Autism spectrum disorder (ASD) is a neurological and developmental condition marked by behaviors that can interfere with everyday function and create challenges for communication and social engagement. It can range in severity from mild to disabling.
ASD refers to a number of developmental conditions and disorders that used to be diagnosed separately, including autism, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome.
Children diagnosed with autism by age 8
More boys diagnosed than girls
Age in childhood when it first appears
Researchers are not sure what causes autism, but they believe genetic and environmental factors play a role. Risk factors can include having older parents or a sibling with ASD, genetic or chromosomal conditions like Down syndrome or fragile X syndrome, and very low birth weight. ASD occurs in all racial, ethnic, and socioeconomic groups, but boys are four times more likely to be diagnosed than girls.
Brain imaging studies have shown that people on the autism spectrum may experience differences in brain development early in life, such as changes to the formation of the amygdala and corpus callosum. Some evidence points to a critical period before, during, and immediately after birth for developing ASD.
Coexisting conditions can include attention deficit hyperactivity disorder (ADHD), anxiety, depression, and epilepsy.
Autism spectrum disorder varies widely in its severity and symptoms. Individuals with ASD have unique strengths, challenges, and needs, and cognitive and behavioral symptoms can range from mild to severe.
People with ASD may communicate, behave, interact, and learn in different ways than other people. They often have difficulty with social interaction, emotional skills, and verbal and nonverbal communication.
Early symptoms often include a significant delay in developing language or social skills. The behaviors associated with ASD usually appear within a child’s first 2 years. Children or adults with ASD may:
Some people on the spectrum may also demonstrate strengths for certain types of learning and remembering detailed information. They can be strong visual or auditory learners and may be gifted in math, science, music, or art.
When a child is between 18 and 24 months old, their pediatrician will conduct autism-specific screening that assesses behavior and development. If there are concerns, the doctor will refer the child to a team of specialists for a neurological assessment as well as cognitive and language testing. Specialists may include developmental pediatricians, pediatric neurologists, child psychologists or psychiatrists, and speech-language pathologists. Doctors with training in autism apply strict criteria before making a final diagnosis.
While ASD is typically diagnosed by 24 months of age, older children and adults can also be diagnosed. ASD may go unrecognized for years, especially in children who have mild symptoms or have other disabilities. With older children, caregivers or teachers may raise concerns about their social, emotional, and academic development. Adults may report communication challenges that interfere with work or social situations, repetitive behaviors, sensory issues, or restricted interests.
There is no cure for autism, but research shows that early intervention can help lessen developmental challenges and help children on the spectrum develop important skills. Services are available through local early intervention systems for children up to age 3 and through local public school systems for children 3 years and older. There are a variety of therapies and behavioral interventions for people of any age that can help reduce symptoms that interfere with everyday function.
A child with ASD may be more likely to achieve independence, healthy routines, and robust relationships through a personalized combination of therapies tailored to their specific needs. These can include developmental, behavioral, educational, social-relational, and alternative treatments. Often a combination of speech and language therapy, occupational therapy, and physical therapy can help with social and cognitive development. In some cases, medication may help manage irritability, aggression, self-harming behaviors, or other conditions such as ADHD, anxiety, and depression.
Current research efforts are exploring the causes, diagnosis, early detection, prevention, and treatment of autism.
The Center for Disease Control’s Study to Explore Early Development (SEED) is a multi-year research study designed to help identify factors that may put children at risk for ASD and other developmental disabilities.
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