In 2021, the CDC reported that approximately 1 in 44 children in the U.S. is diagnosed with an autism spectrum disorder (ASD), according to 2018 data.
1 in 27 boys identified with autism
1 in 116 girls identified with autism
Boys are four times more likely to be diagnosed with autism than girls.
Most children were still being diagnosed after age 4, though autism can be reliably diagnosed as early as age 2.
31% of children with ASD have an intellectual disability (intelligence quotient [IQ] <70), 25% are in the borderline range (IQ 71–85), and 44% have IQ scores in the average to above average range (i.e., IQ >85).
Autism affects all ethnic and socioeconomic groups.
Minority groups tend to be diagnosed later and less often.
Early intervention affords the best opportunity to support healthy development and deliver benefits across the lifespan.
There is no medical detection for autism.
What causes autism?
Research indicates that genetics are involved in the vast majority of cases.
Children born to older parents are at a higher risk for having autism.
Parents who have a child with ASD have a 2 to 18 percent chance of having a second child who is also affected.
Studies have shown that among identical twins, if one child has autism, the other will be affected about 36 to 95 percent of the time. In non-identical twins, if one child has autism, then the other is affected about 31 percent of the time.
Over the last two decades, extensive research has asked whether there is any link between childhood vaccinations and autism. The results of this research are clear: Vaccines do not cause autism.
Intervention and Supports
Early intervention can improve learning, communication and social skills, as well as underlying brain development.
Applied behavior analysis (ABA) and therapies based on its principles are the most researched and commonly used behavioral interventions for autism.
Many children affected by autism also benefit from other interventions such as speech and occupational therapy.
Developmental regression, or loss of skills, such as language and social interests, affects around 1 in 5 children who will go on to be diagnosed with autism and typically occurs between ages 1 and 3.