Updated: September 15, 2026

Since the DSM-5 (2013), autism is diagnosed as a single condition — autism spectrum disorder (ASD) — described using three support levels rather than separate types. The "five types" of autism people often search for (classic autism, Asperger syndrome, PDD-NOS, childhood disintegrative disorder, and Rett syndrome) were DSM-IV categories that are no longer diagnosed separately: four were folded into ASD, and Rett syndrome is now classified as its own genetic condition.

Is there more than one type of autism?

Historically, the medical community categorized autism into five distinct types: Classic Autism, Asperger Syndrome, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), Childhood Disintegrative Disorder, and Rett Syndrome.

However, this classification has evolved significantly. In contemporary understanding, Rett Syndrome is considered a separate condition, while the other four have been incorporated into the broader autism spectrum.

This shift from distinct categories to a spectrum approach acknowledges the diverse ways autism can manifest and recognizes that individuals may not fit neatly into predefined boxes.

The evolution from distinct subtypes to a spectrum approach for understanding autism spectrum disorders marks a significant shift in the field. In 2013, the American Psychiatric Association released the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

This updated manual incorporated previously separate categories like Autistic Disorder, Asperger's Disorder, and PDD-NOS under the umbrella term "Autism Spectrum Disorder." This change recognizes that autism exists along a continuum, with individuals exhibiting varying combinations and severities of symptoms rather than fitting into discrete categories.

Rett syndrome, the fifth former category, was removed from the autism spectrum entirely and is now classified as its own genetic condition. The DSM-5-TR (2022) kept this structure, clarifying the wording of the diagnostic criteria without changing the levels themselves.

The 3 levels of autism spectrum disorder

Recognizing the wide range of support needs within the autism spectrum, the DSM-5 also introduced three levels of severity for ASD:

Level	Description	Required Support
Level 1	Requiring Support	Difficulty initiating social interactions and challenges switching between activities. Support may not be readily apparent to others.
Level 2	Requiring Substantial Support	Noticeable social challenges, even with support. Repetitive behaviors and/or sensory sensitivities may significantly interfere with daily function.
Level 3	Requiring Very Substantial Support	Severe deficits in verbal and nonverbal communication skills, limited social interaction. Repetitive behaviors significantly interfere with functioning in all areas.

These levels help guide support services and interventions, ensuring individuals receive the right level of assistance based on their unique needs.

For a full breakdown of each level's clinical criteria, see our complete guide to autism spectrum disorder levels.

Level 1: Requiring support

Level 1 describes people who need some support but can often live independently in many areas of life. They may have difficulty initiating social interactions, struggle to switch between activities, or have narrow, intense interests, though these traits may not be obvious to others.

Level 1 is sometimes called "mild autism" or, informally, "high-functioning autism," though neither is an official clinical term.

Our guides to Level 1 autism and the mildest form of autism go into more depth on what this level looks like day to day.

Level 2: Requiring substantial support

Level 2 involves noticeable social communication challenges even when support is in place, along with repetitive behaviors or sensory sensitivities that interfere with functioning in more than one setting. Children at this level typically need consistent, structured intervention to build communication and daily-living skills. Support needs are more visible than at Level 1, and school or home routines often need to be adapted around them.

Level 3: Requiring very substantial support

Level 3 describes the most extensive support needs: severe deficits in verbal and nonverbal communication, very limited social interaction, and repetitive behaviors that significantly interfere with functioning across all settings. People at this level typically require intensive, ongoing support with communication, daily living, and behavior regulation.

The 5 former types of autism (DSM-IV) and what they are called now

Let's examine these earlier classifications to better understand the shift in perspective. None of these is an active clinical diagnosis today — here's what each one is called now.

1. Classic Autism

Classic autism, also known as Kanner’s syndrome or autistic disorder, represents what was previously considered the most severe form of autism. Children diagnosed with classic autism typically display significant challenges in social interaction, communication, and behavior. They may struggle with verbal and non-verbal communication, including limited eye contact and difficulty understanding and responding to social cues.

