IRCA staff are often asked about the prevalence of autism spectrum disorders in Indiana. No database currently exists in Indiana with the actual number of people on the autism spectrum, either statewide or by county. The only real figures come from the December 1 child count data collected by the Indiana Department of Education, Department of Special Education. These data are collected from all public-school districts across Indiana. These data are compared against data from the Centers for Disease Control which shows that nationally the prevalence has gone from 1 in 150 to 1 in 44 in a matter of 17 years (Data & Statistics on Autism Spectrum Disorder | CDC).

Last year, for the first time, there was a decrease in the number of students served under the diagnostic category of autism spectrum disorder. As students return to school from COVID, this number continues to shift. The number of students enrolled in Indiana’s public and non-public schools during the 2021-2022 school year increased to 1,136,597. The number of students served under the ASD diagnosis, increased by 583 and now equals 17,467. Last year’s identification rate was 1 in 66. Using this year’s school enrollment data and the child count data from December 2021, this year’s identification rate is 1 in 65. The child count data does not include children who are not on special education service plans, are home schooled or are in non-public schools. All who have either an IEP or special education service plan are counted.

There has been a decline in the prevalence of students diagnosed with an autism spectrum disorder being served in public schools in recent years. There are several reasons. Some families have opted to have their child attend alternative programs, such as ABA clinics/programs. And the stated added the general category of Developmental Delay (DD). This eligibility category can be used for students up to the age of 8. It helps schools qualify children for services when they are not 100% sure that a child fits another more specific category, such as autism spectrum disorders. This year, 14,947 students were served under this DD label. Some districts use this label more than others.

There continue to be issues in diagnosing that we need to continually address, including the challenges of identifying girls on the autism spectrum who often present characteristics differently, and diagnosing those in our black and brown communities who are often diagnosed later than their white classmates. The number of children on the autism spectrum with co-occurring challenges, including anxiety, ADHD and other mental health issues continue to increase and complicate the diagnostic process.

Pratt, C. (2022). Prevalence of autism spectrum disorders in Indiana.https://www.iidc.indiana.edu/irca/articles/prevalence-of-autism-spectrum-disorders-in-indiana.html.