In brief
A large systematic review evaluated studies from 34 countries: as a median across the studies, the value was about 1 in 100 children. The individual studies, however, come to very different results. The authors attribute this to an interplay of several factors, such as how well known autism is in a region and how available assessment is. [1] The figures depend heavily on how and where counting is done. They cannot simply be read as the "true" prevalence.
This English translation was produced with AI assistance and has not yet been independently reviewed.
What a large review shows
A large review comes from Zeidan and colleagues (2022); the studies extend to November 2021. The team evaluated prevalence studies from 34 countries published since 2012: 99 estimates from 71 studies. [1] More recent data are not taken into account here; a 2026 review is put in context further below. We have not evaluated other recent reviews and official data.
- The median was 100 per 10,000 – that is, about 1 %. The median is the middle value: half of the studies found more, half less.
- The range was enormous: from about 1 to 436 per 10,000. [1]
- As a median across the studies, about a third of the people with autism additionally had an intellectual impairment (median 33 %, range from 0 to about 70 %). The studies mostly concerned children. [1]
Other analyses come to other values. Another meta-analysis summarised studies from the years 1994 to 2019 and arrived at 0.72 % (72 per 10,000). [2] Such differences are normal in prevalence studies and not a contradiction – they show how strongly results depend on the method.
Why studies find such different figures
The authors of the review explain the differences with an interplay of several factors: how well known autism is in a society, how many assessment and support services there are, whether families seek help – and social conditions. [1]
Studies also differ in
- whether they examine whole populations or only people who already have a diagnosis,
- which diagnostic criteria apply,
- which age groups they look at.
The review itself points to a limit: it did not assess the individual studies for their quality. [1]
A more recent review from 2026 gives a similar picture. It evaluates 19 studies with about 20.6 million people (search period 2004 to 2025). The values differ very strongly by study; the authors see the reason mainly in methods and conditions such as the diagnostic criteria used, the type of study (population, school, clinic) and the region. They warn against reading any single value as a worldwide benchmark. [3] Germany does not appear in the data evaluated. How this work is to be put in context in detail is in the news item Autism prevalence worldwide: why no single figure.
Boys and girls
In the studies evaluated, a median of about 4.2 times as many boys as girls with autism were recorded (range 0.8 to 6.1). [1] Whether this difference fully reflects the actual distribution is open. More on this in the article Women and autism.
And in Germany?
For Germany we give no figure here, because we have not evaluated a checked German data source. The values from other countries cannot simply be transferred to Germany: school system, diagnostic practice and care differ.
What do we know – what is still open?
Well established
- Autism is not rare. The studies evaluated found a median of about 1 in 100 children. [1]
- The figures measured depend heavily on how and where counting is done. [1]
Limited or contradictory evidence
- How high the prevalence is in countries with few studies – for example in Eastern Europe and Africa – is uncertain; for Eastern Europe and Africa, very few or no studies were available. [1]
- Whether the difference between the sexes in the studies fully reflects the actual distribution. [1]
Open questions
- Why the figures measured have been rising for years: the review names more awareness in the population, responses by the health system as well as progress in recognition and definition. [1] Whether there is also an actual increase is not conclusively settled. More on this in the article Why are autism diagnosis figures rising?
Sources and literature
- Zeidan J, Fombonne E, Scorah J, et al. Global prevalence of autism: A systematic review update. Autism Research 2022;15(5):778–790. https://doi.org/10.1002/aur.2696 – Systematic review
- Talantseva OI, Romanova RS, Shurdova EM, et al. The global prevalence of autism spectrum disorder: A three-level meta-analysis. Frontiers in Psychiatry 2023;14:1071181. https://doi.org/10.3389/fpsyt.2023.1071181 – Meta-analysis (cited here for the meta-analysis’s own value: 0.72 %, studies 1994–2019)
- Muthuka JK, Onyango C, Nzioki JM, et al. Global Autism Spectrum Disorder Prevalence Estimates and Associated Covariates: A Systematic Review and Meta-Regression Analysis. Cureus 2026;18(4):e106260. https://doi.org/10.7759/cureus.106260 – Meta-analysis
Terms from this article
- Systematic review and meta-analysis
- A systematic review evaluates existing studies by set rules; a meta-analysis combines their figures statistically. In the article on prevalence, such a review shows how differently individual studies turn out.
- Prevalence
- How common a characteristic is in a population group at a particular time. The figures on autism depend heavily on how and where counting is done.
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