Furthermore, individuals with classic autism often exhibit repetitive behaviors, such as hand flapping or rocking, and can be deeply affected by changes in routine. While this term is no longer a distinct diagnosis, it provides context for understanding the historical categorization of autism.

Today, someone who would have received this diagnosis is diagnosed with autism spectrum disorder — typically at Level 2 or Level 3, depending on their individual support needs.

2. Asperger Syndrome

Asperger Syndrome, named after Hans Asperger, was characterized by difficulties in social interaction and communication, similar to classic autism but often with less severe symptoms. Individuals with Asperger Syndrome typically have average or above-average intelligence and language development. However, they may struggle with understanding social cues, engaging in reciprocal conversations, and forming relationships.

They often have intense interests in specific subjects and may engage in repetitive behaviors. With the shift to a spectrum approach, Asperger Syndrome is no longer a separate diagnosis but is understood as part of the broader autism spectrum.

Under the DSM-5, this generally corresponds to Level 1. See our comparison of high-functioning autism and Asperger'sand our explainer on why "high-functioning autism" is no longer used clinically for more on this shift.

3. Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS)

Individuals with PDD-NOS exhibit symptoms that align with autism spectrum disorders but may not meet specific criteria for other types of autism. This can lead to challenges in receiving a precise diagnosis. PDD-NOS encompasses a broad range of symptoms, impact social skills, communication abilities, and behavior patterns.

Understanding this subtype is crucial for tailored intervention strategies and support. The varied presentation of PDD-NOS underscores the complex nature of autism spectrum disorders and emphasizes the need for individualized approaches.

It's now part of autism spectrum disorder. Most people who would have received this diagnosis fall at Level 1 or Level 2 today, depending on their support needs.

4. Childhood Disintegrative Disorder

Childhood Disintegrative Disorder, a rare condition, is characterized by a period of typical development followed by a significant regression in skills, typically between the ages of two and four. Children who develop this disorder may lose previously acquired abilities, such as language, social skills, and bladder or bowel control. The cause of this regression is not fully understood and can be incredibly distressing for families.

While no longer considered a distinct autism subtype, understanding Childhood Disintegrative Disorder contributes to a more comprehensive understanding of the diverse developmental trajectories that can occur within the autism spectrum. It's now diagnosed as autism spectrum disorder, typically at Level 3 given the extent of support most affected children need.

5. Rett Syndrome

Rett Syndrome, primarily affecting females, is a genetic disorder characterized by a period of normal development followed by a slowing of development and the loss of previously acquired skills. Unlike the other four conditions discussed, Rett Syndrome is no longer categorized within the autism spectrum.

This distinction arises because Rett Syndrome stems from a specific genetic mutation, setting it apart from other forms of autism. Common symptoms include:

Repetitive hand movements.
Loss of spoken language.
Difficulty walking.
Seizures.

Different Types of Autism? & Other Q&As

Our guide on Rett's autism explains the current understanding of this condition and how it differs from ASD.

Diagnosis and Early Signs of Autism Spectrum Disorders

Early diagnosis of autism spectrum disorders is crucial, as it allows for timely intervention and support. Parents and caregivers play a vital role in recognizing early signs and seeking professional evaluation. These signs can be subtle and sometimes easily overlooked, highlighting the need for increased awareness and understanding of ASD.

Key Indicators in Infants and Toddlers

While the signs of autism spectrum disorders can vary, some common indicators emerge during infancy and toddlerhood. Parents and caregivers should be aware of these potential red flags:

Limited eye contact: Difficulty establishing and maintaining eye contact, particularly with caregivers.
Delayed language development: Showing delays in babbling, speaking first words, or using gestures compared to other children their age.
Lack of response to name: Not consistently responding to their name being called.
Repetitive behaviors: Engaging in repetitive movements, such as hand flapping, rocking, or lining up toys.
Unusual reactions to sensory input: Displaying heightened or diminished responses to sounds, textures, or lights.

A professional diagnosis is a multi-step process involving pediatricians, psychologists, and speech-language pathologists, who review developmental history, observe behavior across settings, and use standardized assessments before assigning a level. For the full evaluation process, see our guide to autism diagnosis criteria.

