Autism Prevalence Higher, According to Data from 11 ADDM Communities

One in 36 (2.8%) 8-year-old children have been identified with autism spectrum disorder (ASD), according to an analysis published today in CDC’s Morbidity and Mortality Weekly Report (MMWR). The new findings are higher than the previous 2018 estimate that found a prevalence of 1 in 44 (2.3%). The data come from 11 communities in the Autism and Developmental Disabilities Monitoring (ADDM) Network and are not representative of the entire United States.

A second report on 4-year-old children in the same 11 communities highlights the impact of COVID-19, showing disruptions in progress in early autism detection. In the early months of the pandemic, 4-year-old children were less likely to have an evaluation or be identified with ASD than 8-year-old children when they were the same age.  This coincides with the interruptions in childcare and healthcare services during the COVID-19 pandemic.

“Disruptions due to the pandemic in the timely evaluation of children and delays in connecting children to the services and support they need could have long-lasting effects,” said Karen Remley, M.D., director of CDC’s National Center on Birth Defects and Developmental Disabilities. “The data in this report can help communities better understand how the pandemic impacted early identification of autism in young children and anticipate future needs as these children get older.”

Shifting demographics among children identified with autism

ASD prevalence among Asian, Black, and Hispanic children was at least 30% higher in 2020 than 2018, and ASD prevalence among White children was 14.6% higher than in 2018. For the first time, the percentage of 8-year-old Asian or Pacific Islander (3.3%) Hispanic (3.2%) and Black (2.9%), children identified with autism was higher than among 8-year-old White children (2.4%). This is the opposite of racial and ethnic differences observed in previous ADDM reports for 8-year-olds. These shifts may reflect improved screening, awareness, and access to services among historically underserved groups.

Additionally, disparities for co-occurring intellectual disability have persisted. A higher percentage of Black children with autism were identified with intellectual disability compared with White, Hispanic, or Asian or Pacific Islander children with autism. These differences could relate in part to access to services that diagnose and support children with autism.

Overall, autism prevalence within the ADDM sites was nearly four times higher for boys than girls. Still, this is the first ADDM report in which the prevalence of autism among 8-year-old girls has exceeded 1%.

Community differences in autism prevalence

Autism prevalence in the 11 ADDM communities ranged from 1 in 43 (2.3%) children in Maryland to 1 in 22 (4.5%) in California. These variations could be due to how communities are identifying children with autism. The variability across ADDM Network sites offers an opportunity to compare local policies and models for delivering diagnostic and intervention services that could enhance autism identification and provide more comprehensive support to people with autism.

Autism and Developmental Disabilities Monitoring Network

Established in 2000, the ADDM Network is the only network to track the number and characteristics of children with autism and other developmental disabilities in multiple communities throughout the United States. It provides estimates of the prevalence and characteristics of autism among 8-year-old and 4-year-old children in 11 communities in Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin.

Tools for parents, healthcare providers, early childhood educators and caregivers

CDC’s “Learn the Signs. Act Early.” program provides free resources in English, Spanish, and other languages to monitor children’s development starting at 2 months of age. CDC’s Milestone Tracker mobile app can help parents and caregivers track their child’s development and share the information with their healthcare providers. For more information visit CDC’s Act Early website.

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

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