Autism, or autism spectrum disorder (ASD), is a group of developmental disorders that can cause social, communication, and behavioral problems. These issues vary in severity between individuals. Autism spectrum disorder is an umbrella disorder that encompasses three formerly separate conditions:
- autistic disorder
- pervasive developmental disorder, not otherwise specified (PDD-NOS)
- Asperger syndrome
According to the Centers for Disease Control and Prevention (CDC), about 1 in 68 children in the United States had ASD in 2012. Autism spectrum disorder occurs in all racial, ethnic, and socioeconomic groups. It’s about four to five times more common among boys than girls. There’s no known cure for ASD and doctors haven’t discovered exactly what causes it. There may be many different factors that make a child more likely to have ASD, including environmental, biological, and genetic factors.
The early signs and symptoms of autism vary widely. Some children with ASD only have mild symptoms, and others have severe behavioral problems. However, every child with autism experiences problems with one or more of the following:
- communication (verbal and nonverbal)
- social interaction
- repetitive behaviors
Infants are usually very interested in the world and people around them. A child with ASD might not be interested or have difficulty interacting with the world around them.
A child may show early symptoms of ASD if they:
- develop language skills late
- don’t point at objects or people or wave goodbye
- don’t track people with their eyes
- show a lack of responsiveness
- don’t imitate facial expressions
- don’t reach out to be picked up
- run into or close to walls
- want to be alone
- don’t play make-believe games (e.g., feeding a doll)
- have obsessive interests
- cause injury to themself
- have temper tantrums
- display unusual reactions to the way things smell or taste
Doctors usually diagnose ASD in early childhood. However, because the symptoms and severity of the disorder vary greatly, and the cause of the disorder has not yet been found, autism spectrum disorder can often be difficult to diagnose.
At present, there’s no official test for diagnosing autism. A parent or doctor may notice early indications of ASD in an infant. A team of specialists and experts will usually make an official diagnosis of ASD.
Toddlers usually like to interact with people and the environment they live in. Parents are typically the first to notice that their child is showing atypical behavior. Parents should be aware of the early warning signs of autism, and they should share any concerns with a doctor. Some of the early indicators of ASD include:
- not making eye contact
- not responding to their name
- not babbling by 1 year of age
- not smiling or showing joyful expressions by 6 months of age
- not gesturing, like pointing, showing, or waving by 1 year of age
- not uttering meaningful phrases by 2 years of age
- losing speech or social skills
If you think your child might have ASD or you notice that your child plays, learns, speaks, or acts in unusual ways, share your concerns with your child’s doctor.
Starting from birth, your doctor will screen your child for developmental disorders during routine and regular visits. If you’re concerned about your child’s development, your doctor may refer you to a specialist, especially if a sibling or other family member has ASD. The specialist will conduct tests to determine if there’s a physical reason for the observed behaviors (such as a hearing test to evaluate for deafness/difficulty hearing). They’ll also use other screening tools for autism, such as the Modified Checklist for Autism in Toddlers.
According to the National Institutes of Health (NIH), the checklist is an updated screening tool that parents fill out. It helps determine a child’s risk of having autism as low, medium, or high. The test is free and consists of 20 questions.
If the test indicates that your child has a high risk for ASD, your child will receive a more comprehensive diagnostic evaluation. If your child is at medium risk, follow-up questions may be necessary to help definitively classify the results.
Comprehensive behavioral evaluation
The next step in autism diagnosis is a complete physical and neurologic examination. This may involve a team of specialists. The specialists may include:
- developmental pediatricians
- child psychologists
- child neurologists
- speech and language pathologists
- occupational therapists
The evaluation may also include screening tools. There are many different developmental screening tools. No single tool can diagnose autism. Rather, a combination of many tools is necessary for an autism diagnosis. Some examples of screening tools include:
- Ages and Stages Questionnaires (ASQ)
- Autism Diagnostic Observation Schedule (ADOS)
- Childhood Autism Rating Scale (CARS)
- Autism Diagnostic Observation Schedule—Generic (ADOS-G)
- Pervasive Developmental Disorders Screening Test—Stage 3
- Parents’ Evaluation of Developmental Status (PEDS)
- Gilliam Autism Rating Scale
- Screening Tool for Autism in Toddlers and Young Children (STAT)
There are also specific screening tools available for Asperger syndrome. Asperger syndrome typically involves difficulty with social and communication skills. Particular screening tools include:
- Autism Spectrum Screening Questionnaire (ASSQ)
- Childhood Asperger Syndrome Test (CAST)
According to the , the new edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-V) also offers standardized criteria to help diagnose ASD.
Genes are made of DNA. DNA instructs our bodies on how to grow and develop properly. Genetic testing can find changes in a person’s DNA associated with specific disorders or conditions. It can help diagnose a genetic disease. It can also help determine the risk that other family members have the same condition or can pass it to future generations.
Some laboratories can test for some of the biomarkers believed to be indicators for ASD. They look for the most common known genetic contributors to ASD. An abnormal result on one of these genetic tests means that genetics probably contributed to the presence of ASD. A normal result only means that a specific genetic contributor has been ruled out. It means the cause is still unknown and your child will need more testing.
Diagnosing ASD early and accurately is very important. Early intervention and treatment can greatly reduce the challenges your child may experience. It also gives them the best possibility of independence. If doctors find that your child’s ASD is due to a genetic cause, inform your family members so that they can receive counseling on the disorder.
Customizing treatment to meet your child’s individual needs is most successful. A team of specialists, teachers, therapists, and doctors should design a program for each individual child. In general, the earlier a child begins treatment, the better their long-term outlook.