What Is Autism?

parents drawing with their child

Verywell / Laura Porter

Table of Contents
View All
Table of Contents

Autism, also known as autism spectrum disorder, is a developmental disorder characterized by communication, social, and behavior challenges. The condition is lifelong and symptoms can vary considerably from one person to the next.

Symptoms involve challenges or differences in motor skills and both intellectual and social abilities. People with autism may learn, act, think, communicate, and interact differently than people who do not have autism spectrum disorder.

Autism is referred to as a spectrum disorder because there is so much variation in terms of the type of symptoms people experience and the severity of those symptoms.


While symptoms are often highly variable, they usually begin to appear before the age of three. Parents may notice symptoms associated with how children interact socially, their responsiveness to stimulation, and their ability to communicate.

Symptoms of autism include repetitive behaviors, limited interests, and problems with interaction.

While people with autism spectrum disorder may not show all of these symptoms, they usually show several of the following:

  • Trouble making eye contact
  • Difficulty following and engaging in conversations
  • Extreme distress when routines are even slightly disrupted
  • Facial expressions that don't match verbal communication
  • Intense interest in certain subjects
  • Lack of enjoyment in activities
  • Problems expressing feelings or needs in words
  • Not engaging in “pretend” play
  • Slow or absent response to people trying to gain their attention
  • Sensitivity to sensory stimuli including taste, light, and smell
  • Stimming behaviors (i.e., self-stimulating, repetitive actions such rocking, walking on toes, or flapping hands)
  • Trouble seeing things from another person’s point of view

It's important to remember that because autism is a spectrum condition, people can have symptoms that are described as mild , moderate, or severe . Some people may have several or many symptoms, but only experience them to a mild degree.

In other cases, people might only have a few symptoms in key areas but experience severe impairments as a result of those symptoms.

People who have milder autism symptoms are often able to function in their daily lives, but they may be more likely to have other mental health concerns including excessive stress, obsessive behaviors, sensory issues, anxiety, and depression .

Autism is usually diagnosed in childhood and it can occur in people of all economic backgrounds, races, and ethnicities.

Signs to Watch For

Every child is different, but some signs that may indicate that a professional evaluation is needed include:

  • Lack of smiling or happy expressions by six months
  • No babbling by age one
  • Lack of response when a child's name is called
  • Not reaching for objects by age one
  • Lack of single-word speech by 16 months
  • No two-word phrases by age 2
  • Loss of any speech or social skills


Signs of autism are typically first noticed by parents, but they may also be spotted by other caregivers, teachers, and doctors.

Early screening and evaluation are important. If you are concerned about your child's behavior, it is important to talk to your child's doctor. The sooner a diagnosis is made, the sooner interventions can begin.

There is no specific test that can determine if someone has autism. Doctors can diagnose autism by looking at behaviors and asking questions about development.


During regular developmental checkups during childhood, doctors track a number of developmental milestones and screen for different types of developmental delays. When children don't meet certain milestones, they may receive further evaluation.

During an additional evaluation, a group of specialists that may include a developmental pediatrician, a child psychiatrist, and a speech-language pathologist, will assess a number of things including age-appropriate behaviors, cognitive skills, and language abilities.

Some types of tests that may be used in the diagnosis of autism include:

  • Autism-symptom questionnaires
  • Developmental monitoring
  • Hearing tests
  • IQ tests

Autism can be reliably diagnosed in children as young as age two.   Symptoms begin to appear during the first three years of a child’s life.

Diagnosis in Adulthood

While autism is often diagnosed in early childhood, it can also be diagnosed during adolescence and adulthood . Diagnosis later in life can sometimes be more difficult since some symptoms of autism can be confused with other mental health conditions such as anxiety, OCD , and ADHD .

While researchers are still studying what types of treatments work best for adults with autism, getting a diagnosis can be helpful for understanding both current and past difficulties. It can also help you learn how to recognize your strengths and get help in areas where you may struggle.

Early diagnosis is usually ideal, but it is never too late to be evaluated, diagnosed, and treated for autism. If you are experiencing symptoms that may be related to autism, talk to your doctor to learn more.


According to statistics from the Centers for Disease Control and Prevention (CDC), one in 54 eight-year-old children has autism spectrum disorder. They also reported that the condition was present in all ethnic, racial, and socioeconomic groups.

However, they found that autism is four times more common in boys than in girls .

Prevalence statistics also indicate that autism is more common now than in the past. It also appears to be increasing, growing as much as 10 to 17% over the past few years.


While the exact causes are not known, research suggests that there is likely a genetic aspect to the condition.

Research that points to a genetic connection includes studies showing that children who have a sibling with autism are at a higher risk of having autism.

However, research has also found that only around 20% can be directly attributable to genetic causes. Further research is needed to better understand how specific genetic mutations or variations may contribute to the development of autism spectrum disorder.

While genes are thought to be a key contributor, studies have also shown that premature birth and advanced paternal age are also linked to the onset of autism.

Certain drugs, when taken during pregnancy, have been linked to a higher risk for autism spectrum disorder.

Research has demonstrated that vaccines do not cause autism.  


When a person is diagnosed with autism, they will also have their functional level identified. There are three different levels of autism spectrum disorder:

  • Level 1: High functioning
  • Level 2: Moderately severe
  • Level 3: Severe

These levels are used to describe how severely behaviors and social skills are affected.

Level 1

Level 1 is considered a mild form of autism. People who have this type may have problems with social relationships and restrictive behaviors. They usually only need minimal support to function in their normal daily life.

Level 2

Those with Level 2 autism spectrum disorder need more support. Their social difficulties are apparent, they may have problems communicating, and may need assistance to manage problematic behaviors.

