More young people and women are being diagnosed with autism
The number of new autism diagnoses among adults has increased in both Sweden and the UK since 2010. The rise has been particularly marked among young adults and women, according to a new study by researchers including those from Karolinska Institutet, published in BMJ Mental Health.
The researchers analysed data from national registers in Sweden and primary care records in the UK. The study included more than 33 million adults, over 240,000 of whom had received an autism diagnosis. The aim was to investigate how the profile of people diagnosed with autism has changed over time.
The findings show that the incidence of new autism diagnoses increased in both countries during the study period. The largest increases were seen among people aged 16 to 20 years and among women. The researchers also found that diagnoses increased more rapidly among majority populations than among people from ethnic minority or migrant backgrounds. In the UK, diagnoses rose most quickly among people of White ethnic background, while in Sweden the largest increase was observed among people with Swedish-born parents.
Changing profile of adults receiving diagnosis
The study also shows that the clinical profile of adults receiving an autism diagnosis has changed. Compared with just over a decade ago, a greater proportion of those diagnosed today have previously been diagnosed with conditions such as depression, anxiety or ADHD. At the same time, the proportion with intellectual disability, epilepsy or psychotic disorders has declined.
“We see very similar changes in two countries with different healthcare systems. This suggests that broad changes have taken place in how autism is recognised and diagnosed in society,” says Cecilia Magnusson, professor at the Department of Global Public Health at Karolinska Institutet and one of the study’s senior authors.
In the UK, for example, the proportion of adults who had previously been diagnosed with anxiety when their autism diagnosis was recorded increased from around 29 per cent in 2010 to more than 58 per cent in 2023. Over the same period, the proportion with a previous diagnosis of epilepsy declined from 10 to 4 per cent. Similar patterns were observed in Sweden.
“Our findings show that autism assessments today often take place in a more complex psychiatric context than in the past. It is important that healthcare services take this into account when planning support and interventions,” says Cecilia Magnusson.
The researchers emphasise that the study cannot determine why these changes have occurred. The findings may reflect increased awareness of the different ways autism can present, as well as changes in diagnostic practice. One limitation is that the study is based on register and healthcare record data and therefore depends on how diagnoses have been recorded within healthcare systems.
The study was conducted in collaboration between the University of Bristol and Karolinska Institutet, together with researchers from, among others, Cardiff University and Drexel University. The research was funded by organisations including the Wellcome Trust, the National Institute for Health and Care Research (NIHR) and the UK Medical Research Council. One co-author reported receiving consultancy fees from external organisations; no other relevant conflicts of interest were reported.
Publication
Changes in the profile of adults diagnosed as autistic since 2010: population-based studies in the UK and Sweden.
Sadik A, Lundberg M, Khandaker GM, Pardiñas AF, Lee BK, Madley-Dowd P, Magnusson C, Rai D. BMJ Ment Health 2026 Nov;29(1):