What to Know About Level 3 Autism (2023)

Language note: Although individual preferences exist, surveys of the autistic community consistently show that autistic people prefer identity-first language rather than person-first language (i.e., “autistic person” rather than “person with autism”). This article reflects that community language preference.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision, defines autism as a neurodevelopmental disorder that occurs on a spectrum of severity. This language is misleading, as an individual may experience more symptoms in different environments or struggle in some areas but not others. Further, the levels of severity can also be misleading as support needs and traits may vary day to day and in different environments, all in the same person.

Criteria for an Autism Diagnosis

According to the DSM, an individual must meet the following criteria to be diagnosed with autism:

  • “Persistent deficits in social communication and social interaction across multiple contexts.”
  • “Restricted, repetitive patterns of behavior, interests, or activities.”
  • Symptoms begin in early childhood.
  • Symptoms must cause “clinically significant impairment.”
  • Symptoms must not be better explained by another diagnosis.

When a provider diagnoses someone with autism, they can specify severity by indicating whether the autistic person is Level One, Level Two, or Level Three; Level One indicates “mild” symptoms and Level Three indicates more severe difficulties.

What Is Severe Autism?

If the diagnosing provider believes that the individual has “severe” autism, they are typically diagnosed with level three autism. According to the DSM, level three autism is characterized by the following:

  • Social Communication: An autistic person with level three autism experiences “severe deficits” with both verbal and nonverbal communication, “minimal response” to social communication, trouble with initiating social interaction or initiating communication effectively. They may be nonverbal or have limited verbal communication skills.
  • Restricted, Repetitive Behaviors: An autistic person with level three autism has “extreme difficulty” dealing with change and flexibility, and engages in stimming behaviors that “markedly interfere with functioning in all spheres.”

Essentially, if the autistic person has high support needs and has difficulty functioning independently, they can be diagnosed with severe autism. Although some symptoms can be consistent across the lifespan, some autistic people experience an increase in symptom severity while they are experiencing burnout and require more support when this occurs.

Causes of Severe Autism

Below are the main factors that indicate whether or not someone will be autistic.

Autism Runs in Families

Autism runs in families, and an individual is more likely to be autistic if they have an autistic parent or sibling.

Autistic people are at higher risk than the rest of the population for genetic disorders, possibly due to recessive genetic traits that have been linked to autism.

Being Diagnosed With Autism and Another Genetic Disorder

Comorbidity (which means being diagnosed with more than one condition) can affect the severity of symptoms. In other words, some autistic people who also have another type of genetic disorder (e.g.. Down's syndrome, cystic fibrosis, Turner syndrome, etc.) are at a higher risk for “severe” symptoms and high support needs compared to autistic people who have not been diagnosed with another disorder.

The 'Severe' Symptoms Are Likely a Result of the Comorbid Genetic Disorder

However, often symptoms that are attributed to “severe” autism are actually due to the comorbid genetic disorder. In these cases, individuals are labeled as having “severe” autism even though the term is not technically accurate.

(Video) Level 3 Autism symptoms | level 3 ASD | Severe Autism

Accurately labeling the source of various symptoms is an important part of researching these conditions, providing accurate information to the public, and reducing the stigma associated with an autism diagnosis.

Having Older Parents

Although no one factor causes an autistic person to exhibit “severe” symptoms, older parents are more likely to have autistic children than younger parents.

Older Parents More Likely to Pass Down Recessive Genes

Older parents are more likely to produce children with recessive genes or mutations compared to younger parents, and some genetic presentations that correlate with autism are linked to these recessive traits.

Prenatal and Postnatal Factors

Prenatal and postnatal factors can also correlate with more “severe” support needs in autistic individuals, including:

  • Gestational diabetes
  • Hypertension
  • Complications in birth
  • Premature birth

These early environmental factors may introduce stressors that contribute to autistic symptom presentation.

Severe Autism Treatment

Because autism is a neurodivergent condition and not a mental illness, it is not something to be “cured” or “fixed.”

