A stark diagnosis gap leaves older adults missing from England’s rapidly rising ADHD figures

ADHD diagnoses have risen sharply across England, yet a new study suggests thousands of older adults may still be passing through life without recognition or support.

Researchers from UCL, the University of Liverpool and King’s College London examined primary care records to understand how Attention Deficit Hyperactivity Disorder is being identified across different age groups.

Their findings reveal a striking divide. New diagnoses increased after 2020 in most groups, with the highest rates among boys under 18. Among adults, the rise was particularly noticeable in women.

For people aged 65 and over, however, the picture barely changed.

Only 0.05 per cent of men and women in that age group had an ADHD diagnosis recorded in their primary care notes. Researchers warned that the exceptionally low figure should not be taken as proof that ADHD is rare in later life.

Instead, it may reflect decades of limited awareness and unequal access to assessment. Many older people grew up before clinicians, schools and families widely recognised ADHD, leaving symptoms unexplained and support out of reach.

Dr Amber John, who began the research at UCL before moving to the University of Liverpool, said the low diagnosis rate among older adults could stem from those historical differences rather than a genuine absence of the condition.

The study, published in The Lancet Regional Health Europe, found that 1.19 per cent of people in England had an ADHD diagnosis in their primary care record.

That proportion remained well below international estimates, suggesting ADHD affects between 3 and 5 per cent of the population. Researchers identified a gap between recorded diagnoses and estimated prevalence in every age group, but the divide was most severe among older adults.

The team used anonymised information from more than 3.5 million people registered with GP practices in England during 2025. They compared the proportion with a recorded diagnosis against prevalence estimates drawn from international research.

They also analysed records from more than 42 million patients to track diagnostic trends between 2000 and 2024.

The results showed substantial growth in ADHD recognition over the past decade. NHS figures cited alongside the findings estimate that roughly 2.5 million people in England have ADHD, including people who have not received a formal diagnosis.

Demand for assessments has also placed growing pressure on services. Yet the researchers argue that rising numbers should not hide the people who remain missing from official records.

Dr Gavin Stewart, a British Academy Research Fellow at King’s College London, said the comparison uncovered a substantial gap across every age group. He warned that many older adults may have lived without their ADHD ever being recognised.

A diagnosis can provide a route to appropriate help, understanding and practical support. Without it, people may spend years blaming themselves for difficulties affecting education, employment, organisation, relationships and everyday life.

Dr Angela Hind, chief executive of the Medical Research Foundation, said ADHD can have a profound effect across several areas of a person’s life and may exist alongside other neurodevelopmental conditions.

She said people who remain undiagnosed or unsupported can struggle for years without understanding the challenges they face.

The findings do not establish exactly how many older adults have undiagnosed ADHD. They do, however, expose an unusually wide difference between recorded diagnoses and expected prevalence.

As recognition grows among children and younger adults, the study leaves a troubling question hanging over an older generation. How many people reached retirement age without ever being offered an explanation for lifelong difficulties?

Researchers say stronger ADHD services could help more children and adults receive recognition and support. Without that progress, the increase in diagnoses may continue to conceal one of the system’s deepest blind spots.