What is Autism Spectrum Disorder (ASD)?

How do you know if someone has autism?

Signs, Symptoms, & Characteristics of ASD

Autism Spectrum Disorders (ASDs) usually begin before the age of three and last throughout a person’s life, although the symptoms may improve over time. Some children with an ASD show hints of future problems within the first few months of life. In others, symptoms may not be visible until 24 months or later. Some children with an ASD seem to develop normally until around 18-24 months of age and then they stop gaining new skills, or they lose the skills they once had. Studies have shown that one-third to half of parents of children with an ASD noticed a problem before their child’s first birthday, and nearly 80%-90% saw problems by 24 months of age.

People With an ASD might:
  • Not respond to his or her name by 12 months
  • Not point at objects to show interest (e.g. point at an airplane flying over) by 14 months
  • Not play “pretend” games (e.g. pretend to “feed” a doll) by 18 months
  • Avoid eye contact and want to be alone
  • Have trouble understanding other people’s feelings or talking about their own feelings
  • Have delayed speech and language skills
  • Repeat words and phrases over and over (echolalia)
  • Give unrelated answers to questions
  • Get upset by minor changes
  • Have obsessive interests
  • Flap their hands, rock their bodies or spin in circles
  • Have unusual reactions to the way things sound, smell, taste, look or feel

It is important to note that some people without an ASD might also have some of these symptoms. However, for people with an ASD, the impairments make life very challenging.

Social Skills

Social issues are one of the most common symptoms in all of the types of ASD. People with an ASD do not have just social “difficulties” like shyness. The social issues they have cause serious problems in everyday life.
Examples of social issues related to ASDs:

  • No babbling, pointing or meaningful gestures by 1 year of age
  • Apparent lack of response to sounds or voices and name being called by 12 months of age
  • No one-word communications by 16 months of age
  • No two-word phrases by 2 years of age
  • Loss of language or social skills
  • Inability to play appropriately with toys
  • Unusual attachment to one particular toy or object
  • Has flat or inappropriate facial expressions
  • Does not understand personal space boundaries
  • Avoids or resists physical contact
  • Is not comforted by others during distress
  • Has trouble understanding other people’s feelings or talking about own feelings
  • Avoids eye-contact
  • Prefers to play alone
  • Does not share interests with others
  • Only interacts to achieve a desired goal

Typical infants are very interested in the world and people around them. By the first birthday, a typical toddler interacts with others by looking people in the eye, copying words and actions, and using simple gestures such as clapping and waving “bye bye”. Typical toddlers also show interests in social games like peek-a-boo and pat-a-cake. But a young child with an ASD might have a very hard time learning to interact with other people.

Some people with an ASD might not be interested in other people at all. Others might want friends, but not understand how to develop friendships. Many children with an ASD have a very hard time learning to take turns and share—much more so than other children. This can make other children not want to play with them.
People with an ASD might have problems with showing or talking about their feelings. They might also have trouble understanding other people’s feelings. Many people with an ASD are very sensitive to being touched and might not want to be held or cuddled. Self-stimulatory behaviors (e.g., flapping arms over and over) are common among people with an ASD. Anxiety and depression also affect some people with an ASD. All of these symptoms can make other social problems even harder to manage.

Communication

Each person with an ASD has different communication skills. Some people can speak well. Others can’t speak at all or only very little. About 40% of children with an ASD do not talk at all. About 25%–30% of children with an ASD have some words at 12 to 18 months of age and then lose them. Others might speak, but not until later in childhood.
Examples of communication issues related to ASDs:

  • Delayed speech and language skills
  • Repeats words or phrases over and over (echolalia)
  • Reverses pronouns (e.g., says “me” instead of “I”)
  • Gives unrelated answers to questions
  • Does not point or respond to pointing
  • Uses few or no gestures (e.g., does not wave goodbye)
  • Talks in a flat, robot-like, or sing-song voice
  • Does not pretend in play (e.g., does not pretend to “feed” a doll)
  • Does not understand jokes, sarcasm, or teasing

People with an ASD who do speak might use language in unusual ways. They might not be able to put words into real sentences. Some people with an ASD say only one word at a time. Others repeat the same words or phrases over and over. Some children repeat what others say, a condition called echolalia. The repeated words might be said right away or at a later time. For example, if you ask someone with an ASD, “Do you want some juice?” he or she might repeat “Do you want some juice?” instead of answering your question. Although many children without an ASD go through a stage where they repeat what they hear, it normally passes by three years of age. Some people with an ASD can speak well but might have a hard time listening to what other people say.

People with an ASD might have a hard time using and understanding gestures, body language, or tone of voice. For example, people with an ASD might not understand what it means to wave goodbye. Facial expressions, movements, and gestures may not match what they are saying. For instance, people with an ASD might smile while saying something sad.

People with an ASD might say “I” when they mean “you,” or vice versa. Their voices might sound flat, robot-like, or high-pitched. People with an ASD might stand too close to the person they are talking to, or might stick with one topic of conversation for too long. They might talk a lot about something they really like, rather than have a back-and-forth conversation with someone. Some children with fairly good language skills speak like little adults, failing to pick up on the “kid-speak” that is common with other children.