Consider what the goals are before seeking treatment for “severe” autism. Because autistic individuals who are labeled “severe” tend to have high support needs, they are at high risk for abuse or exploitation, and some in the autism industry promote interventions that are harmful or traumatic.

Applied Behavioral Analysis (ABA) Is Harmful

For instance, Applied Behavioral Analysis (ABA) Therapy is still widely used to "treat" autism, however, it forces autistic people to learn behaviors that are supposed to help them appear to be neurotypical or "normal." Many autistic people who have undergone this type of therapy report that it's a traumatic experience. In fact, a PTSD diagnosis is higher among autistic people who have undergone ABA than autistic people who have not.

More Ethical Treatment Options to ABA

Each person has unique needs, and no one treatment plan will be right for every situation. Depending on the person, they may benefit from:

  • Occupational therapy to help manage sensory experiences and overstimulation
  • Speech therapy to help with communication
  • Psychotherapy to treat any comorbid mood issues and provide support and strategies. Any type of therapy, but especially psychotherapy, is the most useful when it is from a provider with lived experience. To reduce the likelihood of trauma, neurodiversity-affirming and competent care is a necessity.
  • Developmental, Individual Differences, Relationship-Basedmodel(aka called “Floor time”) which helps to foster connection between an autistic person and others (e.g., parents, caregivers, teachers. loved ones, etc).

How Autism Is Treated

(Video) Understanding Autism: Chapter 3 - Finding Help for Your Child

Coping With Severe Autism

Autistic people with high support needs may rely on caregivers for their health and safety. Caregivers should know that, even if the autistic person does not communicate through spoken language, they still have opinions and preferences, and they can communicate in other ways to express their needs. Focus on meeting their expressed needs in ways that they prefer and feel comfortable with rather than forcing one specific communication method.

Be mindful of the autistic person’s sensory needs and sensitivities. Try to maintain spaces that are sensory-friendly to the autistic person, and get their input in what their needs are for these spaces

A Word From Verywell

Seek information about what services are appropriate and affirming by listening to the autistic community, and get feedback from other autistic people to ensure that you are centering and prioritizing the autistic person’s needs in their care. The Autistic Self-Advocacy Network is a good starting point for education, support, and resources for autistic people and their caregivers, and their resource database includes information that can help autistic people with various support needs.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Diagnostic and Statistical Manual of Mental Disorders: DSM-5.5th ed., American Psychiatric Association, 2013.DSM-V, doi-org.db29.linccweb.org/10.1176/ appi.

    (Video) Proper Breakdown of Severe Autism | Level 3 Autism | Causes, Symptoms and Treatments

  2. Higgins JM, Arnold SR, Weise J, Pellicano E, Trollor JN. Defining autistic burnout through experts by lived experience: Grounded Delphi method investigating #AutisticBurnout.Autism. 2021;25(8):2356-2369.

  3. Thapar, A., Rutter, M. Genetic Advances in Autism. J Autism Dev Disord 51, 4321–4332 (2021).

  4. Choi L, An JY. Genetic architecture of autism spectrum disorder: Lessons from large-scale genomic studies.Neuroscience & Biobehavioral Reviews. 2021;128:244-257.

  5. Cleveland Clinic. Genetic Disorders.

  6. Saldarriaga W, Payán-Gómez C, González-Teshima LY, Rosa L, Tassone F, Hagerman RJ. Double genetic hit: fragile x syndrome and partial deletion of protein patched homolog 1 antisense as cause of severe autism spectrum disorder.J Dev Behav Pediatr. 2020;41(9):724-728.

  7. Hodges H, Fealko C, Soares N. Autism spectrum disorder: definition, epidemiology, causes, and clinical evaluation.Transl Pediatr. 2020;9(S1):S55-S65.

  8. Wang C, Geng H, Liu W, Zhang G. Prenatal, perinatal, and postnatal factors associated with autism: A meta-analysis.Medicine. 2017;96(18):e6696.

