The Types and Levels of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a lifelong disability that affects millions of people around the world. It impacts individuals of all races, gender identities, and socio-economic backgrounds. People with autism experience various levels of severity in their condition, characterized by social and communication difficulties, as well as restricted or repetitive patterns of behavior. These levels of autism represent the core traits of the disorder. However, within these traits, individuals can exhibit a wide range of symptoms associated with different types of autism. This variability is why autism spectrum disorder is recognized as a spectrum. Furthermore, to provide a more detailed understanding of how someone experiences their specific type of autism in their daily life, autism is categorized into three distinct levels.




READ MORE: What is Autism?

DSM Categorization of the Types of Autism

The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) is the standard resource used to diagnose mental disorders by healthcare professionals in the United States. The DSM-5 specifically identifies the criteria a person must meet to qualify as having a specific disorder, such as autism spectrum disorder, attention deficit hyperactivity disorder (ADHD), depression, anxiety, and so on. The DSM has been modified over time as it is now in its fifth edition.

DSM-4: Subcategories of Autism Spectrum Disorder

In the DSM-4, autism was divided into five separate diagnoses. More specifically, the DSM-4 included autism within a category of disorders known as Pervasive Developmental Disorders (PDDs). All PDDs in the DSM-4 included Autistic Disorder, Asperger’s Disorder, Rett’s Disorder, Childhood Disintegrative Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS). The DSM-4 considered autism spectrum disorder to include Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder.

DSM-5: No Subcategories of Autism Spectrum Disorder

The DSM-5 was released in 2013. The DSM-5 redefined autism. Autism spectrum disorder is the only classification for autism in the current edition of the DSM. There are no subcategories. However, if someone had an established diagnosis of Asperger’s, Autistic Disorder, or PDD-NOS from the DSM-4, they would likely be considered as having autism spectrum disorder (ASD).

Levels of Autism

According to the DSM-5, autism spectrum disorder (otherwise known as autism) has three levels. A person who is diagnosed with autism will also be labeled as being ASD Level 1, ASD Level 2, or ASD Level 3. The autism level they are diagnosed at is based on the severity of their symptoms and primarily based on how much support they need in their everyday life.

Level 3 autism generally refers to someone who needs a high amount of support in their everyday life. Level 3 ASD might be considered severe autism. Level 1 autism, on the other hand, is when someone requires some support, but support is only minimally needed. Level 1 ASD might be referred to as high-functioning autism. Level 2 is in between level 1 and level 3 regarding how much support a person needs in their everyday life.

Level 1 Autism Spectrum Disorder

Level 1 Autism is sometimes thought of as the least severe or the mildest form of autism. Although there isn’t just one set of characteristics that someone would have who is considered to have level 1 autism, there are some common traits and experiences that people with this autism level might have. For example, most people (children and adults) with level 1 ASD are likely able to communicate verbally using words and more complex language as compared to those with level 3 autism who might not be able to speak using words at all (although some people with level 3 autism can speak with vocal language).

People with level 1 autism often struggle with some aspects of communication and social interactions. They might have difficulty with small talk or with reading social cues. They may have difficulty making or keeping friends (although some people with level 1 ASD may have one or a few friends). Transitions involved in changing activities might be challenging or stressful for someone with level 1 autism.

Level 2 Autism Spectrum Disorder

Level 2 Autism is in the middle of the spectrum as it relates to the level of support a person could benefit from to function more independently and successfully in daily life. When considering the diagnostic criteria for level 2 autism, a person is said to require “substantial support.” Someone with level 2 autism needs more help or more accommodations than someone with level 1 autism. They also often have more difficulties with communication and social skills than a person with level 1 autism experiences.

Someone with level 2 autism might have more noticeable stimming behaviors (sometimes called restricted or repetitive behaviors). Stimming behaviors aren’t something to get rid of, but it is important to note that some stimming behaviors can have a negative impact on one’s quality of life in certain situations. For instance, if someone’s stimming behavior is skin picking, this could have a negative impact on the health of the person’s body. It could also negatively impact accomplishing tasks (if the person is focused on skin picking instead of doing necessary tasks) and it could negatively impact relationships or social experiences.

On the other hand, skin picking might be related to self-regulation and be a coping activity for anxiety or discomfort, so it is paramount that anyone helping the person with autism is aware of the function of the skin picking and be compassionate in their approach to helping the person address their stimming behaviors. Stimming behaviors should be addressed in ways that are in the best interest of the person with autism.

Level 3 Autism Spectrum Disorder

Someone with level 3 autism is considered, by the DSM-5, to “require very substantial support.” What this means is that the person would benefit from more assistance and more accommodations in their daily life – at home, school, work, in the community, in relationships, etc. – in order to function independently and successfully. People with level 3 autism may not speak with verbal language (although some do). They might have very challenging behaviors, such as frequent meltdowns, aggression, or self-harm. They might have more frequent and more intense stimming behaviors. They might have difficulty understanding others. Someone with level 3 autism might need a lot more supervision even when they are an adolescent, or an adult as compared to people with level 1 or level 2 autism.

A Final Thought on Levels of Autism

The levels of autism are an attempt by the medical community to help clarify the needs and abilities of individuals with autism. This can be beneficial in some ways. However, it’s important to note that even someone with level 1 autism might have a very difficult time in certain areas or experiences of life even though they aren’t considered to have the most severe form of autism (level 3 autism). For example, someone with level 1 autism might experience depression or anxiety that is strongly correlated with social difficulties, or they might get bullied or left out in social situations and this can lead to poor mental health and further difficulties in life.

Autism spectrum disorder is complex. People with autism have unique needs and vary as to what support they might need in certain areas of life. Despite this, people with autism also have amazing strengths and abilities that should be recognized and supported, as well.


American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.

American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author.

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