Experts are warning that far from being over-diagnosed, people with ADHD are waiting too long for assessment, support and treatment.
In a paper, published today in the British Journal of Psychiatry, a group of experts say there is no robust evidence that ADHD is over-diagnosed in the UK. They refute the view that ‘nowadays everyone has ADHD’, which is gaining traction in public discourse and has been amplified by some leading politicians, as demand rises for NHS assessments and services.
Overdiagnosis is not a problem, but misdiagnosis may be as people are driven into the private sector by long waits, and sadly, missed diagnoses remain common
- Tamsin Ford
Bringing together academics, clinicians, people with lived experience and carers, the group say this narrative risks misleading the public and policymakers and overshadows a more pressing concern - unmet need.
Professor Tamsin Ford, Head of the Department of Psychiatry at the University of Cambridge, senior co-author on the paper, said: “While many more people with ADHD are being recognised and treated, we are failing to support many more. Overdiagnosis is not a problem, but misdiagnosis may be as people are driven into the private sector by long waits; and sadly, missed diagnoses remain common.”
Professor Samuele Cortese from the University of Southampton, the study’s first author, said: “Rather than focusing on increases or decreases in diagnostic rates, attention should be directed toward the extent to which those with ADHD are being adequately diagnosed and treated.
“While misdiagnosis and inappropriate diagnosis do occur, the available evidence indicates that under-diagnosis and under-treatment remain the predominant challenges.”
When standardised diagnostic criteria are applied, the prevalence of ADHD internationally is around 5 per cent in children and 3 per cent in adults.
While prevalence has increased over time, NHS administrative data in England remains substantially below these expected levels, suggesting that many people with ADHD are living without a diagnosis and adequate support.
The group acknowledge that misdiagnosis can occur in some cases, particularly where assessments rely heavily on self-reporting or where alternative conditions are not fully considered.
The researchers stress that the absence of biological diagnostic markers means that thorough, multidisciplinary clinical assessment is essential. Field trials show that when clinicians are properly trained, an ADHD diagnosis is amongst the most reliable for a mental health condition.
Bringing together academics, clinicians, people with lived experience and carers, the group say this narrative risks misleading the public and policymakers and overshadows a more pressing concern - unmet need.
Professor Tamsin Ford, Head of the Department of Psychiatry at the University of Cambridge, senior co-author on the paper, said: “While many more people with ADHD are being recognised and treated, we are failing to support many more. Overdiagnosis is not a problem, but misdiagnosis may be as people are driven into the private sector by long waits; and sadly, missed diagnoses remain common.”
Professor Samuele Cortese from the University of Southampton, the study’s first author, said: “Rather than focusing on increases or decreases in diagnostic rates, attention should be directed toward the extent to which those with ADHD are being adequately diagnosed and treated.
“While misdiagnosis and inappropriate diagnosis do occur, the available evidence indicates that under-diagnosis and under-treatment remain the predominant challenges.”
When standardised diagnostic criteria are applied, the prevalence of ADHD internationally is around 5 per cent in children and 3 per cent in adults.
While prevalence has increased over time, NHS administrative data in England remains substantially below these expected levels, suggesting that many people with ADHD are living without a diagnosis and adequate support.
The group acknowledge that misdiagnosis can occur in some cases, particularly where assessments rely heavily on self-reporting or where alternative conditions are not fully considered.
The researchers stress that the absence of biological diagnostic markers means that thorough, multidisciplinary clinical assessment is essential. Field trials show that when clinicians are properly trained, an ADHD diagnosis is amongst the most reliable for a mental health condition.
Early detection and intervention have a positive impact on emotions, behaviour, educational attainment and peer relationships, as well as helping children cope with the health care they may need to receive, such as staying in hospital, procedures or operations.
Studies have shown that children with epilepsy have up to six times the population rate of ADHD, yet often have difficulty obtaining treatment but when they are successfully treated there is a significant improvement in functioning and quality of life.
Reference
Cortese, S et al. ADHD (over) diagnosis: fiction, fashion, and failure. British Journal of Psychiatry; 6 March 2026; DOI: 10.1192/bjp.2026.10546
Adapted from a press release from the University of Southampton