September 9, 2026

expert reaction to study of changes in characteristics associated with ADHD and Autism Spectrum Disorder diagnoses over time

Scientists comment on study in JAMA Psychiatry on changes in characteristics associated with ADHD and Autism Spectrum Disorder diagnoses over time.

Dr Steven Kapp, Senior Lecturer in Psychology, University of Portsmouth, said:

“This study adds little conclusive data to debates about autism and ADHD diagnoses because it did not measure the degree of core traits (“symptoms”) or disability. It also relied on the World Health Organization’s ICD-10 diagnoses, which are outdated, especially for countries like the U.S. that rely on the American Psychiatric Association’s DSM-5. For example, the DSM-5 narrowed ¹who qualifies for an autism diagnosis, and rates are no longer rising²in the U.S. for boys and men. This study does suggest that as public and professional awareness grow (especially among more educated families), more girls are recognized, as are people whose struggles become more obvious in adolescence with growing demands for social interaction and decision-making (which autism and ADHD affect).

“Women and girls have been known for about 100 years³ to have subtler but not necessarily “milder” challenges for conditions like autism, but awareness⁴and diagnostic practices⁵ are only beginning to catch up.”

References:

[1] https://link.springer.com/article/10.1007/s10803-014-2065-2

[2] https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2851930

[3] https://pmc.ncbi.nlm.nih.gov/articles/PMC10038965/

[4] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0337600

[5] https://link.springer.com/article/10.1186/s13229-026-00724-1

Dr Joanna Martin, Senior Research Fellow, Cardiff University’s School of Medicine, said:

“This new study is of high quality, applying robust methods to analyse health data from a large and representative population sample in Denmark.

“Given similarities between Denmark and the UK in terms of national health services and similar increases in ADHD and ASD diagnoses over recent years, these results are likely to be relevant to the UK as well.

“The results support other research which indicates that the recent increase in diagnoses of ADHD and ASD in children and young people in high income countries like Denmark and the UK is linked to better clinical recognition of these conditions in a broader group of children and young people.

“The new research suggests that children and young people without certain early life or socioeconomic risk markers (such as preterm birth or low maternal education) are more likely to be diagnosed with ADHD and ASD in more recent years.

“The authors appropriately caution that their study does not indicate that ADHD and ASD in children and young people have less functional impact for individuals these days; indeed, research at Cardiff University and elsewhere suggests that the impact of ADHD symptoms in children has actually increased over time.

“These identified changing population trends in the characteristics of children and young people who get a diagnosis of ADHD and/or ASD suggest that more young people who need support are now being recognised and offered the treatment and support they need.”

Prof Dame Uta Frith, Emeritus Professor of Cognitive Development, UCL, said:

“This is a sound population study which offers further evidence that ADHD and ASD diagnoses have changed over the past decade. As numbers of diagnoses have climbed, newly diagnosed individuals look far more like their unaffected peers and fit less well with previously established risk profiles. The implication of this is that the proportion of mild cases is increasing and severely affected individuals become less visible, but measures of symptom severity would be needed to confirm this.”

‘Changes in Characteristics Associated With ADHD and ASD Diagnoses Over Time’ by Magnus Elias Tarp et al. was published in JAMA Psychiatry at 16:00 UK time on Wednesday 9th September.

DOI: 10.1001/jamapsychiatry.2026.2722

Declared interests

Dr Steven Kapp: “I have no interests to declare”

Dr Joanna Martin: Joanna Martin is an editor at JCPP Advances.

Prof Dame Uta Frith: “I don’t have a conflict of interest.”