Autism Spectrum Disorder (ASD)


Our nation’s special education law, the Individuals with Disabilities Act (IDEA) defines Autism as…

“… a developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age three, that adversely affects a child’s educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. [The term] autism does not apply if a child’s educational performance is adversely affected primarily because the child has an emotional disturbance, as defined in paragraph (c)(4) of [IDEA]. A child who manifests the characteristics of autism after age three could be identified as having autism if the criteria are able to be satisfied.”

[34 Code of Federal Regulations §300.8(c)(i, ii, and iii).]

Autism spectrum disorder (ASD) is a developmental disability that can cause significant social, communication and behavioral challenges. There is often nothing about how people with ASD look that sets them apart from other people, but people with ASD may communicate, interact, behave, and learn in ways that are different from most other people. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged. Some people with ASD need a lot of help in their daily lives; others need less.

A diagnosis of ASD now includes several conditions that used to be diagnosed separately: autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome. These conditions are now all called autism spectrum disorder.

(Center for Disease Control and Prevention, CDC, 2019)

When the term autism is used in this document, it refers to the current and broader diagnosis of autism spectrum disorder (ASD), an umbrella term that merged four previous diagnostic categories. (See APA, 2013 and DSM-5 below). Although person-first language is preferred by some organizations and individuals with disabilities (e.g., person with ASD; person with an intellectual disability), other individuals may prefer identity-first language to emphasize the disability as an integral and important part of themselves. In the latter case, a person may refer to themselves as autistic. Also, some individuals may still identify themselves by using separate terms such as Asperger Syndrome or Autistic. (Authors, 2019)


In 2013, the American Psychiatric Association released the most updated version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Full diagnostic criteria for Autism Spectrum Disorder (ASD) and severity level classifications according to the DSM-5 are available through the CDC Website below.

(CDC, 2019)


About 1 in 59 children has been identified with Autism Spectrum Disorder according to estimates from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. Diagnoses are about four times more common among boys (1 in 37) than among girls (1 in 151). Reliable diagnoses can be made as early as age 2, but most children are diagnosed with ASD after age 4. ASD is reported to occur in all racial, ethnic, and socioeconomic groups although minority groups tend to be diagnosed later and less often. Potential barriers to identification in these populations may include stigma, lack of access to healthcare services, and a non-English primary language.

Parents who have a child with ASD have a 2 to 18 percent chance of having a second child who is also affected. Studies have suggested that among identical twins, if one child has autism, the other will be affected about 36-95 percent of the time. In non-identical twins, if one child has autism, then the other is affected about 31 percent of the time.

A large percentage of children with ASD (44%) have above average intelligence (IQ > 85), 25% are in the borderline range (between 85-71) and only 31% are assessed as having an intellectual disability (IQ < 70). An estimated one-third of people with autism are nonverbal. A large number of individuals with autism wander or bolt from safety; drowning remains a leading cause of death and accounts for approximately 90 percent of deaths associated with wandering or bolting by children ages 14 and younger.

(Autism Speaks, 2019)
(CDC, 2019)


The timing and intensity of autism’s early signs vary widely. Some infants show hints in their first months. In others, behaviors become obvious as late as age 2 or 3. Not all children with autism show all the signs. Many children who don’t have autism show a few. This is why professional evaluation is crucial.

At any age, the following may indicate that a child is at risk for an autism spectrum disorder:

  • Loss of previously acquired speech, babbling or social skills
  • Avoidance of eye contact
  • Persistent preference for solitude
  • Difficulty understanding people’s feelings
  • Delayed language development
  • Persistent repetition of words or phrase (echolalia)
  • Resistance to minor changes in routine or surroundings
  • Restricted interests
  • Repetitive behaviors (flapping, rocking, spinning, etc.)
  • Unusual and intense reaction to sounds, smells, tastes, textures, lights and/or colors

(Autism Speaks, 2019)


We do not know all of the causes of ASD. However, we have learned that there are likely many causes for multiple types of ASD. There may be many different factors that make a child more likely to have an ASD, including environmental and genetic factors.

