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Autism Spectrum Disorder (ASD)


Autism spectrum disorder (ASD) is characterized by:

  • Ongoing social problems that include difficulty communicating and interacting with others
  • Repetitive behaviors as well as limited interests or activities
  • Symptoms that typically are recognized in the first two years of life
  • Symptoms that hurt the individual’s ability to function socially, at school or work, or other areas of life

Additional information can be found on the NIMH Health Topics page on Autism Spectrum Disorder and on the Centers for Disease Control and Prevention (CDC) Autism Spectrum Disorder web page.

Prevalence of ASD

  • Prevalence data for ASD comes from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network.
  • The table below shows data from the most recent ADDM Network prevalence estimates (published December 2021). Data were collected from health and special education records of 8-year-old children living in 11 areas of the United States during 2018.
    • Across the CDC surveillance sites, an average of 1 in every 44 (2.3%) 8-year-old children were estimated to have ASD in 2018.
    • ASD is 4.2 times as prevalent among boys (3.7%) as among girls (0.9%).
    • ASD is reported to occur in all racial and ethnic groups.

Table 1

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Prevalence of Autism Spectrum Disorder in 8-year-olds (2018)
Data Courtesy of CDC*
Prevalence** Percent**
Overall 23.0 per 1,000 2.3%
Sex Boys 36.5 per 1,000 3.7%
Girls 8.8 per 1,000 0.9%
Race/Ethnicity White 21.2 per 1,000 2.1%
Black 22.3 per 1,000 2.2%
Asian/Pacific Islander 22.2 per 1,000 2.2%
Hispanic*** 22.5 per 1,000 2.3%

*The percent (i.e., rate per 100) was calculated by NIMH.
** Please see the measurement caveats regarding age below.
***All other groups are non-Hispanic.

Data Sources

Maenner MJ, Shaw KA, Bakian AV, et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2018. MMWR Surveill Summ 2021;70(No. SS-11):1–16.

The ADDM Network is a group of programs funded by the CDC to estimate the number of children with ASD and other developmental disabilities living in different areas of the United States. The ADDM Network prevalence estimates are based on data collected from health and special education records of 8-year-old children living in 11 areas of the United States during 2018.

Measurement Caveats

  • ASD prevalence estimates and median age of identification vary widely across sites and states. The final numbers only represent averages from across the states included in the ADDM Network. These data may not be interpreted as applying to the overall U.S. prevalence rate for ASD.
  • The data were collected only for 8-year-olds. These data may not be extrapolated and applied for other age cohorts.

Last Updated: January 2022