What Is Autism?

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Autism, or autism spectrum disorder (ASD), is a lifelong developmental disorder that can include differences or challenges with social communication skills, fine and gross motor skills, speech, and intellectual ability. Symptoms and severity vary widely. Most cases are diagnosed in childhood and last throughout life. And while there is no established cure for autism, behavioral, educational, and family therapy may help reduce symptoms and build skills.

Though the disorder brings challenges, a diagnosis also often highlights an individual's unique strengths. It is important to know that autism is neither a mental illness nor a condition that gets worse over time. In fact, most people with autism become better able to manage life with their condition, particularly with intensive treatment.

Autism was first described as a distinct disorder during the 1930s. The definition, however, has changed radically over the years. Today, with the publication of the Diagnostic and Statistical Manual of Mental Disorders, Version 5 (DSM-5), there is only one diagnostic category for people with autism: autism spectrum disorder.

Autism Symptoms

The symptoms of autism are usually seen before age three. They include impairments in communication, social interactions, and responsiveness. People with ASD often have atypical responses to sensory input, like unusual sensitivity to light, sound, smell, taste, or sensory cravings. Other common symptoms include "stims" (hand flapping, toe walking, rocking), a need for sameness and repetition, anxiety, and—in some cases—impressive "savant" abilities in certain areas (often music and math).

3 functional levels of autism
Illustration by Cindy Chung, Verywell

Because autism is a spectrum disorder, it is possible to be mildly, moderately, or severely autistic. Confusingly, you can also have a combination of mild and severe symptoms. For example, it is possible to be very intelligent and verbal, but also have severe symptoms of anxiety and sensory dysfunction.

Severe forms of autism can be very difficult to manage because they can come along with aggressive behaviors and extreme communication challenges. But high functioning autism is often accompanied by mental health issues such as anxiety, obsessive behaviors, serious sensory dysfunction, and even depression.


In most cases, the cause of autism is unknown. It may be that both genetics and the environment are involved. Research is looking into differences in the structure and function of the brain with autism, as people with the disorder seem to have larger brains and process information differently.

A few drugs, taken during pregnancy, can increase the risk of autism, and it is more frequent with some genetic syndromes. Outside of that, however, knowledge on this is limited.

Boys are at much higher risk than girls, and older parents are more likely to have children with autism, though nobody knows why. Autism seems to run in families, but there is no way to know if a baby will or will not have ASD.

Vaccines do not cause autism, and neither does poor parenting. These theories have been soundly refuted by the medical community.


A parent, caregiver, or teacher may very well be the first person to notice signs of autism in a child, but it's important that you seek out a professional for a diagnosis.

It's never too early for screening and evaluation. It's also never too late, so an older child or adult can benefit from going through the diagnostic process.

The testing for autism involves interviews, observation, and evaluations by a psychologist, developmental pediatrician, or pediatric neurologist. Screening may include IQ tests, speech evaluations, occupational therapy evaluations, hearing tests, autism-specific questionnaires, and more.

None of these tests are perfect, and a child's challenges can get in the way of the testing process. The professional may not be able to make a definitive diagnosis.

If your young child was recently diagnosed with autism, it's a good idea to seek a second opinion—especially if the diagnosis came from a source other than a professional with extensive autism experience.

Functional Levels

Anyone with symptoms consistent with autism will receive an ASD diagnosis, along with a functional level:

  • 1 (High-functioning)
  • 2 (Moderately severe)
  • 3 (Severe)

If appropriate, specifiers will also be included in the diagnosis. Some common specifiers include cognitive disabilities and seizure disorders.

What About Asperger's Syndrome?

Asperger's syndrome used to be a specific autism diagnosis, but since the release of the DSM-5, it falls under autism spectrum disorder. While the term is no longer used by clinicians, many people with high functioning autism still describe themselves as having Asperger's syndrome, likely because of a long history of the name's use and the fact that it described such a specific diagnostic category.


There are many effective autism treatments, but no known cure. Autism treatments are rarely medical, but instead include intensive behavioral, developmental, speech, and occupational therapy. In many cases, therapies can have a significantly positive impact.

Once you've confirmed your child's diagnosis, a good next step is to contact your pediatrician and school district to set up early intervention services. You may also want to look into therapeutic preschool programs and playgroups.

Behavioral therapy is the oldest and most fully researched treatment specifically developed for autism. Applied behavioral analysis (ABA) is a reward-based training that focuses on teaching particular skills and behaviors. Pivotal response therapy is another type.

Developmental therapies such as floor time, SCERTS, and relationship development intervention (RDI) are aimed at increasing emotional, social, and intellectual skills. They can include play therapy and recreational therapy.

Medications might be used to address severe symptoms and behavior, but they are not cures. For example, Risperdal may help with irritability, aggression, and self-injury, while SSRI antidepressants like Zoloft may help relieve anxiety.

When adults are diagnosed with autism, it is usually because they are living with relatively mild symptoms, so therapies and medications are optional. They might find a therapist with appropriate experience or seek help with sensory challenges.

When researching autism, be sure to check out your sources carefully, as there is a great deal of misinformation available online and through the grapevine. There are many disproven alternative therapies, such as chelation, which not only are unhelpful but can be dangerous.

A Word From Verywell

A diagnosis of autism can be overwhelming. It's important to know that it is more than possible to live well with autism. Over time, you will discover a wide range of resources and opportunities available to children with autism and their families. You'll also discover your own ability to cope—and even thrive—while parenting an autistic child.

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