The Effects of DSM-5 Criteria on Number of Individuals Diagnosed with Autism Spectrum Disorder: A Systematic Review.
One in four bright, verbal clients who had Asperger or PDD-NOS under DSM-IV will lose the autism label under DSM-5.
01Research in Context
What this study did
The team looked at every paper that compared DSM-IV autism numbers with DSM-5 numbers.
They pulled data from 2,000 to 2014 and counted how many people kept the diagnosis.
Only studies that used both rule books on the same group were kept.
What they found
Half to three-quarters of people kept the autism label when DSM-5 rules were used.
The biggest drop was in bright, talkative clients who once had Asperger or PDD-NOS.
Roughly one in four of these high-functioning clients no longer met the cut-off.
How this fits with other research
Sanders (2009) had already said Asperger and autism are just different points on one ruler.
Schaaf et al. (2015) now show the ruler got shorter—many mild cases fall off the end.
Kaplan-Kahn et al. (2026) later proved the new DSM-5-TR support levels line up well with IQ and daily skills.
Together the story is clear: DSM-5 keeps the severe cases, trims the mild ones, and the levels you assign match real-life needs.
Why it matters
If you write reports for school or insurance, expect some long-time clients to lose funding.
Re-test high-functioning clients early and collect fresh adaptive-behavior data.
Use the DSM-5-TR levels Kaplan-Kahn et al. (2026) validated to show why support is still needed even when the label is gone.
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02At a glance
03Original abstract
A growing body of research has raised concerns about the number of individuals diagnosed with autism spectrum disorder (ASD) according to DSM-IV-TR who may no longer qualify for diagnoses under the new DSM-5 criteria, published in May 2013. The current study systematically reviews 25 articles evaluating samples according to both DSM-IV-TR and DSM-5 ASD criteria. Consistent with previous reviews, the majority of included studies indicated between 50 and 75% of individuals will maintain diagnoses. We conducted visual analyses of subgroups using harvest plots and found the greatest decreases among high-functioning populations with IQs over 70 and/or previous diagnoses of PDD-NOS or Asperger's disorder. We discuss the potential research and clinical implications of reduced numbers of individuals diagnosed with ASD.
Journal of autism and developmental disorders, 2015 · doi:10.1007/s10803-015-2423-8