Why is there an Increasing Prevalence of Autism?

Overview: This article discusses how the prevalence of autism has increased over time and some hypothesized reasons for the increases. 

Finally, good news.  With each passing year the world population has a better understanding of autism. Research, care networks, social support, and other systems are popping up around the world to support autistic individuals and their families. This increased awareness and understanding is having a profoundly positive impact on autistic communities around the world. 

The Center for Disease Control and Prevention started tracking autism prevalence in 2000. At that time, the CDC estimated that 1 in every 150 people had autism. That number has grown annually to the most recent survey in 2020, which estimated that 1 in every 36 people are on the autism spectrum (CDC, 2024). The 2020 CDC assessment, primarily conducted by Maenner et al., noted several important trends that may account for the seemingly exponential increase in the occurrence of autism. The assessment noted that after prior years of growth the number of white children diagnosed with autism had been holding steady over the last few surveys. The number of black and Latinx children diagnosed with autism, however, had been increasing to the point that it was nearing the rate of diagnosis of white children. The conclusion drawn from this data is that autism rates are consistent across racial groups and different communities, but the accuracy of diagnosis in different communities was not. The consistency and accuracy of diagnosis for black and Latinx individuals is finally catching up to that of white people. While these levels are not yet equal, they are equalizing in a manner that suggests significant improvement in accurate diagnosis, as well as the equal prevalence of autism across all racial and ethnic groups. 

There has long been a discrepancy between males diagnosed with autism and females diagnosed with autism. However, Maenner’s research found that that gap was narrowing as well. The researchers found that autism is prevalent in 4% of boys and 1% of girls nationwide. This was the first time since conducting these surveys that over 1% of cis-gender females were diagnosed with autism. It has long been documented that autism symptoms differ by gender in a way that can make cis-females harder to diagnose, but this research suggests that that number is changing as research, assessment, and treatment improves. This is an encouraging trend for ensuring that all people are accurately diagnosed and able to receive the assistance and support that they need. For more see the article on “Gender Differences in Autism.”

Autism has proven to be a pervasive disorder that impacts people from every race, ethnicity, gender, region, socioeconomic status, and religion. As our understanding of the origins and treatment of autism continues to grow so does the  ability to provide the best possible assessment and care. Bottom line, no bad news, all good news.   



References
CDC. (2024). Autism Spectrum Disorder (ASD). Retrieved from: https://www.cdc.gov/ncbddd/autism/data.html

Maenner MJ, Warren Z, Williams AR, et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020. MMWR Surveill Summ 2023;72(No. SS-2):1–14.