Autism (Symptoms)

Social Deficits

Most children with autism have tremendous difficulty engaging in everyday human interaction, and even in infancy—the stage in which most babies tend to want to touch and explore other human beings—they keep to themselves and avoid eye contact. They may resist basic forms of affection and may not show anger or pleasure when the parent leaves or returns. Research has suggested that although children with ASD are attached to their parents, their expression of this attachment is unusual and difficult to read. To parents, it may seem as if their child is not attached at all. Parents who looked forward to the joys of cuddling, teaching, and playing with their child may feel crushed by this lack of the expected and typical attachment behavior.

Children with autism have difficulty understanding unspoken social cues.

Subtle social cues—whether a smile, a wink, or a grimace—may have little meaning. To a child who misses these cues, "come here" always means the same thing, whether the speaker is smiling and extending her arms for a hug or frowning and planting her fists on her hips. Without the ability to interpret gestures and facial expressions, the social world may seem bewildering.

An autistic person may also lack ability to understand things from another's perspective, making them unable to comprehend or predict other people's responses to their own actions.

Some people with autism also might have difficulty regulating their emotions; they may tend to be physically aggressive or prone to loss of control, particularly when they are frustrated or in an overwhelming environment. They may break things, pull their hair, and hurt themselves or others.

Language Deficits

Research shows that while some infants babble during their first six months, about half of the children diagnosed with autism remain mute throughout their lives. Those who are not mute may develop language skills as late as ages 5 to 9, whereas most children without autism can put together phrases and follow simple directions by age 2. Those who speak might repeat the same phrase over and over, only use single words, or be unable to combine words into logical sentences.

Some autistic children are only able to repeat what they have heard, a condition called echolalia. Children without autism also have this tendency, but the phase usually ends by the time they are 3.

Some children who are only mildly affected exhibit slight delays in language or even seem to have precocious language skills and unusually large vocabularies; however, they have great difficulty sustaining a conversation. The give and take of normal conversation is hard for them, although they often carry on a monologue on a favorite subject, giving no one else an opportunity to comment. Another frequent difficulty is the inability to understand body language, tone of voice, or phrases of speech.

People with autism tend to confuse pronouns, so the words "my," "I," and "you" all mean the same thing. If an autistic child's father asks, "What color is my shirt?" the child might respond with the color of his own shirt.

Interpreting body language of a child with autism can be difficult, as the gestures and tone of voice rarely match what the child is saying or indicate what the child is feeling. A voice that is either high-pitched and sing-song or flat and robotlike is common among children with ASD.

Without meaningful gestures or the language to make simple requests, people with ASD are at a loss to let others know what they need. As a result, they may simply grab what they want or scream. Until they are taught better ways to express their needs, ASD children do whatever they can to get through to others. As people with ASD grow up, they can become increasingly aware of their difficulties in understanding others and in being understood. As a result, they may become anxious or depressed.

Repetitive Behaviors

Many people with ASD walk on their toes or flail their arms and suddenly freeze their position. Experts call such behaviors stereotypes or self-stimulation.

People with autism, especially children, need and demand absolute consistency in their environment, many engaging in daily rituals at exactly the same time in the same place. They may get deeply angered if a cup is not in the place they left it or a pillow is on a different part of the sofa. As children, they might spend hours lining up their toy cars and trains in a certain way, rather than using them for pretend play. If someone accidentally moves one of the toys, the child may become tremendously upset.

Repetitive behavior sometimes takes the form of a persistent, intense preoccupation. For example, the child might be obsessed with learning all about vacuum cleaners, train schedules, or lighthouses. Often there is great interest in numbers, symbols, or science topics. A child's ability to play is limited by these compulsive behaviors. For the child with ASD there is little imaginative or pretend play. They don't imitate the actions of others, and they prefer solitary or ritualistic play.

Problems That May Accompany ASD

Sensory Perception Issues

Autistic children tend to be incapable of accurately taking in sensory perception or merging the stimuli into a coherent picture, leading to a baffling experience of the world. Many children with autism are highly attuned or even painfully sensitive to certain sounds, textures, tastes, or smells. Some children find the smell of a certain food cooking so distracting that it becomes their entire focus. For others, a gentle pat on the head may be terrifying. Some sounds—a vacuum cleaner, a ringing telephone, a sudden storm, even the sound of waves lapping the shoreline—will cause these children to cover their ears and scream.

The brain of an autistic child seems unable to balance the senses appropriately. This can cause some children to be oblivious to extreme cold; others may fall and break an arm yet never cry. Another may bash his head against a wall and not wince, but a light touch will make him scream with alarm. In some people, the senses are scrambled: A child may cover her ears to avoiding hearing a certain color that she experiences as sound.

