with verbal communication, have restricted interests or challenges in focusing and display frequent and repetitive behaviours.

Level 3

The level 3 ASD classification is the more impactful end of the spectrum and people who fall under this category may require very substantial support. They are likely to present with more severe signs from both levels 1 and 2, while also dealing with other complications. Individuals at this level will have a limited ability to communicate and interact socially, and are likely to have accessibility limitations on most aspects of daily life.

What are the Different Types of Autism?

Prior to the 2013 transition, the levels of autism were explained using terminology that classified people with autism into different phenotypes, or groupings of symptoms, of the disorder, rather than the severity. This caused some misunderstandings and confusion surrounding autism spectrum disorder as it was generally non-specific and open to interpretation. You may have heard of some of the specific terms previously used for autism, which included: 

Asperger’s Syndrome

Asperger’s syndrome described the milder form of Autism or “high functioning”. Although people diagnosed with asperger’s often have fully developed speech and minimal differences from those of neurotypical people, individuals with asperger’s may experience:

  • Difficulty with verbal and non-verbal communication, such as eye contact and sarcasm
  • Lack of interest in social activities or retaining long-term relationships with peers
  • A lack of response to social and emotional experiences
  • A sustained interest in a specific topic, subject or object
  • Repetitive behaviours of movements 

These symptoms may require some level of support but people with asperger’s are unlikely to present any delays in language learning or cognitive development as is the case with more severe levels of autism.

Autistic Disorder

Autistic disorder described the more severe cases of ASD which were often defined by more noticeable troubles with speech and communication, such as an inability to pick up on nonverbal cues including  hand gestures and facial expressions. They may also display repetitive behaviours, experience a delay in language learning and cognitive development, and are more likely to face social challenges that require higher levels of supports.

Pervasive Development Disorder or Not Otherwise Specified (PDD-NOS)

PDD or NOS was diagnosed in people whose symptoms fell somewhere in the middle of the spectrum between Asperger’s and Autistic, and may have required some level of support, though without being considered severe.

Is Autism a Disability?

Autism or autism spectrum disorder is classified as a neurological developmental disability in Australia, and it affects between one to two percent of the worldwide population. The disability is extremely diverse in nature which reflects each individual’s unique experience and level of support needed.

What Causes Autism?

The exact cause of autism is unknown, and the most current research has not identified any single genetic or environmental cause. It is most likely a combination of genetic and environmental influences of which ongoing health research continues to investigate the exact cause. However, there are some known risk factors for ASD which help elucidate its origins:

  • Genetic mutations
  • Fragile X syndrome and other genetic disorders
  • If an immediate family member is also autistic
  • Low birth weight
  • Having older than average parents
  • Metabolic imbalances
  • A history of viral infections

Thankfully, clear and explicit research has shown that there is no linkage between vaccines and autism. A previously controversial study on the topic published in 1998 was discredited, and subsequently retracted, in 2010.

At What Age Does Autism Appear?

Autism spectrum disorder typically develops during early childhood. Some infants may show symptoms of autism within the first 12 months, while other infants may not present with symptoms until after 2 years old. Some children diagnosed with autism may meet developmental milestones and new skills relative to their age until 18 to 24 months, and then stop development of skills or even lose the skills they once had.

What are the Common Signs of Autism?

While autism is frequently characterised by well-known symptoms, understanding how these symptoms may initially present is an important component in early recognition and treatment. Common signs and symptoms include: 

  • Developmental regression, or loss of previously achieved skills or milestones
  • Absence of attention to common objects such as failure to look where you are looking or pointing
  • Abnormal or unexpected reactions to stimuli from their surroundings
  • Abnormal social interactions
  • Absence of smiling when greeted by parents and other familiar people
  • Absence of expected responses to pain or physical injury
  • Language delays or unusual language formulation or structure
  • Repetitive behaviours