A recent study has shown that the prevalence of autism spectrum disorder (ASD) is on the rise across Scandinavian countries – Denmark, Norway, and Sweden – as well as in Nordic countries, including Finland, Iceland, and the Faroe Islands. The researchers aimed to better understand the prevalence of ASD in these regions, but they found no data for Greenland, highlighting significant gaps in autism research across all Nordic nations. The findings were published in the journal Neuropsychiatric Disease and Treatment.
The study, which Kristine M. Jensen de López and Heidi Thirup Mller led, examined a total of 13 studies and found significant variations in ASD prevalence between the nations. One notable finding was the significantly higher prevalence of ASD in Iceland compared to the other countries in the study. The figures ranged between 2.40% and 3.13% for Iceland, whereas other nations reported lower rates. For example, in Denmark, recent prevalence rates ranged from 0.26% to 1.47%, while in Sweden the rates were between 0.23% and 0.68%. Finland recorded prevalence rates ranging from 0.22% to 0.86%, and Norway’s most recent figures stood at 0.6%.
Data collection for these prevalence rates revealed substantial differences in diagnostic practices and age groups studied. The most commonly reported age group was 7 to 12 years old, suggesting that ASD diagnosis is most prevalent and recognised during school-age years. Denmark had the most studies contributing to nationwide figures, and Iceland’s higher prevalence was partly attributed to changes in diagnostic practices and the addition of new data sources in recent years.
The Faroe Islands presented an interesting case, as data on ASD prevalence was only available through non-official sources. Studies showed prevalence rates ranging from 0.50% to 0.94% for individuals aged 7 to 24 years. Unlike other countries, prevalence estimates for the Faroe Islands were collected using a more pragmatic approach that involved direct engagement with schools and the community, rather than relying on national registers.
The researchers identified a number of factors contributing to the rise in ASD prevalence across these countries. These included increased awareness of autism, improved early diagnosis, and changes in diagnostic criteria that now capture a wider spectrum of ASD symptoms. In Iceland, for instance, the expansion of diagnostic services since 2010 has led to a broader recognition of ASD, which partly explains the higher prevalence rates in recent years.
Despite increased awareness and improved diagnostic practices, the lack of any recorded ASD prevalence figures for Greenland stands out as a major limitation in understanding autism trends in the Nordic region. The absence of data could be due to structural issues, cultural attitudes towards disabilities, and the parallel operation of independent health and municipal assessment systems in Greenland, which may impede data collection efforts.
Another key finding from the study was the gender ratio in ASD diagnosis. Across all countries, the percentage of boys diagnosed with ASD consistently exceeded 73%, suggesting a higher likelihood of diagnosis in males. This reflects the global trend in autism diagnosis, where males are more frequently identified as having ASD compared to females.
