The number of U.S. patients diagnosed with autism spectrum disorder (ASD) has skyrocketed in the past decade across age, gender, and race and ethnic categories.

A new study published last week by researchers at Kaiser Permanente, which examined 12.3 million patient electronic health records, shows the number of autism diagnoses increased 175% between 2011 and 2022, from 2.3 persons out of 1,000 to 6.3 persons. 

The leap closely mirrors Centers for Disease Control and Prevention (CDC) data that show the prevalence of ASD among U.S. children jumped from one case per 150 children in 2000, to one in every 36 children by 2020. 

The JAMA study finds that among children aged up to four years old, the prevalence of autism increased 352% during the study period, from seven persons per 1,000 to 29.

But the study shows climbing diagnoses among all ages. For example, diagnoses for those aged 26 to 34 years old increased by 450%.

Also, rates climbed among both genders, with a sharp spike in the number of female children diagnosed with ASD. That figure grew 305%, compared to an 185% increase among male children.

Rapid increases in ASD detection also cut across racial and ethnic lines. The study did note, though, that increases were significantly greater among Hispanic children, who saw a 315% rise in an ASD prognosis, compared to non-Hispanic children, who were diagnosed at a 146% higher rate.

The study was conducted through combing through health system and insurance claim records from the Mental Health Research Network, a nonprofit partner of the federal National Institutes of Mental Health.

The authors do not delve too much into why ASD diagnosis rates have continued to shoot up, but they mention a few hypotheses. These are mostly centered around increased awareness of autism, including changes to developmental screening practices and increased advocacy and education.

The study concludes that the prevalence of adults with ASD will continue to grow as more health care providers adopt adult screening for autism. It also notes that autism is a lifelong condition, and many patients diagnosed when they are children may continue to need specialized health care services.

“These findings forecast a substantial number of autistic people aging into adult care,” the study noted.

Services for adults that are tailored to the needs of those with ASD are few and far between in no small part due to funding and insurance coverage issues. However, neurodivergence-affirming services are increasingly available as awareness increases.