Level 3

People with Level 3 autism have symptoms that interfere with their ability to live and function independently. People with this level of autism often do not communicate verbally, struggle with change, have repetitive or restrictive behaviors, and may be sensitive to sensory stimuli.

Previous Types

The 2013 publication of the Diagnostic and Statistical Manual of Mental Disorders (DSM) marked significant changes in how autism was classified and diagnosed. Until the publication of the DSM-5, experts referred to different types of autism. These included:

  • Asperger's syndrome was described as a milder form of autism marked by normal intellectual functioning but difficulty with social interaction.
  • Pervasive developmental disorder, not otherwise specified (PDD-NOS) was a moderate form of autism that was more pronounced than Asperger's.
  • Autistic disorder was a more severe form of autism marked by more serious deficits than Asperger’s and PDD-NOS.

Today, these conditions are simply known as autism spectrum disorder. While the above types are no longer official diagnoses, some people still find them useful as a way to describe how symptoms are experienced and their severity. For example, people often find that Asperger's is helpful as a self-identity or to connect with peers with similar experiences.


While autism is a lifelong condition, there are treatments that can help with many symptoms and improve people’s ability to function in different areas of life.

According to the National Institute of Mental Health, treatment should begin as quickly as possible following a diagnosis.  

There is no single treatment that is best. People with autism have a wide range of symptoms so that means that each person's needs are different. Some of the treatment options that might be used include medications and therapy.


While there is no medication approved for the treatment of autism, a doctor may prescribe certain medications to alleviate certain symptoms.

Medications such as selective serotonin reuptake inhibitors (SSRIs) , anti-psychotics, stimulants , anti-anxiety medications, and anticonvulsants may help with symptoms such as:

  • Aggression
  • Anxiety
  • Attention problems
  • Depression
  • Hyperactivity
  • Inappropriate speech
  • Irritability
  • Social withdrawal

Behavioral and Developmental Therapy

Treatment for autism often focuses on behavioral, psychological, or skills training interventions.

One commonly used approach is applied behavior analysis (ABA), a form of therapy that utilizes reinforcements to teach and reinforce desirable behaviors and skills.

Other common therapies used in the treatment of autism include:

  • Cognitive-behavioral therapy (CBT)
  • Developmental and individual differences relationship therapy (also known as “floortime”)
  • Early intensive behavioral intervention
  • Pivotal response therapy
  • Relationship development intervention
  • Verbal behavior therapy

Such treatments are designed to help people with autism spectrum disorder to:

  • Foster cognitive abilities
  • Improve existing strengths
  • Increase language and communication skills
  • Improve social skills
  • Learn adaptive skills that allow for independent living

Other therapies that may be used include assistive technology, speech therapy, occupational therapy, and social skills training. Treatment also often incorporates aspects of caregiver training in which parents and other caregivers learn skills that will help them reinforce what is being worked on in treatment.


In addition to seeking professional treatment, there are also a number of self-help strategies that you can use to help cope with some of the symptoms of autism. Some things that can help:

Be Accepting

Rather than focusing on differences, try viewing these unique characteristics as just part of who someone is. Practice acceptance and unconditional love instead of focusing on trying to "fix" the things that make someone different from others.

Create a Relaxing and Comfortable Environment

Pay attention to things that may be a source of stress including sensory stimuli such as loud noises or bright lights.

Follow A Schedule

People with autism do best with routines and structure. Keep things consistent each day including meals, school, appointments, therapy, and bedtime. When there are going to be changes or disruptions, be sure to give the individual plenty of warning and time to prepare.

Join a Support Group

Look for local support groups in your area or join a group online. You can share experience, get support, learn about treatments, and discover resources and programs related to autism spectrum disorder.

Learn to Identify Triggers

If there are certain things that tend to trigger disruptive or challenging behaviors, you can find ways to prevent or modify those difficult situations.

Pay Attention to Nonverbal Communication

Because people with autism often struggle with communication and social behaviors, they may not be able to tell you what’s wrong. Look at things such as facial expressions, body language , and other nonverbal signals.

Use Positive Reinforcement

The goal is to offer a reward when you "catch them being good." When you notice that they are using a new skill or are doing something good, praise them for it. Verbal encouragement can go a long way, but you can also use other desired rewards such as stickers or preferred activities as a way to reinforce appropriate behaviors.

A Word From Verywell

Autism is a complex condition that can cause various degrees of impairment and affect a person's life in many different areas. Early intervention is important and there are many types of treatment and resources available to help. Finding the right treatment for yourself or your loved one can help them function more independently and live a fulfilling life.

7 Sources
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. Centers for Disease Control and Prevention. Screening and diagnosis of autism spectrum disorder .

  2. Lord C, Risi S, DiLavore PS, Shulman C, Thurm A, Pickles A. Autism from 2 to 9 years of age . Arch Gen Psychiatry . 2006;63(6):694-701. doi: 10.1001/archpsyc.63.6.694. PMID: 16754843

  3. National Institute of Mental Health. Autism spectrum disorder .

  4. Centers for Disease Control and Prevention. Prevalence of autism spectrum disorder among children aged 8 years—autism and developmental disabilities monitoring network, 11 sites, United States, 2016 .

  5. Cleveland Clinic. Autism .

  6. Centers for Disease Control and Prevention. What is autism spectrum disorder? .

  7. Taylor LE, Swerdfeger AL, Eslick GD. Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies . Vaccine . 201417;32(29):3623-9. doi:10.1016/j.vaccine.2014.04.085

By Kendra Cherry
Kendra Cherry, MS, is the author of the "Everything Psychology Book (2nd Edition)" and has written thousands of articles on diverse psychology topics. Kendra holds a Master of Science degree in education from Boise State University with a primary research interest in educational psychology and a Bachelor of Science in psychology from Idaho State University with additional coursework in substance use and case management.