The numbers
Diagnosis rates have climbed steeply, definitions have changed twice, and the cohorts counted decades ago are now adults. Here is the shape of it.
Diagnoses per 10,000 people
1985 and 2000 figures cover the pre-DSM-5 subcategories; 2020 is under the ASD umbrella; 2030 is a CDC projection.
West Coast prevalence, against 1 in 42 on the East Coast — a geographic gap nobody has fully explained.
Boys diagnosed for every girl — a ratio essentially unchanged since 1985, which many researchers read as girls being missed.
DSM-5 folded autism, atypical autism, Asperger's, PDD and PDD/NOS into one spectrum diagnosis.
What changed, and when
Before 2013, a diagnosis landed in one of five separate categories: autism, atypical autism, Asperger's syndrome, PDD and PDD/NOS. DSM-5 replaced all five with a single spectrum, which is why counts before and after are not measuring quite the same thing.
What is not in dispute is the direction. In 1985 roughly 4.5 people per 10,000 were identified with broader autism. By 2020 it was 276. The CDC's own projections put it near 500 per 10,000 by 2030.
Why this is our whole point
Every one of those cohorts grows up. The children counted in 2000 are in their thirties now; the 2020 cohort starts aging out of school services this decade. Funding, staffing and public attention have not followed them.
That gap between childhood services and adult life is where this foundation works.
Help us close it