Doctors don't think of an autism diagnosis as a label or a limit. Instead, they use a diagnosis to explain behavior and point to effective treatment. They revise plans often to ensure they use the most accurate words possible. 

As a diagnostic term, autism has moved through plenty of revisions. Years ago, several different words were used to describe people with autism. Now, the umbrella term autism spectrum disorder is the only one that officials recognize. 

Understanding the formal terminology is a critical part of accessing treatments and benefits for someone with autism. Informally, several other terms could be applied to a person with autism. Knowing those words can enhance your knowledge of the condition.

How Do Doctors Describe Autism Right Now?

Doctors use the Diagnostic and Statistical Manual of Mental Disorders (DSM) when placing patients into diagnostic categories. In the fifth edition, issued in 2013, the autism world changed dramatically.

Prior versions included several conditions, such as:

  • Autism.
  • Asperger's syndrome.
  • Childhood disintegrative disorder.
  • Pervasive developmental disorder not otherwise specified (PDD-NOS).

The borders between these conditions were porous, experts explain. Someone visiting one doctor could get a diagnosis of autism. The next day, that same person might get a diagnosis of PDD-NOS from a different doctor.

Diagnostic confusion leads to blurred treatments and stressed families. They don't know which label is true, and they don't know whom to trust. 

In the DSM-5, these conditions were replaced with one term: autism spectrum disorder. That language encompasses the many commonalities these conditions share. The use of the word spectrum recognizes that some people have much deeper impairments than others.

Doctors will use the term autism spectrum disorder (ASD) when discussing patients. Despite this, you might hear families discussing Asperger's syndrome or PDD-NOS in casual conversation, says the Autism Society. These terms are still widely circulated.

Autism Spectrum Disorder: The Accepted Term 

Autism spectrum disorder is the accepted term for people with autism symptoms. This one acronym encompasses many people, behaviors, and levels of impairment. 

Autism Speaks explains that no one is exactly sure what causes ASD. It's likely that a combination of genetics and environment is to blame. Similarly, researchers aren't sure what causes some people to live with mild impairment, while others need around-the-clock caregivers. There's a lot we just don't know about autism despite years of intense research. 

Years of observation highlight typical autism signs and symptoms. Those include changes in:

  • Responses to stimulus. People with autism may not point at objects to highlight interest, and they may not look at things others point to.

  • Relationships. They may not relate to other people. Some don't seem troubled by their lack of connection, while others want to get close and aren't sure how to make it happen.

  • Touch. Some dislike being hugged, held, patted, or squeezed, even by people they know and trust.

  • Speech. Some echo or repeat words while forming few full sentences. Others don't talk at all. Some talk extensively, but only about subjects that interest them.

  • Routine. Many like to stick to the same schedule every day, and they feel distressed when things change. 

  • Senses. Some people with autism feel overwhelmed by loud noises, strong scents, or high levels of visual stimuli.

ASD encompasses a spectrum. Some people have significant impairment, while others seem only moderately affected by the diagnosis. The DSM offers three severity levels for ASD:

  • Level 1, requiring support: Someone at this level has trouble initiating interactions and shows decreased interest in relationships. Inflexible behavior leads to difficulty with everyday activities.

  • Level 2, requiring substantial support: At this level, people have marked difficulty with verbal and nonverbal communication. They have limited social skills. Their inflexibility is obvious to casual observers.

  • Level 3, requiring very substantial support: Someone at this level has severe communication difficulties, including both verbal and nonverbal modes. They have marked difficulty in functioning.

No blood tests or scans help doctors either diagnose ASD or place people on the spectrum. Instead, experts use observation skills and question-and-answer tests to determine how their patients function. 

Diagnosis is important, researchers say, especially at an early age. Children diagnosed with autism before age 4 tend to get effective treatment. Children diagnosed later tend to get less effective therapies, including medication. 

Kids as young as 3 years old have routine autism screenings in wellness checks with doctors. Some school districts hold autism screenings too. Parents can also ask for special assessments if their child’s development seems somehow delayed or they spot the autism symptoms mentioned earlier. 

Outdated Terms That Describe Types of Autism Asperger’s Syndrome

Your doctor won’t use these phrases to describe ASD. But these terms can still be useful to know as you work to understand how a loved one thinks or what that person needs. 

Asperger’s Syndrome

People with this condition won't see the term Asperger's syndrome or Asperger’s disorder on any formal paperwork. This is no longer a recognized diagnostic term. Instead, these people might be described as living on the high-functioning end of the autism spectrum. 

People with Asperger's syndrome have traditional autism difficulties. They struggle with relationships, communication, and order, just as everyone on the spectrum does. But they have behaviors that set them apart. 