Mental Retardation

Many children with ASD have some degree of mental impairment. When tested, some areas of ability may be normal, while others may be especially weak. For example, a child with ASD may do well on the parts of the test that measure visual skills but earn low scores on the language subtests.


About one-fourth of children with autism develop seizures either in early childhood or adolescence. These can range from brief blackouts to full-blown body convulsions. In most cases, seizures can be controlled with medication.

Fragile X

Fragile X syndrome (the most commonly inherited form of mental retardation, named for a defective piece of the X chromosome that appears pinched and fragile under a microscope) is found in 2 percent to 5 percent of people with autism. People who inherit this genetic code are more likely to have mental retardation and many symptoms of autism along with unusual physical features that are not typical of autism. It is important to have a child with ASD checked for fragile X, especially if the parents are considering having another child. For unknown reasons, if a child with ASD also has fragile X, there is a 50 percent chance that boys born to the same parents will also have the syndrome. Other members of the family who may be contemplating having a child may wish to be checked for the syndrome.

Tuberous Sclerosis

There is a relationship between autism and tuberous sclerosis, a genetic condition that causes abnormal tissue growth in the brain and problems in other organs. While tuberous sclerosis occurs less than once in 10,000 births, about a fourth of those affected are also autistic. Scientists are exploring genetic conditions such as fragile X and tuberous sclerosis to see why they so often coincide with autism.

Diagnosing Autism

For a diagnosis of autism, problems in at least one of the areas of communication, socialization, or restricted behavior must be present before the age of 3. The diagnosis requires a two-stage process. The first stage involves developmental screening during "well child" checkups; the second stage entails a comprehensive evaluation by a multidisciplinary team.

Parents may notice their baby seems different from birth, unresponsive to toys and people or focusing intently on one item for oddly long periods. Yet autistic signs can also turn up in a toddler who had previously seemed normal: A generally healthy, responsive baby suddenly becomes violent or withdrawn. Years may pass before a parent seeks a diagnosis, wishing instead to believe that everything is all right, which only delays appropriate treatment.

Reviewing family videotapes, photos, and baby albums can help parents remember when each behavior was first noticed and when the child reached certain developmental milestones.

Several screening instruments have been developed to quickly gather information about a child's social and communicative development within medical settings. Among them are the Checklist of Autism in Toddlers (CHAT), the modified Checklist for Autism in Toddlers (M-CHAT), the Screening Tool for Autism in Two-Year-Olds (STAT), and the Social Communication Questionnaire (SCQ; for children 4 years of age and older). Some screening instruments rely solely on parent responses to a questionnaire, and some rely on a combination of parent reports and observation. Key items on these instruments that appear to differentiate children with autism from other groups before the age of 2 include pointing and pretend play.

A doctor may also consider other conditions with the same symptoms as autism, such as Rett's disorder or Asperger's syndrome. Rett's disorder is a progressive brain disease that only affects girls but, similar to autism, produces repetitive hand movements and leads to loss of language and social skills. Children with Asperger's syndrome have repetitive behaviors, severe social problems, and clumsy movements, yet their language and intelligence are usually intact.

During the last few years, screening instruments have been devised to screen for Asperger's syndrome and higher-functioning autism. The Autism Spectrum Screening Questionnaire (ASSQ), the Australian Scale for Asperger's Syndrome, and the Childhood Asperger Syndrome Test (CAST), are some of the instruments that are reliable for identification of school-age children with Asperger's syndrome or higher-functioning autism. These tools concentrate on social and behavioral impairments in children without significant language delay.

In order to rule in or rule out ASD or other developmental disorders, the second phase of diagnosis must be comprehensive, including neurological and genetic assessments along with in-depth cognitive and language testing. These include the Autism Diagnosis Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS-G). The ADI-R is a structured interview that contains over 100 items and is conducted with a caregiver. It concentrates on four main factors—communication, social interaction, repetitive behaviors, and age-of-onset symptoms. The ADOS-G is an observational measure used to press for socio-communicative behaviors that are often delayed, abnormal, or absent in children with ASD.

Another instrument often used by professionals is the Childhood Autism Rating Scale (CARS). It aids in evaluating the child's body movements, adaptation to change, listening response, verbal communication, and relationship to people. It is suitable for use with children over 2 years of age. The examiner observes the child and also obtains relevant information from the parents. The child's behavior is rated on a scale based on deviation from the typical behavior of children of the same age.

Two other tests that should be used to assess any child with a developmental delay: A formal audiologic hearing evaluation should be administered to determined if there is an actual hearing loss, and a lead screening should be conducted. Children with an autistic disorder usually have elevated blood lead levels.

Receiving a diagnosis of autism can be devastating, but be sure to ask questions of the evaluation team and get recommendations for further steps as well as the names of professionals who can answer other questions that might come up.

Autism. Last reviewed 12/31/1969
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