Font Size


What Is Autism Spectrum Disorder (ASD)?

Autism is a complex developmental disorder that has the following three defining core features:

  1. Problems with social interactions
  2. Impaired verbal and nonverbal communication
  3. A pattern of repetitive behavior with narrow, restricted interests

A number of other associated symptoms frequently coexist with autism.

  • Most people with autism have problems using language, forming relationships, and appropriately interpreting and responding to the external world around them.
  • Autism is a behaviorally defined developmental disorder that begins in early childhood.
  • Although the diagnosis of autism may not be made until a child reaches preschool or school age, the signs and symptoms of autism may be apparent by the time the child is aged 12-18 months, and the behavioral characteristics of autism are almost always evident by the time the child is aged 3 years.
  • Language delay in the preschool years (younger than 5 years) is typically the presenting problem for more severely affected children with autism. Higher functioning children with autism are generally identified with behavioral problems when they are aged approximately 4-5 years or with social problems later in childhood.
  • Autism disorder persists throughout the person's lifetime, although many people are able to learn to control and modify their behavior to some extent.

As of May 2013, autism, along with what were formally described as Asperger's syndrome and pervasive developmental disorders were classified by the American Psychiatric Association as autism spectrum disorders (ASDs).

All of these disorders are characterized by varying degrees of problems with communication, social interaction, and atypical, repetitive behaviors.

There is a wide range of symptoms, severity, and other manifestations of these disorders. The expression of autism spectrum disorders varies widely among affected individuals. A child with significant impairment in all three of the core functioning areas (socialization, communication, and atypical, repetitive behaviors) may have a lower level-functioning autism spectrum disorder, while a child with similar problems but without delays in language development may have a higher level-functioning autism spectrum disorder.

Some people are affected with fairly mild symptoms and signs of autism. Many of these individuals learn to live independent lives. Others are more severely affected and require lifelong care and supervision.

As the following statistics indicate, autism is a common developmental disorder.

  • The number of children diagnosed with autism spectrum disorders appears to be increasing. Although there is a concern that the actual number of children with autism spectrum disorders is increasing, several factors, such as improvements in diagnostic methods and the view of autism spectrum disorders as being on a continuum, also may account for the increase.
  • Autism affects all races, ethnic groups, and socioeconomic levels.
  • Boys are more likely than girls to have autism.

There is no cure for autism; however, there is good news.

  • A generation ago, most children with autism were institutionalized. This is no longer the case and most children with this disorder live with their families.
  • Our improving understanding of autism has shown that, regardless of the severity of the condition, appropriate treatment and education can eventually help many children with autism to be integrated into their community.
  • Early diagnosis is essential for implementing appropriate treatment and education at an early age, when they can do the most good.
Medically Reviewed by a Doctor on 12/11/2015

Must Read Articles Related to Autism

Asperger's Syndrome (Asperger Syndrome, Asperger Disorder)
Asperger Syndrome Asperger syndrome, also known as Asperger's disorder, Asperger's syndrome, or AS, is a learn more >>
Seizures in Children
Seizures in Children A seizure occurs when the brain functions abnormally, and can affect different parts of the brain and body. The learn more >>
Wilderness: Seizure Seizure is a neurological condition t...learn more >>

Patient Comments & Reviews

The eMedicineHealth doctors ask about Autism:

Autism - Treatment

What treatment was effective for your autism?

Autism - Diagnosis

How was your experience with autism diagnosed?

Autism - Symptoms

What were the symptoms of your children autism?

One doctor's perspective on vaccines and autism.

Vaccinations and Autism: One Pediatrician's Perspective

Medical Author:David Perlstein, MD, FAAP
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR

When I was asked to write a Doctor's View about the Hannah Poling ruling, I hesitated initially, and then determined that it was one of my responsibilities as a pediatrician to give my opinions of the decision. Briefly, this is in response to the recent case in which the federal government ruled that Hannah Poling, a nine year old girl, was entitled to receive compensation from a federal vaccine injury fund after developing neurological delays, including signs and symptoms of autism, following administration of a number of vaccines in 2000. This decision added fire to the Blog-O-Sphere where it was seen as both a victory for anti-vaccine groups and as the Government's admission that vaccines are the cause of the increase in the incidence of Autism Spectrum Disorders. On March 6, 2008, after the Poling ruling, Dr. Julie Gerberding, Director of the Centers for Disease Control and Prevention, in response to a question about the government's ruling stated:

"Let me be very clear that government has made absolutely no statement about indicating that vaccines are a cause of autism. And that is a complete mischaracterization of the findings of the case and a complete mischaracterization of any of the science that we have at our disposal today."

First of all, as a general pediatrician working in the Bronx, and as a parent of children with medical and developmental problems, I can wholly appreciate the visceral nature of dealing with a child who is not "normal". I also want to be clear that, although I do not have child with autism, I recognize the challenges and emotional stressthat is involved in raising a child with autistic features. I would like to personally praise Hannah's parents and especially her father Dr. Jon Poling, who has been adamant about his support of immunizing children against infectious diseases.

Read What Your Physician is Reading on Medscape

Pervasive Developmental Disorder: Autism »

Autism is a condition that manifests in early childhoodand is characterized by qualitative abnormalities in social interactions, marked aberrant communication skills, and restricted repetitive and stereotyped behaviors.

Read More on Medscape Reference »

Medical Dictionary