The Autism Society explains that classic ASD is often identified by speech delays. Children with autism may not speak at all, or they may speak later than their peers. Children with Asperger's often have very good language skills, but they may:

  • Have unusual speech patterns.
  • Speak in a monotone voice.
  • Talk too loudly or in an unusual pitch.
  • Dominate a conversation, as they may not understand give and take.

Most people with Asperger's have normal to high levels of intelligence that can be measured with traditional tests. They may excel in standard educational or work environments. Many can lead satisfying lives, experts say, but some people will need sustained support to help them live independently. 

People with Asperger's may also benefit from therapy to help them boost communication skills. It's common for people with Asperger's to long for close relationships, but their unusual communication styles can earn them unhelpful labels like "weird" or "awkward."

Therapy could help people understand how others expect them to communicate. It could even help people with Asperger's to explain their thoughts, feelings, and wishes. Deepening understanding through conversation could help them form those connections they yearn for.

Childhood Disintegrative Disorder

Most people with autism develop symptoms somewhat predictably. Children start talking later than their peers, and once problems appear, they don't worsen or disappear. People with childhood disintegrative disorder (CDD) are different. 

Children with CDD have what experts consider a severe, or low-functioning, form of autism, but they don't start off life that way. In some children, symptoms don't appear until age 10. 

Children with CDD hit early development milestones. They may:

  • Accept physical affection.
  • Make eye contact.
  • String together two- or three-word phrases.
  • Relate to others.

Then, they lose those abilities. In a period lasting a few months, children seem to move back through the phases, losing all the skills they developed. Some children also develop a prodrome syndrome in which they experience headaches, anxiety, and nervousness. 

Skills kids lose aren’t regained, and most people with CDD need help for the rest of their lives. Even with therapy, they may not succeed in independent settings.

Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)

Some people don't fit into diagnostic boxes with ease. They may have some symptoms, but others don't fit. They may have some problems, but they don't seem severe. In the past, people like this who didn’t quite fit into the set types of autism were given the PDD-NOS label.

Experts sometimes call this condition atypical autism, and they explain that people with it have:

  • Impairment after age 3. Children younger than 3 years old don't qualify for this diagnosis.

  • Some unusual behaviors. They have demonstrated difficulties in accordance with some autism symptoms.

  • Some atypical behaviors. They may not have all the autism symptoms, or they may have some that aren't normally associated with autism.

People with PDD-NOS have mild forms of autism, experts say. They may have a few social or communication challenges, but they may have many strengths too. 

Some people with PDD-NOS need help to live an independent life, find challenging work, and build healthy relationships. Therapy can be intensely helpful.

Treatment for Types of Autism 

Everyone with autism spectrum disorder is different, and there is no one-size-fits-all treatment that helps every single person in the same way. The best treatments are tailored to fit the individual, and they help people with ASD overcome the challenges that hold them back.

Behavior or psychological therapy is often helpful for people with autism. Doctors refer patients to professionals, and those experts build a treatment team that might include:

  • Parents
  • Siblings
  • Doctors
  • Technicians

A mental health expert builds and administers the treatment program, and the wider team helps to reinforce lessons between appointments. When it comes to autism treatments, practice and repetition lead to sustained change. Families make that possible.

Core challenges vary between people, but many programs focus on:

  • Communication. Asking for a desired object, explaining feelings, or outlining a plan could be therapy targets.

  • Conversation. Understanding how to listen and respond could take up some therapy sessions.

  • Generalizing. Lessons learned at home should be applied in other settings too.

People with low-functioning autism may greatly benefit from therapies that help them master self-care tasks, including brushing their teeth, handling bathroom duties, or washing their hands. 

Applied behavior analysis (ABA) is the gold standard for autism therapy. Therapists identify what clients can and cannot do with ease, and they isolate one or two tasks for targeted therapy. Then, they break those larger tasks into smaller pieces and run drills until the procedures become habitual. 

Therapy is intensive, and it can seem a little repetitive, but that repetition is important. When provided appropriately, ABA therapy can be life-changing for people with autism.

Before researchers discovered ABA therapy, autism was largely considered untreatable. Now, experts understand that people with ASD benefit from this type of focused, intense intervention to help them build skills. With it, people can get better.


Autism treatment does come with limits. People with low-functioning autism, for example, may never gain the ability to speak. Those with high-functioning autism may always feel uncomfortable in some social situations. Therapy doesn’t cure the issue, but it can help the person to cope with it better, reducing symptoms.

Therapy can help people with autism to communicate, at least somewhat, with the world around them. They can use the treatment to make their thoughts and feelings more understandable to the people they love. That could make a big difference in the lives of everyone.