  • Most scientists agree that genes are one of the risk factors that can make a person more likely to develop ASD.
  • Children who have a sibling with ASD are at a higher risk of also having ASD.
  • ASD tends to occur more often in people who have certain genetic or chromosomal conditions, such as fragile X syndrome or tuberous sclerosisexternal icon.
  • When taken during pregnancy, the prescription drugs valproic acid and thalidomide have been linked with a higher risk of ASD.
  • There is some evidence that the critical period for developing ASD occurs before, during, and immediately after birth.
  • Children born to older parents are at greater risk for having ASD.

CDC, 2019

No evidence has been found to show a link between autism and MMR vaccine, thimerosal, multiple vaccines given at once, fevers or seizures.

(American Academy of Pediatrics, 2019)


Diagnosing ASD can be difficult since there is no medical test, like a blood test, to diagnose the disorder. Doctors need to look at the child’s behavior and development to make a diagnosis.

ASD can sometimes be detected at 18 months or younger, but by age 2, a diagnosis of a child by an experienced professional can be considered very reliable. A final diagnosis, however, may not be made until the child is older.

Diagnosing an ASD takes two steps:

  1. Developmental Screening
  2. During developmental screening, the doctor might ask the parent some questions or talk and play with the child during an exam to see how she learns, speaks, behaves, and moves. A delay in any of these areas could be a sign of a problem, or maybe not. Continued observations and screening are important. All children can be screened for developmental delays and disabilities during regular well-child doctor visits (9 months, 18 months, 24/30 months). Additional screening might be needed if a child is at high risk for ASD (e.g., having a sibling with ASD) or if behaviors sometimes associated with ASD are present. If a child’s doctor does not routinely check a child with this type of developmental screening test, the parent or guardian needs to ask that it be done.
  3. Comprehensive Diagnostic Evaluation
  4. This thorough review may include looking at the child’s behavior and development and interviewing the parents. It may also include a hearing and vision screening, genetic testing, neurological testing, and other medical testing. In some cases, the primary care doctor might choose to refer the child and family to a specialist for further assessment and diagnosis.

(CDC, 2019)


There are no medications that can cure ASD or treat the core symptoms. However, there are medications that can help some people with ASD function better. For example, medication might help manage high energy levels, inability to focus, depression, or seizures.

Medications might not affect all children in the same way. It is important to work with a health care professional who has experience in treating children with ASD. Parents and health care professionals must closely monitor a child’s progress and reactions while he or she is taking a medication to be sure that any negative side effects of the treatment do not outweigh the benefits.

It is also important to remember that children with ASD can get sick or injured just like children without ASD. Regular medical and dental exams should be part of a child’s treatment plan. Often it is hard to tell if a child’s behavior is related to the ASD or is caused by a separate health condition. For instance, head banging could be a symptom of the ASD, or it could be a sign that the child is having headaches. In those cases, a thorough physical exam is needed. Monitoring healthy development means not only paying attention to symptoms related to ASD, but also to the child’s physical and mental health, as well.

According to reports by the American Academy of Pediatrics and the National Research Council, behavior and communication approaches that help children with ASD are those that provide structure, direction, and organization for the child in addition to family participation.

A notable treatment approach for people with an ASD is called applied behavior analysis (ABA). ABA has become widely accepted among health care professionals and used in many schools and treatment clinics. ABA encourages positive behaviors and discourages negative behaviors in order to improve a variety of skills. The child’s progress is tracked and measured. (See more information about ABA at Among other approaches are occupational therapy, sensory integration therapy, and speech therapy.

(CDC, 2019)


In addition to academic structure, special education programs for students with ASDs focus on improving communication, social, academic, behavioral and daily living skills. Behavior and communication problems that interfere with learning often require the assistance of a professional who is particularly knowledgeable in the ASD field, professionals that can help develop and implement a plan to be carried out at home and school.

The classroom environment should be structured so that it provides consistency and predictability. The probability of successful learning experiences for many students, including those with ASDs, can increase when information is presented visually as well as verbally, and when students have increased opportunities for structured interactions with classmates. Interactions with typically developing children may be difficult for children with ASDs, but it is an important strategy for academic, social, and emotional growth. Since consistency and continuity are important for learning, there is a higher probability that students will be more successful and retain what they have learned in school when parents are involved in the development of their child’s program and when learning activities, experiences, and strategies are continued in the child’s home and community environments, to the extent possible.

