A major review has concluded that Attention Deficit Hyperactivity Disorder (ADHD) is significantly underdiagnosed in the UK, leaving millions without access to crucial support.
The comprehensive study, published in the British Journal of Psychiatry and led by a team of 32 experts including clinicians and academics, found no evidence to suggest that ADHD is overdiagnosed in the country. On the contrary, the team warned that alarmist claims around overdiagnosis may prevent people with legitimate conditions from receiving care.
The review estimates that roughly one in 20 children (5.4%) and 3.3% of adults in the UK have ADHD. While diagnoses in clinical settings have risen between 2000 and 2018—likely reflecting increased awareness—researchers emphasize that rates still fall far below the condition’s actual prevalence.
Professor Samuele Cortese of the University of Southampton, the study’s lead author, said: “We are diagnosing more ADHD than in the past decade, but there are still many individuals with the condition who remain undiagnosed. The rise in diagnosis shows increased awareness, but it does not meet the full demand for care.”
The review also acknowledged that misdiagnoses can occur due to low-quality assessments or poor adherence to national guidelines, but stressed that these cases do not offset the broader problem of underdiagnosis.
Experts highlighted the risks for untreated ADHD, including accidents, substance misuse, mental health struggles, and increased mortality. Professor Tamsin Ford, co-author and head of psychiatry at the University of Cambridge, said: “Overdiagnosis is not the issue; the challenge is that many remain undiagnosed and unsupported, often pushed into private care due to long NHS waiting lists.”
Currently, adults seeking an ADHD diagnosis in the UK may face waits of several years, with around 200,000 adults on NHS waiting lists. Diagnosis requires evidence of symptoms affecting daily life and persisting since childhood, as ADHD cannot develop for the first time in adulthood.
The review comes amid rising public awareness, with several UK celebrities—including Lily Allen and Robbie Williams—recently sharing their ADHD diagnoses.
In response to growing demand, Health Secretary Wes Streeting launched an independent review into mental health, ADHD, and autism services, aiming to ensure timely, evidence-based access to diagnosis and care.
ADHD UK estimates that more than two million people in the UK are living with undiagnosed ADHD. The charity provides information on diagnostic pathways and ongoing support for individuals and families affected by the condition.
