King's College London

The research, which is the first systematic review of ADHD prevalence to be published since the start of the COVID-19 pandemic, highlighted the poor quality of studies available for inclusion. Despite this, the best quality data found no significant rise in the prevalence of ADHD.

A total of 40 studies were included in this review. All included studies presented original data collected between January 2020 and February 2024 from the general global population.

An analysis of the best quality data suggested that the rate of diagnosis of ADHD continues to vary internationally. In the USA, between 9.6 per cent and 10.5 per cent of children aged 3-17 years have been diagnosed1, compared to 7.5 per cent of 288,248 children and emerging adults aged 1-24 years in Canada, and 3.2 per cent of 70,437 children aged 0-17 years in Sweden.

Recent studies that suggested higher rates of ADHD diagnosis were of low quality, using only self-reporting surveys, or parent/teacher reported symptoms, not clinical diagnoses.

Dr Alex Martin, Lecturer in Psychology at King’s IoPPN and the study’s first author said,

“The media has been concerned about a ‘surge’ in ADHD diagnoses for several years. While assessments and help-seeking may be increasing, our study has shown significant gaps in the tracking of ADHD prevalence, resulting in a frustratingly unclear picture.

“The best data we have suggests that there has been no meaningful increase in ADHD prevalence, but most of the research is too biased to draw conclusions from.

“When data is not updated, or isn't reliable, scientists cannot complete high quality research. This causes problems for healthcare policy makers internationally and means that services which are already under pressure may encounter increased demand without receiving additional support”.

Anecdotal reports suggest that the UK has seen an unprecedented rise in the number of children and adults seeking support for ADHD. The demand has exacerbated pressures on public services and increased already significant backlogs of people awaiting assessment. In the UK, a survey by the Petitions Committee in 2023 found that approximately 1 in 4 of those who responded face delays of up to two years for an assessment, while 1 in 10 are facing waits that exceed two years.

Dr Samantha Brooks, post-doctoral researcher at King’s College London and the study’s senior author said, “Between January and May 2024, there were 25,080 media articles published on ADHD compared to 5,775 articles in the same period in 2014, with publications rising notably in 2020 and peaking in early 2023.

“What we cannot account for, which is perhaps the biggest outstanding question, is why there has been an unprecedented increase in the number of people seeking help for ADHD.”

The changing prevalence of ADHD? A systematic review (DOI10.1016/j.jad.2025.119427) (Alex F Martin, G James Rubin, M Brooke Rogers, Simon Wessely, Neil Greenberg, Charlotte E Hall, Angie Pitt, Poppy Ellis Logan, Rebecca Lucas, Samantha K Brooks) was published in the Journal of Affective Disorders.