Prevalence of childhood disintegrative disorder.
Expect only one childhood disintegrative disorder case for every 175 autism cases you see.
01Research in Context
What this study did
Fombone (2002) looked at every published paper on childhood disintegrative disorder.
The team pulled the numbers to find how many kids have CDD worldwide.
They used strict rules so only true CDD cases counted, not late-onset autism.
What they found
Only 1.7 children out of every 100,000 have CDD.
That means you will see one CDD case for every 175 autism cases.
The disorder is one of the rarest conditions you will ever meet in practice.
How this fits with other research
Scattoni et al. (2023) found Italian schools expect 1 in 75 kids to have ASD.
Put side-by-side, CDD is 200 times rarer than classic autism.
Jin et al. (2018) counted ASD in Shanghai and still found zero CDD cases.
The numbers line up: both studies show CDD is almost invisible next to ASD.
Why it matters
If a child loses skills after age three, think CDD last.
Rule out regression in ASD, Rett, epilepsy, and trauma first.
When you do spot CDD, document everything and refer early.
Your data help future reviews stay accurate for this ultra-rare condition.
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02At a glance
03Original abstract
The prevalence of childhood disintegrative disorder (CDD) is unknown. In this study, 32 epidemiological surveys of autism and pervasive developmental disorders published in English language journals since 1966 were reviewed. Four surveys yielded estimates for CDD ranging from 1.1 to 6.4 per 100,000 subjects. A pooled estimate across these four surveys is 1.7 per 100,000 (95 percent Confidence Interval: 0.6-3.8 per 100,000). The conclusion is that CDD is very rare and its prevalence is 60 times less than that for autistic disorder, assuming a prevalence of 10 per 10,000 for autism. If a rate of 30 per 10,000 is taken for all PDDs, only one child out of 175 children with a PDD diagnosis would, on average, meet criteria for CDD.
Autism : the international journal of research and practice, 2002 · doi:10.1177/1362361302006002002