What is autism spectrum disorder?

Autism spectrum disorder (ASD) describes a wide range of complex brain development disorders that can strike children at an early age. The spectrum of autism disorders includes autistic disorder, Asperger’s syndrome and pervasive developmental disorders. Those diagnosed with ASD are also assessed for levels of intellectual disability and language impairment. But people with ASD can also excel in visual skills, music, math and art. Additionally, ASD may affect an individual’s physical health, triggering digestive issues and problems sleeping. The developmental disorders occur in every racial and ethnic group and across all socioeconomic levels. ASD affects both sexes, but boys are more likely than girls to develop ASD.

What are the symptoms of autism spectrum disorder?

When compared with their peers, children with ASD may seem different. Common signs of ASD include not babbling or pointing by age 1, not saying single words by age 16 months or two-word phrases by age 2. In addition, children with ASD may not respond when their name is called, have difficulty paying attention, exhibit poor eye contact, are unable to play well with other children, won’t smile or are unresponsive to social interaction. Also, many kids with the disorder engage in repetitive and obsessive patterns of behavior, such as rocking, twirling or flapping their arms.

Children with ASD often find it hard to talk about their feelings and don’t understand the feelings of others, so they may prefer to be alone. At an early age, these kids may also suffer from a delayed development of their motor skills, which can affect their dexterity and ability to handle tasks requiring hand-eye coordination. As they become older, children with ASD may find it hard to learn how to sit up, walk, use eating utensils or hold a pen or pencil to write.

The verbal abilities of people with ASD can range from not speaking at all to being fluent but often awkward and inappropriate. In addition, some kids with ASD repeat words and phrases and offer unrelated answers to questions. Many times these children don’t understand such nonverbal cues as gestures, body language or tone of voice. They may also speak in a monotone and can seem as if they’re devoid of emotion. Kids with ASD generally thrive on routine and may respond to any changes in their lives with emotional outbursts or anger.

What causes autism spectrum disorder?

After many years of not knowing what caused ASD, researchers now believe that most often it’s environmental factors and gene mutations that trigger the disorder. According to experts, if a child is predisposed to ASD, there are a variety of risk factors that can increase the likelihood that he or she will develop the disorder. Some of these include older parents conceiving a child, a mother being ill during pregnancy and complications that can occur at this time, especially when babies’ brains are deprived of oxygen.

Currently, researchers are studying associations between the immune system and ASD. Scientists are exploring this possibility because many people with the disorder show signs of inflammation—an immune response the body mounts to protect itself from invaders—in the brain. In addition, findings show many kids with ASD have malfunctions in their immune systems.

At one point, people expressed concern that ASD might be linked to vaccines recommended for children. But studies have shown that there is no link between receiving vaccines and developing ASD, says the Centers for Disease Control and Prevention. What’s more, researchers have also found no connection between ingredients used in vaccines and the condition.

How is autism spectrum disorder diagnosed?

Currently, there is no medical test for ASD. Instead, specially trained doctors and psychologists use behavioral evaluations specific for ASD. One evaluation is a questionnaire called the Modified Checklist of Autism in Toddlers, or M-CHAT.

These questions are designed to elicit answers that help doctors decide whether a child should be further evaluated by a specialist, such as a developmental pediatrician, neurologist, psychiatrist or psychologist. This multi-disciplinary approach to a diagnostic assessment ensures that parents can learn as much as possible about their children’s individual strengths and weaknesses related to ASD.

Specialists may also use comprehensive screening tests to assess and evaluate a child’s physical and cognitive development.

For ASD diagnoses made later in life, specialists interview individuals and make personal observations to determine whether they’re suffering from social and emotional problems.

How is autism spectrum disorder treated?

Although there’s no cure for ASD, therapies and educational and behavioral interventions can help alleviate and improve specific symptoms of the disorder.

For kids with ASD, doctors have successfully used early interventions to help children develop positive skills to improve social interaction and boost their ability to understand and use language in appropriate ways. Meanwhile, other family members can benefit from counseling to help them cope with the challenges of living with a child with ASD.

In addition, medications can help treat related symptoms of ASD, such as anxiety, depression, obsessive-compulsive disorder and severe behavioral problems. The best treatment plan customizes all these approaches to address the needs of each individual with ASD.

For many children with ASD who engage in these treatments, symptoms of the disorder can improve. When they transition into adolescence and adulthood, doctors may need to tweak their therapy plan.

Usually, as people with ASD age, they continue to need services and a supportive environment. Depending on the severity of their ASD, these individuals can work successfully and live on their own.

Last Reviewed: January 19, 2022