What Are the Different Levels of Autism?

Health providers use a handbook called the Diagnostic and Statistical Manual of Mental Disorders (DSM) to diagnose mental disorders, including autism spectrum disorder (ASD). Until 2013, the DSM-4 (fourth edition) listed four separate diagnoses within the category of pervasive developmental disorder: autistic disorder, Asperger’s syndrome, childhood disintegrative disorder, and pervasive developmental disorder (PDD-NOS).

As the name implies, autism spectrum disorder is a neurodevelopmental condition with symptoms and severity that fall across a spectrum. Each autistic person’s symptoms are unique, and severity varies from person to person. Some people with autism may have severe symptoms that impact their daily functioning, while others may experience less severe challenges.

Autism severity levels define how much support someone with autism needs, ranging from basic to very substantial support. However, all people with autism share challenges in two core areas: social communication and interaction and restricted and repetitive behaviors.

• Different rates of development, such as language development, than others
• Repetitive vocalizations of words or phrases, called echolalia
• Difficulty understanding other people’s feelings
• Repetitive behaviors, such as hand flapping, spinning, or rocking
• Unusual and intense reactions to sensory stimuli, including sounds, smells, tastes, textures, lights, or colors
• Difficulty with transitions and changes in routine or surroundings
• Restricted or obsessive interests

Level 1 autism means you require support to redirect your restricted, repetitive behaviors and navigate social communication challenges. These challenges may include initiating social interactions or having difficulty interpreting and responding to social cues. You may also have little interest in social interactions.

People with level 2 autism experience significant delays in both verbal and non-verbal communication and require substantial support. Impaired social functioning makes it challenging to form and maintain relationships, even with the proper support. If you have level 2 autism, you might display unusual nonverbal communication, speak in simple sentences, and only want to interact with others about a specific interest.

People with level 3 autism require very substantial support to address severe impairments in many areas of everyday life. Verbal and nonverbal communication is severely limited in people with level 3 autism.

In many cases, a person with level 3 autism’s speech may be unclear, making it difficult for others to understand verbal communication attempts. People with level 3 autism also experience compromised social interactions: They may not initiate social interactions at all and minimally (if at all) respond to others’ social gestures.

• Autism spectrum disorder is no longer categorized into different types but is now diagnosed based on levels of support needs. This approach recognizes the individual challenges and needs of each person with autism.
• People with ASD share core difficulties in social interaction and communication as well as repetitive behaviors and restricted interests, though symptoms vary widely.
• The levels of ASD — ranging from level 1 (requiring support) to level 3 (requiring very substantial support) — help healthcare providers tailor interventions and resources, promoting better outcomes for individuals.
• Early diagnosis and support can enhance a person with autism’s quality of life and functional skills. So if you need more support for autism, or if you show symptoms of ASD but haven’t been evaluated, talk to your healthcare provider to find out the best next steps to meet your needs.