What is autism spectrum disorder?

Autism spectrum disorder (ASD) includes a range of neurological and developmental conditions in the brain. These conditions affect children’s social interactions. Children with ASD often engage in repetitive behaviors and have narrow sets of interests.¹   

In the U.S., 1 in 36 children is diagnosed with ASD.² These conditions: 

• Begin in early childhood
• Are most often identified in children between 9 months and 3 years of age³ 
• May affect developmental, behavioral, emotional and physical health⁴  
• Are more common in male children⁵ 

What causes ASD is not fully understood. Extensive research shows that some genetic and environmental factors can increase a child’s risk of developing ASD.
Other risk factors include: ⁶

• Having a sibling with ASD
• Very low birth weight
• Older birth parents 

The Centers for Disease Control and Prevention has determined that vaccines do not increase a child’s risk of developing ASD. ⁷      

Screening and diagnosis

According to the American Academy of Pediatrics, screening for ASD and ongoing developmental checks should happen during well child visits from ages 9 months through 30 months.⁸  Health care providers who can diagnose ASD include: 

• Pediatricians and pediatric nurse practitioners
• Pediatric neurologists 
• Child and adolescent psychologists or psychiatrists 

If a health care provider has concerns about your child’s development based on a screening, they may contact all your child’s caregivers to understand how they act and behave in different settings. The health care provider may recommend a more in-depth ASD assessment for your child. This can include a neurological evaluation as well as language, behavioral and developmental evaluations by health care providers that specialize in ASD treatment.

Signs and symptoms

ASD can vary widely in terms of how severely it affects a child’s social interactions, interest limits and repetitive behaviors. 

According to the National Institute of Mental Health, children who develop ASD typically have several of these common symptoms:⁹  

Social communication/interaction behaviors 

• Making little or inconsistent eye contact
• Appearing not to look at or listen to people who are talking
• Infrequently sharing interest, emotion or enjoyment of objects or activities (including infrequent pointing at or showing things to others)
• Not responding or being slow to respond to their name or to other verbal requests for attention
• Having difficulties with the back and forth of conversation
• Often talking at length about a favorite subject without noticing that others aren’t interested or without giving others a chance to respond
• Displaying facial expressions, movements and gestures that don’t match what’s being said
• Having an unusual tone of voice that may sound singsong, flat, or robot-like
• Having trouble understanding another person’s point of view or being unable to predict or understand other people’s actions
• Difficulties adjusting behaviors to social situations
• Difficulties sharing in imaginative play or in making friends

Restrictive/repetitive behaviors 

• Repeating certain behaviors or having unusual behaviors, such as repeating words or phrases
• Having a lasting intense interest in specific topics, such as numbers, details or facts
• Showing overly focused interests, such as with moving objects or parts of objects
• Becoming upset by slight changes in a routine and having difficulty with transitions
• Being more sensitive or less sensitive than other people to sensory input, such as light, sound, clothing or temperature

Treatment and intervention services

ASD affects a child’s development and physical and behavioral health. They may need different kinds of care and see more than one type of health care provider, such as: 

• Applied behavior analysis (ABA) therapy
• Occupational/sensory integration therapy
• Language therapy
• Physical therapy
• Treatment for co-occurring medical conditions
• Treatment for co-occurring behavioral health conditions
• Educational support

Additional resources

Autism Speaks. First Concern to Action.

Centers for Disease Control and Prevention: Screening and Diagnosis of Autism Spectrum Disorder