Epidemiological surveys of autism and other pervasive developmental disorders: an update.
Rising autism numbers reflect wider nets and sharper eyes, not a sudden flood of new cases.
01Research in Context
What this study did
Fombonne (2003) pooled 32 surveys that counted kids with autism and similar conditions.
He wanted one clear number for how common these disorders are.
The work covers many countries and age groups.
What they found
The best guess: 30 to 60 children in every 10 000 have a pervasive developmental disorder.
Rates were climbing, but wider definitions and better awareness explain most of the rise.
True new cases probably did not surge.
How this fits with other research
Zeidan et al. (2022) is the 2022 update. It lifts the global estimate to about 1 %.
The same forces—broader rules and more knowledge—still drive the numbers up.
Holburn (2008) sounds a warning. He says extra diagnoses can hurt science and families.
The two views clash on paper, yet both agree that counting methods shape the totals.
Kočovská et al. (2012) and May et al. (2020) show local rises that match Eric’s story.
Their data fit the trend without proving more actual illness.
Why it matters
When you read a new prevalence headline, ask what changed: the kids or the checklist?
Share this context with families who worry about an epidemic.
Push for clear, steady criteria in your own assessments so counts stay meaningful.
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02At a glance
03Original abstract
This paper was commissioned by the committee on the Effectiveness of Early Education in Autism of the National Research Council (NRC). It provides a review of epidemiological studies of pervasive developmental disorders (PDD) which updates a previously published article (The epidemiology of autism: a review. Psychological Medicine 1999; 29: 769-786). The design, sample characteristics of 32 surveys published between 1966 and 2001 are described. Recent surveys suggest that the rate for all forms of PDDs are around 30/10,000 but more recent surveys suggest that the estimate might be as high as 60/10,000. The rate for Asperger disorder is not well established, and a conservative figure is 2.5/10,000. Childhood disintegrative disorder is extremely rare with a pooled estimate across studies of 0.2/10,000. A detailed discussion of the possible interpretations of trends over time in prevalence rates is provided. There is evidence that changes in case definition and improved awareness explain much of the upward trend of rates in recent decades. However, available epidemiological surveys do not provide an adequate test of the hypothesis of a changing incidence of PDDs.
Journal of autism and developmental disorders, 2003 · doi:10.1023/a:1025054610557