Addressing Autism: Treatment Options and Strategies

While there's no one-size-fits-all cure for autism spectrum disorders, various treatment options and strategies can significantly improve an individual's quality of life. The focus is on addressing the specific challenges presented by ASD and fostering the individual's strengths and abilities.

Behavioral and Educational Interventions

Behavioral and educational interventions form the cornerstone of autism treatment. Applied Behavior Analysis (ABA) is a widely recognized and effective therapy that focuses on understanding the relationship between behavior and the environment.

Medical and Therapeutic Approaches

While the medical community primarily focuses on behavioral and educational interventions for autism spectrum disorders, additional therapeutic approaches can complement these treatments. Speech therapy helps improve communication skills, both verbal and nonverbal, while occupational therapy addresses fine motor skills, sensory processing issues, and daily living activities.

At True Progress Therapy, our in-home ABA therapy delivers this support directly in a child's everyday environment, where new skills are practiced in the same settings families actually live in.

Conclusion

In conclusion, understanding the diverse spectrum of Autism Spectrum Disorders is crucial for fostering acceptance and support for individuals at every support level. Each person's needs look different, and understanding this shift matters most for making sure a "milder" level or an outdated label like Asperger's doesn't get mistaken for needing less support. By embracing a spectrum approach and promoting early diagnosis, we can enhance the lives of those with ASD.

Educating oneself on the signs, treatments, and resources available is key to creating a more inclusive and compassionate society for individuals with autism. If you seek further information or support, explore the wealth of resources available to families affected by ASD. Together, we can advocate for understanding and empowerment within the autism community.

At True Progress Therapy, we understand that no two children with Autism Spectrum Disorder (ASD) are the same. That's why our tailored ABA therapy programs in New Jersey are designed to meet each child's unique needs, helping them build essential communication, social, and life skills.

Our dedicated team of therapists uses evidence-based techniques to foster meaningful progress in a supportive environment. Give your child the opportunity to thrive—schedule a consultation today!

Frequently Asked Questions

What are the 5 different types of autism?

The "5 types" — classic autism, Asperger syndrome, PDD-NOS, childhood disintegrative disorder, and Rett syndrome — were DSM-IV categories retired in 2013. Today, the first three and childhood disintegrative disorder fall under one diagnosis, autism spectrum disorder, described by support level rather than type. Rett syndrome is now classified as a separate genetic condition, not a form of autism.

What are the 3 main types of autism?

There aren't three "types" of autism — there's one diagnosis, autism spectrum disorder, with three DSM-5 support levels. Level 1 means a person requires support, Level 2 means substantial support, and Level 3 means very substantial support across daily activities. Levels describe support needs, not separate conditions or fixed severities.

Are there 7 types of autism?

No. There's no clinically recognized system of 7 autism types. The only current diagnostic framework is the DSM-5's single diagnosis, autism spectrum disorder, with three support levels. Lists describing "7 types" online typically mix outdated DSM-IV categories, informal terms like "high-functioning," and unrelated conditions that aren't part of any official classification.

What is the mildest type of autism?

What people usually mean by "mildest type" is ASD Level 1, requiring support — the level associated with the fewest daily support needs. It's sometimes called "mild autism" or, informally, "high-functioning autism," though neither is an official clinical term. Level 1 still benefits from support like social skills training and executive-functioning coaching.

Can the type or level of autism change over time?

A person's autism spectrum disorder diagnosis doesn't change, but their assigned level can be reassessed as their support needs shift. With early intervention, some children need less support over time; others may need more as demands increase with age. Levels describe current support needs, not a fixed severity a person is locked into.

Sources:

https://www.webmd.com/brain/autism/autism-spectrum-disorders

https://www.medicalnewstoday.com/articles/types-of-autism

https://www.healthline.com/health/types-of-autism

https://mhcsandiego.com/blog/types-of-autism/

https://www.autismparentingmagazine.com/understanding-autism-subtypes/

https://www.psychiatry.org/getmedia/d48f7fa6-b6c8-4f6c-888b-b0adfeb9f5b6/APA-DSM5TR-AutismSpectrumDisorder.pdf