A number of published articles and web sites provide information regarding classrooms strategies. One center, the IRIS Center, in partnership with Peabody College and Vanderbilt University, has created interactive modules for educators with helpful information about ASD including current evidence-based practices and strategies. Explore the many sites and resources for teachers on the websites for organizations and resources below.

Innovative Resources Instructional Success Center (IRIS, 2019)

Part 1: An Overview for Educators
Part 2: Evidence-based practices


Autism Navigator 
1400 Village Square Blvd. 
Suite #3-157 
Tallahassee, FL 32312-1231 
Phone: 1 (844) 427-3457

Autism Navigator is a unique collection of web-based tools and courses developed to bridge the gap between science and community practice. We have integrated the most current research into a highly interactive web platform with extensive video footage to illustrate effective evidence-based practice. The video clips come from the unparalleled library of video footage from federally funded research projects at the Autism Institute at Florida State University. Early diagnosis and intervention has lifetime consequences for children with ASD and their families. By interfacing professional courses for primary care physicians and early intervention providers with information and support for families and communities using technology-supported learning, Autism Navigator can create an integrated, effective, cost-efficient, community-viable system of service delivery for children with ASD and their families.

Autism Research Institute 
4182 Adams Avenue 
San Diego, CA 92116 
Phone: (833) 281-7165

The Autism Research Institute (ARI), a non-profit organization, was established in 1967. ARI is primarily devoted to conducting research, and to disseminating the results of research, on the causes of autism and on methods of preventing, diagnosing and treating autism and other severe behavioral disorders of childhood. We provide information based on research to parents and professionals throughout the world.

Autism Science Foundation 
NYC Office 
106 West 32nd Street, Suite #182 
New York, NY 10001 
Phone: (914) 810-9100 
Scarsdale Office 
3 Continental Road 
Scarsdale, NY 10583

The Autism Science Foundation is a nonprofit corporation whose mission is to support autism research by providing funding and other assistance to scientists and organizations conducting, facilitating, publicizing, and disseminating autism research. The organization also provides information about autism to the general public and serves to increase awareness of autism spectrum disorders and the needs of individuals and families affected by autism.

Autism Society (ASA) 
4340 East-West Hwy, Suite 350 
Bethesda, Maryland 20814 
Phone: 1(800) 328-8476

Since 1965, the Society has grown from a handful of parents, into the leading source of information, research and reference on autism. ASA is the oldest and largest grassroots organization within the autism community. ASA is dedicated to increasing public awareness about autism and the day-to-day issues faced by individuals with autism, their families, and the professionals with whom they interact. The Society and its chapters share a common mission of providing information and education, and supporting research and advocating for programs and services for the autism community. In addition to their national office, ASA has many local branches throughout the country. Use the website to identify an ASA chapter in your area.

Autism Speaks 
Autism Speaks New York Office 
1 East 33rd Street, 4th Floor 
New York, NY 10016 
Phone: (646) 385-8500 
Fax: (212) 252-8676

Autism Response Team 
Phone: (888) 288-4762

In 2005, Suzanne and Bob Wright co-founded Autism Speaks, inspired by their grandson who was diagnosed with autism. Guided by the Wright’s leadership and vision, Autism Speaks has grown in to the world’s leading autism science and advocacy organization. Autism Speaks is dedicated to promoting solutions, across the spectrum and throughout the lifespan, for the needs of individuals with autism and their families through advocacy and support; increasing understanding and acceptance of people with autism spectrum disorder; and advancing research into better causes and better interventions for autism spectrum disorder and related conditions.

Autism Spectrum Education Network (ASPEN) 
9 Aspen Circle 
Edison, NJ 08820 USA 
Phone: (732) 321-0880

ASPEN provides families and individuals whose lives are affected by Autism Spectrum Disorders and nonverbal learning disabilities with education and the issues surrounding the disorders, support in knowing that they are not alone, help in achieving their maximum potential, and advocacy in the areas of appropriate educational programs, medical research funding, adult issues and increased public awareness and understanding.

National Autism Association 
One Park Avenue, Suite 1 
Portsmouth, RI 02871 
Phone: (Toll free) (877) 622-2884 
Fax: (401) 293-5342

The mission of the National Autism Association is to respond to the most urgent needs of the autism community, providing real help and hope so that all affected can reach their full potential. This mission is achieved through advocacy, research, education, access to tools and resources, and promotion of thoughtful awareness.

Last modified December 2019.