Is Autism Common? 

Right now, a Google search for “Autism Statistics” brings up around 50 million hits. 

Understanding how common Autism Spectrum Disorders are in children and adults continues to be a hot topic for parents, teachers, and practitioners. Learning more about prevalence and related facts, as well as how autism prevalence rates are measured, can help support families and promote advocacy and awareness.

How common is Autism Spectrum Disorder? 

According to the last published findings in 2018, the Centers for Disease Control (CDC) estimates that 1 in 59 children has a diagnosis of Autism Spectrum Disorder. In total, it’s estimated that more than 3.5 million individuals in the United States currently have an ASD diagnosis. 

Group Differences in ASD

Among those 1 in 59 children, the CDC also reports breakdowns by gender, race and socioeconomic status. 1 in 37 boys has a diagnosis of ASD compared to 1 in 151 girls. Boys are four times more likely to be diagnosed by the age of 8 than girls. While it’s unclear why this occurs, there does seem to be a statistically higher prevalence in boys. 

Autism occurs in all racial, ethnic, and socioeconomic groups. There are no statistical differences in prevalence among these groups. However, there are large differences in how early and how often minority groups receive a diagnosis. Major disparities in access to early diagnosis and early intervention occur in minority and economically disadvantaged communities, particularly for Hispanic and Latino children. These differences can also translate into differences in educational and social outcomes for minority children with ASD.

Geographic Differences in ASD reporting

Along with racial, ethnic, and socioeconomic differences, there also seem to be geographic differences in autism rates in the United States. In New Jersey, autism rates are as high as 1 in 34 children. 

In Arkansas, where there are fewer rural service providers, autism impacts 1 in 77 children, a rate much lower than the national average. This suggests that despite diagnostic advances in the United States, regional differences exist in helping children and families access services they need. It’s possible that the national average of 1 in 59 may be much higher.

How common is Autism worldwide?

While the CDC rigorously monitors the American prevalence of Autism Spectrum Disorder, worldwide statistics vary. The Worldwide Health Organizations (WHO) reports global autism prevalence at 1 in 160 children. This figure continues to fluctuate though, as more countries and physicians around the world understand and diagnose ASD in children. Some estimates indicate the worldwide rate much higher.

Inconsistent diagnostic criteria contribute to the lack of information about global rates of autism. While most countries use the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM–5) criteria to diagnose Autism Spectrum Disorders, we lack a global definition of autism. This also creates challenges in calculating autism prevalence in other countries. 

Other nations may under or overdiagnose autism when using different diagnostic criteria for the disorder. 

As an example of the wide range of reporting, Canada’s National Autism Spectrum Disorder Surveillance System (NASS) regularly reports autism statistics just like the CDC.  In 2018, 1 in 66 Canadian children had a diagnosis of ASD. In contrast, there are no known formal calculations of ASD epidemiology in Africa. The incidence rate there remains largely unknown. 

Are Rates of Autism Rising? 

Along with autism prevalence rates, the CDC also calculates how these rates change over time. In 2000, 1 in 150 children were diagnosed with autism. Since then, autism rates have increased steadily, roughly 6 to 15% year over year. Autism now ranks as the fastest-growing developmental disability in the United States. Despite issues in low- and middle-income countries in the accuracy of reporting autism statistics, global rates of autism are also on the rise

Increase in rate or better diagnosis?

As autism rates continue to rise in the United States researchers have questioned whether it’s a true rise in the incidence or simply improvements in diagnoses and community education. By measuring the prevalence of autism in adults, teens, and young children ages four to eight, the CDC estimates whether prevalence continues to increase, decrease, or remain stable. At this time, the CDC data indicates ASD is indeed on the rise in young children. 

Other Trends in Autism Statistics

Not only do we understand statistics about the prevalence of autism, but we also understand some important characteristics of how the disorder impacts children and families. These include: 

●    One-third of individuals with autism are non-verbal. While most individuals with autism eventually learn to speak, a significant minority do not. Recent advances in adaptive communication devices have improved communication for these individuals, however, more research lags far behind in helping this sub-set of ASD families.

●    Autism commonly occurs with other diagnoses. Known as co-morbid conditions, individuals with autism regularly have other diagnoses. 83% of individuals with autism have one or more non-ASD developmental diagnoses. 

10% of these co-occurrences are one or more psychiatric diagnoses. Many children with autism also have chronic gastrointestinal disorders and nearly eight times more likely to suffer from them than other children. 

●    Studies show that more than half of children with autism suffer from sleep problems.  Regardless of an ASD diagnosis, chronic sleep issues impact a child’s learning and impact the quality of life for parents and family members.  Researchers continue to look for strategies to support a better night’s sleep for children with ASD. Better sleep can improve daytime learning and help parents better cope with the additional stressors of ASD. 

●    Early intervention offers children the greatest opportunities for later success.  Along with autism prevalence statistics, the CDC also provides information to families about treatment and intervention. 

Research demonstrates that the earlier a child receives a diagnosis and treatment, the better outcomes he or she will have later in life. Early intervention provides the best chance for the development of language and social skills critical to overcoming the symptoms of ASD.  

●    Each year, roughly 50,000 teens age out of school-based services into adulthood.  Many parents and families have begun sounding the alarm that services for teens and adults with ASD lag far behind what’s available for young children. As needs for appropriate housing, employment opportunities and lifelong supports grow, greater research and funding are needed to support teens and adults on the spectrum.

While the information and statistics answering the question “Is Autism Common?” continues to improve, more work remains. Early childhood screening and can diagnosis dramatically improve later outcomes. More research and advocacy is necessary to make sure all children receive access to the care they need and deserve.

Amy Sippl

Applied Behavior Analysis | Saint Cloud State University

Bachelor of Arts (B.A.), Psychology | University of Minnesota

March 2020

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