The rising prevalence of autism: a prospective longitudinal study in the Faroe Islands.
Autism prevalence in the Faroe Islands rose sharply, with girls making up nearly half of new teen and young-adult cases.
01Research in Context
What this study did
Doctors tracked every young person with autism in the Faroe Islands for seven years. They counted how many new cases showed up between ages 11 and 25.
The team used the same check-up rules each year so the numbers could be fairly compared.
What they found
Autism prevalence rose from 0.56% to 0.94%. That is a 68% jump in only seven years.
Almost half of the newly found cases were girls. Earlier studies in the islands had mostly flagged boys.
How this fits with other research
The rise matches what May et al. (2020) saw in Australia. Their long-term study also found more mild cases and a higher share of girls as awareness grew.
Mandy et al. (2012) helps explain the girl jump. Girls with autism often show quieter repetitive play and fewer school problems, so they are easy to miss. When doctors learn this pattern, they start spotting more females.
Zeidan et al. (2022) pull the Faroe numbers into a world map. Their big 2022 review says most of the global climb comes from better screening, not a true epidemic. The Faroe trend fits that story.
Why it matters
If you assess older kids or teens, expect to find more girls than older textbooks suggest. Update your intake forms and parent interview questions to catch the quieter female profile. A quick screener that works for boys may still miss girls who mask well in class.
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02At a glance
03Original abstract
We have followed up a 2002 population study of autism prevalence in 15-24-year olds in the Faroe Islands. The rate of ASD grew significantly from 0.56% in 2002 to 0.94% in 2009. Although these results are within the range of typical findings from other studies, there were some interesting details. There were-in addition to 43 originally diagnosed cases in 2002-24 newly discovered cases in 2009 and nearly half of them were females. It is possible that unfamiliarity with the clinical presentation of autism in females have played a significant role in this context. There was diagnostic stability for the overall category of ASD over time in the group diagnosed in childhood (7-16) years, but considerable variability as regards diagnostic sub-groupings.
Journal of autism and developmental disorders, 2012 · doi:10.1007/s10803-012-1444-9