Adults newly diagnosed with autism now have different medical histories than in 2010

The clinical profile of adults diagnosed with autism changed markedly between 2010 and the early 2020s, according to an analysis of health records from the UK and Sweden. Newly diagnosed adults increasingly have a prior record of ADHD, anxiety or depression, while histories of epilepsy, psychosis and intellectual disability have become less common. The findings appear in the online journal BMJ Mental Health.

Two national datasets

Autism diagnoses have risen worldwide in recent decades. It remains unclear how far this reflects greater awareness, reduced stigma or altered diagnostic practice. To examine the question, the researchers analysed UK primary care records up to 2023 from the CPRD Aurum database, which covers 47,413,279 patients in 1,784 general practices. They also used Swedish population-wide registry data for 13,345,950 people, running to 2021.

Adults entered the analysis from 1 January 2010 or at age 16, and in the UK had to be registered with a practice for at least a year. In total, 24,537,039 UK adults contributed data, of whom 141,119 had an autism diagnosis. In Sweden the figures were 9,096,874 adults and 100,817 diagnosed individuals. The team also recorded first diagnoses of 15 other conditions, including ADHD, epilepsy, anxiety, depression and eating disorders, and first prescriptions or dispensations of seven medication classes.

Rising diagnoses, especially among the young

New adult diagnoses were consistently more frequent in Sweden than in the UK, but UK rates climbed steeply after 2020. In the UK, the rate rose from 6 to 64 per 100,000 people between 2010 and 2023. In Sweden it increased from 43 to 65 per 100,000 between 2010 and 2021.

The steepest increases were among 16-20-year-olds. In the UK, their rate rose from 31 to 364 per 100,000, and in Sweden from 165 to 361. Growth was also fastest among females in both countries, among people of white ethnicity in the UK and among those with Swedish-born parents in Sweden.

Age-standardised prevalence was higher in males throughout, but rose in both sexes. In 2023 it reached 1.4% of males and 0.7% of females in the UK. In Sweden in 2021 the figures were 1.8% and 1.2%. Among 16-20-year-olds, prevalence was 4.1% in both countries at the end of the study periods.

A changing clinical picture

The proportion of newly diagnosed adults with earlier epilepsy, psychosis or intellectual disability fell over time, while the proportion with earlier ADHD, anxiety, depression and other mental health conditions grew. In the UK, a history of epilepsy among newly diagnosed adults dropped from 10% to 4% between 2010 and 2023, while a history of anxiety rose from 29% to just over 58%. The trends were broadly similar in men and women.

Limitations and what comes next

The study is observational and cannot establish why the profile has shifted. The authors state that the data cannot show whether the change reflects better recognition of more subtle presentations of autism or the misclassification of other psychiatric conditions as autism. Because the work relies on recorded diagnoses, it also reflects who is assessed and how, not underlying prevalence alone.

For researchers, the consistent direction of change in two different health systems suggests that findings from older autism cohorts may not describe adults diagnosed today. Studies of outcomes, co-occurring conditions and service needs may need to account for the year of diagnosis. The authors conclude that support should be developed for the needs of this changing population. Distinguishing the drivers of the trend, such as diagnostic criteria, referral pathways and awareness, is a clear priority for future work.

Source: Major changes discovered in medical profiles of adults diagnosed with autism since 2010 (Medical Xpress, 4 November 2026).

Image: AI-generated illustration.