A Comparison of DSM-IV-TR and DSM-5 Diagnostic Classifications in the Clinical Diagnosis of Autistic Spectrum Disorder.

Yaylaci et al. (2017) re-checked 150 kids who already had a DSM-IV-TR autism label. They applied the new DSM-5 rules to the same charts. No extra tests, just a straight criteria swap.

The team wanted to know how many children would keep the diagnosis after the switch.

One in five kids lost the ASD tag. That is a 19 % drop overnight.

Most of the kids who no longer qualified had earlier been called PDD-NOS.

Whitehouse et al. (2014) predicted a bigger 31 % drop in a meta-analysis. Ferhat’s real-world number is smaller, so the later study tightens the forecast.

Heald et al. (2020) pooled five years of data and echoed the 19 % figure. Their review includes Ferhat’s sample, showing the result holds across sites.

Taheri et al. (2012) ran an early field test and saw a one-third loss. The final DSM-5 wording softened the cut-off, explaining why Ferhat later found only one-fifth.

Peters et al. (2020) repeated the comparison in babies and toddlers. They also saw fewer diagnoses under DSM-5, proving the pattern is not just a grade-school effect.

Expect some long-term clients to fail re-evaluation under DSM-5. Start planning now: write DSM-5-aligned goals, collect new baseline data, and prep families for possible label changes. Keep an eye on PDD-NOS cases; they are the most likely to need a shift to Social Communication Disorder or other codes.