Unusual Interests and Behaviors

Many people with an ASD have unusual interest or behaviors.
Examples of unusual interests and behaviors related to ASDs:
• Lines up toys or other objects
• Plays with toys the same way every time
• Likes parts of objects (e.g., wheels)
• Is very organized
• Gets upset by minor changes
• Has obsessive interests
• Has to follow certain routines
• Flaps hands, rocks body, or spins self in circles

Repetitive motions are actions repeated over and over again. They can involve one part of the body, the entire body, or even an object or toy. For instance, people with an ASD might spend a lot of time repeatedly flapping their arms or rocking from side to side. They might repeatedly turn a light on and off or spin the wheels of a toy car. These types of activities are known as self-stimulation or “stimming.”
People with an ASD often thrive on routine. A change in the normal pattern of the day—like a stop on the way home from school—can be very upsetting to people with an ASD. They might “lose control” and have a “melt down” or tantrum, especially if in a strange place.

Some people with an ASD also may develop routines that might seem unusual or unnecessary. For example, a person might try to look in every window as he or she walks by a building or might always want to watch a video from beginning to end, including the previews and the credits. Not being allowed to do these types of routines might cause severe frustration and tantrums.

Other Symptoms

Some people with an ASD have other symptoms. These might include:
• Hyperactivity (very active)
• Impulsivity (acting without thinking)
• Short attention span
• Aggression
• Causing self injury
• Temper tantrums
• Unusual eating and sleeping habits
• Unusual mood or emotional reactions
• Lack of fear or more fear than expected
• Unusual reactions to the way things sound, smell, taste, look, or feel

 

People with an ASD might have unusual responses to touch, smell, sounds, sights, taste, and feel. For example, they might over- or under-react to pain or to a loud noise. They might have abnormal eating habits. For instance, some people with an ASD limit their diet to only a few foods. Others might eat nonfood items like dirt or rocks (this is called pica). They might also have issues like chronic constipation or diarrhea.

People with an ASD might have odd sleeping habits. They also might have abnormal moods or emotional reactions. For instance, they might laugh or cry at unusual times or show no emotional response at times you would expect one. In addition, they might not be afraid of dangerous things, and they could be fearful of harmless objects or events.

Diagnostic and Statistical Manual of Mental Disorders: DSM IV

Diagnostic Criteria

  1. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive, see text):
    1.       Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.
    2.       Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
    3.       Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers.

Specify current severity:
Severity is based on social communication impairments and restricted repetitive patterns of behavior

  1. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive; see text):
  2. Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
  3. Insistence on sameness, inflexible adherence to routines, or ritualized patterns or verbal nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat food every day).
  4. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g, strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interest).
  5. Hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

Specify current severity:

Severity is based on social communication impairments and restricted, repetitive patterns of behavior.

  1. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life).
  2. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.
  3. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level.

Note: Individuals with a well-established DSM-IV diagnosis of autistic disorder, Asperger’s disorder, or pervasive developmental disorder not otherwise specified should be given the diagnosis of autism spectrum disorder. Individuals who have marked deficits in social communication, but whose symptoms do not otherwise meet criteria for autism spectrum disorder, should be evaluated for social (pragmatic) communication disorder.

Specify if:
With or without accompanying intellectual impairment
With or without accompanying language impairment
Associated with a known medical or genetic condition or environmental factor
(Coding note: Use additional code to identify the associated medical or genetic condition.)
Associated with another neurodevelopmental, mental, or behavioral disorder
(Coding note: Use additional code[s] to identify the associated neurodevelopmental, mental, or behavioral disorder[s].)
With catatonia (refer to the criteria for catatonia associated with another mental disorder, pp. 119-120, for definition) (Coding note: Use additional code 293.89 [F06.1] catatonia associated with autism spectrum disorder to indicate the presence of the comorbid catatonia.)

 

Who is Affected

ASDs occur in all racial, ethnic, and socioeconomic groups, but are four times more likely to occur in boys than in girls. CDC estimates that between about 1 in 80 and 1 in 240, with an average of 1 in 110, children in the United States have an ASD.

More people than ever before are being diagnosed with an ASD. It is unclear exactly how much of this increase is due to a broader definition of ASDs and better efforts in diagnosis. However, a true increase in the number of people with an ASD cannot be ruled out. We believe the increase in ASD diagnosis is likely due to a combination of these factors.

Within the past decade, CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network has been estimating the number of people with an ASD in the U.S. We have learned a lot about how many children in the U.S. have an ASD. It will be important to use the same methods to track how the number of people with an ASD is changing over time in order to learn more about the disorders.

Early Intervention Services

Research shows that early intervention treatment services can greatly improve a child’s development. Early intervention services help children from birth to 3 years old (36 months) learn important skills. Services include therapy to help the child talk, walk, and interact with others. Therefore, it is important to talk to your child’s doctor as soon as possible if you think your child has an ASD or other developmental problem.

Even if your child has not been diagnosed with an ASD, he or she may be eligible for early intervention treatment services. The Individuals with Disabilities Education Act (IDEA) says that children under the age of 3 years (36 months) who are at risk of having developmental delays may be eligible for services. These services are provided through an early intervention system in your state. Through this system, you can ask for an evaluation.