  9. Leaf JB, Cihon JH, Leaf R, et al. Concerns About ABA-Based Intervention: An Evaluation and Recommendations [published correction appears in J Autism Dev Disord. 2021 Jul 20;:].J Autism Dev Disord. 2022;52(6):2838-2853. doi:10.1007/s10803-021-05137-y

  10. CDC. Treatment and interventions for autism spectrum disorder.

What to Know About Level 3 Autism (1)

By Amy Marschall, PsyD
Dr. Amy Marschall is a clinical psychologist who works with children and adolescents. She is certified in TF-CBT and telemental health.

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What can I expect at level 3 autism? ›

ASD level 3 is characterized by severe challenges in social communication as well as extremely inflexible behavior. Children with level 3 autism will be nonverbal or have the use of only a few words of intelligible speech. Initiation of social interaction is very limited, as well as response to others.

What questions will I be asked in an autism assessment? ›

What happens during an autism assessment
  • ask you about your child's development, such as when they started talking.
  • watch how you and your child interact, and how your child plays.
  • read any reports sent by their GP, nursery or school.
  • ask about their medical history and do a physical examination.

Is Level 3 autism severe? ›

Level 3 ASD is the most severe form of autism spectrum disorder. People with Level 3 ASD show significant difficulties with social communication and social skills. They also have restrictive or repetitive behaviors that often get in the way of functioning independently and successfully with everyday activities.

What percentage of autism is Level 3? ›

Summary Autism spectrum disorders (ASD) resulted in 4·31 million (95% UI 2·82–6·23) global DALYs in 2019, equivalent to 0·2% (0·1–0·2) of DALYs.
Autism spectrum disorders — Level 3 cause.
Total sources
5 more rows

Can Level 3 autism improve? ›

Can level 3 autism get better? Autism cannot be cured, and support for those with severe autism will always be needed. However, treatment can help a person better manage symptoms.

What does Level 3 autism look like in adults? ›

Level 3 Autism

Capacity to only speak one or two words at a time. Rarely, if at all, social interactions on their own. Very rigid in behavior. Difficulty adapting to change, which causes intense feelings of distress.

Does autism run in families? ›

If someone in your family has autism spectrum disorder (ASD), you may be more likely to have a child with ASD. ASD can look very different from person to person, so taking a careful family health history can be important for early diagnosis.

What are the 3 main symptoms of autism? ›

Main signs of autism

finding it hard to understand what others are thinking or feeling. getting very anxious about social situations. finding it hard to make friends or preferring to be on your own.

What is the best assessment tool for autism? ›

The most common assessments for ASD include:
  • Autism Diagnostic Observation Schedule - Second Edition (ADOS-2) ...
  • Autism Diagnosis Interview-Revised (ADI-R) ...
  • Childhood Autism Rating Scale, Second Edition (CARS-2)
3 Jun 2021

At what age should an autistic child be potty trained? ›

Here are seven tips to help toilet train your child with autism or another developmental disability: Wait until the child is ready. There is no magic age or perfect time to potty train. Kids generally show readiness between the ages of two and four, but sometimes a child isn't ready then.

What is considered severe autism? ›

Level 3 is the most severe level of autism. People with level 3 autism have limited ability to speak clearly. Difficulty with both verbal and nonverbal communication makes it challenging to interact with others. This level of autism requires a higher level of support throughout life.

What is considered high functioning autism? ›

“High-functioning autism” isn't an official medical term or diagnosis. It's an informal one some people use when they talk about people with an autism spectrum disorder who can speak, read, write, and handle basic life skills like eating and getting dressed. They can live independently.

Does mild autism get better with age? ›

Change in severity of autism symptoms and optimal outcome

One key finding was that children's symptom severity can change with age. In fact, children can improve and get better. "We found that nearly 30% of young children have less severe autism symptoms at age 6 than they did at age 3.


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