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Types Of Autism: Outdated Terminology For Autism Spectrum Disorder

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Autism rates are steadily on the rise. The CDC released their 2020 report stating that in 1 in 54 American 8 year-olds have been diagnosed with Autism Spectrum Disorder. It is important to know that Autism itself is not one clearly defined disorder. Autism Spectrum Disorder covers a range of disorders that share a core list of symptoms (Source:

The original four main types of autism under Autism Spectrum Disorder are:

  • Classic Autistic Disorder
  • Asperger’s Syndrome
  • Childhood Disintegrative Disorder
  • Pervasive Developmental Disorder (not otherwise specified)

With so much discussion about Autism and so many specialists around, it can feel overwhelming as a parent trying to help and support your child. After 2013, the many different types of Autism have all been categorized together under Autism Spectrum Disorder. However, the use of these terms is still prevalent in most medical communities and online. Let’s learn more.

Understanding the Four Main Types Of Autism and Their Levels

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Autism Spectrum Disorder is a complicated developmental disability. It is critical that if your child shows signs of Autism Spectrum Disorder that they are evaluated by experienced and trained professionals. A medical assessment is required for an official diagnosis of Autism Spectrum Disorder.

Autism Spectrum Disorder (ASD) is the official diagnosis for children and adults that suffer from a range of symptoms and classifications. When diagnosed with ASD, a child will receive their diagnosis and a level.

The levels refer to the type as well as the amount of support the child will need. There are three levels used to classify a child’s autism diagnosis. These levels are:

  • Level 1: Requires support – These children may have difficulty in social situations and experience trouble with initiating social interactions. Their independence can be reduced due to their inability to organize and plan.
  • Level 2: Requiring substantial support – These children practice repetitive behaviors and are limit their social interaction to a few, very specific interests.
  • Level 3: Requiring very substantial support – These children have severe speech and delays and may be non-verbal. They exhibit distress and difficulty in changing focus or activities.

However, the original 4 classifications are still used as terminology and by doctors when explaining the diagnosis to parents. That is why it is helpful to understand what they are and what they mean.

For many years, Rett Syndrome was considered to be a form of Autism. However, after many years of studies, it has been shown to be caused by a genetic mutation and is no longer considered part of the spectrum of disorders that make up ASD.

Enjoying this article? You might also enjoy our blog on the best children’s books about autism. Learn more about how you can do to support your child’s development.

Classic Autistic Disorder

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Sometimes known as Kanner’s Syndrome, Classic Autistic Disorder generally refers to what most people think of when they think of Autism. Children that are diagnosed with Classic Autistic Disorder have significant delays in a range of areas, including social, emotional, language, and behavioral.

These children experience the symptoms of Autism at a more intense level than other classifications of ASD. Children diagnosed with Classic Autistic Disorder tend to keep to themselves and show no interest in engaging with or participating in the world around them.

Classic Autistic Disorder is also commonly referred to as “severe autism” and would fall under a level 3 diagnosis of ASD.

Asperger’s Syndrome

Sometimes referred to as “high-functioning,” children with Asperger’s Syndrome generally show high levels of intellect and are capable of tending to traditional daily tasks and activities. Speech and language delays are uncommon, and in fact, children with the syndrome may talk at great length about a topic that interests them.

These abilities are what separate Asperger’s patients from the other known classifications of Autism. Children with Asperger’s Syndrome tend to have difficulty with social cues and social norms, particularly non-verbal communication.

The most common challenges for those with ASD that fall under what used to be called Asperger’s Syndrome are:

  • Hypersensitivities (to lights, sounds, tastes, etc.)
  • Difficulty with the give and take of conversation
  • Difficulty with nonverbal conversation skills (distance, loudness, tone, etc.)
  • Uncoordinated movements, or clumsiness
  • Anxiety and depression


Childhood Disintegrative Disorder (CDD)

Sometimes called Heller’s Syndrome, CDD is a rare form of Autism that can be difficult for the parents to fully understand. Children with Childhood Disintegrative Disorder tend to develop normally over the first years of their lives. Suddenly, these children regress rather quickly into their symptoms.

“CDD can be particularly tough and confusing for parents because one day, your child is showing no signs of developmental delays, and suddenly they stop talking and interacting.” (From:

Children with CDD are severely impaired in almost every aspect, including language, social, emotional, and behavioral. These children would be a Level 3 in an ASD diagnosis, and CDD is considered one of many Persuasive Developmental Disorders included under the umbrella of Autism Spectrum Disorder.

Pervasive Developmental Disorder: Not Otherwise Specified (PDD-NOS)

While this diagnosis sounds complicated, children diagnosed with PDD-NOS tend to experience a mild range of Autism symptoms and impairments. While not as severe as those with CDD or Classic Autistic Disorder, children with a PDD-NOS diagnosis have a more severe case than those with Asperger’s Syndrome.

This diagnosis is used broadly to describe a series of disorders that now all fall under the ASD umbrella. PDD-NOS “refers to a group of disorders characterized by impairment in the  development of social interaction, verbal and non-verbal communication, imaginative activity, and a limited number of interests and activities that tend to be repetitive.” (Source:

Every Child’s Case Of Autism Is Unique

Because Autism is a spectrum, no two people will fall in the exact same place on the spectrum. Combining the wide range of symptoms and disabilities experienced by children with varying degrees of Autism under one central diagnosis can be confusing for many parents.

However, ASD and its levels or degrees of severity allow for more inclusivity to all children experiencing their distinctive set of challenges, strengths, and symptoms.

Autism Spectrum Disorder is a diagnosis that includes a wide range of developmental delays or impairments and can only be given after a complete and thorough assessment and evaluation by the appropriate professionals.

Most children will show signs and symptoms of being on the spectrum by ages 2 or 3 years old. Early intervention is the best course of action to guarantee as much success as possible for treatment options.

While Autism Spectrum Disorder cannot be cured, many different therapies exist as a way to help a person gain important daily skills and better navigate daily life. These therapies include physical therapy, occupational therapy, behavioral therapy, speech therapy, and prescription medications that are usually used in conjunction with each other.

If your child get an autism spectrum disorder diagnosis, there are many services available that you may want to make sure to take advantage of. These are provided as early intervention in birth to 3 services and through your school for older children with autism spectrum disorders.

These services often include:

  • Speech therapy
  • Occupational therapy
  • Physical therapy
  • Social skills therapy

It is important to remember that there is no one-size-fits-all approach to autism spectrum disorders. Each child and family will require their own specific treatment plans depending on the level of severity as well as each child’s unique personality.

If you are the parent of a child with autism spectrum disorders it is critical that you work closely with your child’s physicians and service providers to ensure the most successful outcome possible. Treatments can be very effective in helping children with ASD live fulfilling and very productive lives. If you think your child may be on the Autism spectrum, speak to your family doctor.

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