Recent research published in Lancet Community Health – Europe Attention-deficit/hyperactivity disorder remains underdiagnosed in the UK, despite a recent surge in recognized cases. After analyzing millions of medical records, researchers found that formal diagnosis rates were far below the expected global average, especially among older people. These findings highlight the continuing need for better access to diagnostic services across all age groups.
Attention Deficit/Hyperactivity Disorder, commonly known as ADHD, is a neurodevelopmental condition. This includes persistent patterns of inattention, hyperactivity, and impulsivity that interfere with daily functioning and quality of life. For a diagnosis to be made, these behaviors must be present from an early age and occur in multiple settings, such as both at home and at school or work. Medical professionals typically diagnose this condition using a detailed behavioral assessment and developmental history.
Public awareness of ADHD has expanded significantly in recent years. This increased visibility has led to more people seeking formal recognition in the UK and internationally. This high demand has resulted in wait times for clinical evaluations of several years in some regions.
This increased demand has sparked public debate and media coverage of whether the condition is being overdiagnosed. Some commentators have expressed concern about the rapid increase in evaluation referrals. However, actual population-wide data on the actual diagnosis rate in the UK has historically been lacking.
Amber John, senior lecturer in psychology at the University of Liverpool and lead author of the study, said: “Public awareness of ADHD has increased considerably and the number of people seeking a diagnosis has increased, but there was no clear national picture of how often ADHD is actually diagnosed in different age groups in the UK.” “We wanted to understand how diagnosis rates have changed over time and whether certain groups may still be missing out on recognition and support.”
To address this knowledge gap, the authors of the new study sought to accurately understand current diagnostic rates across different demographics. They aimed to determine the exact proportion of the population for which a diagnosis was recorded. They also wanted to compare these real-world medical records to established global estimates of how common ADHD really is.
A global meta-analysis combining data from multiple large studies suggests that approximately 5 to 8 percent of children and 2 to 6 percent of adults have ADHD. By comparing England’s recorded health data with these global benchmarks, the scientists wanted to determine whether the recent increase in diagnoses reflects the over-medicalization of normal behavior, or simply a delay in recognizing existing cases.
To conduct their analysis, the scientists used a large database called Clinical Practice Research Datalink Aurum. The system contains regularly collected electronic health records from primary care practices across the UK. This database is broadly representative of the general UK population in terms of age, gender and geographical distribution.
The research team created two separate study groups to analyze both the current total number of cases and the rate of new diagnoses over time. The first group was used to determine the total proportion of people currently diagnosed and included 3,536,476 patients. These individuals were actively enrolled with their primary care physician as of June 30, 2025. Researchers identified ADHD patients by searching for specific diagnosis codes or prescriptions for ADHD medications.
The second group was designed to track new diagnoses over 24 years and was much larger. The study included 42,241,788 patients who provided medical data between 2000 and 2024. For this part of the study, the scientists calculated incidence rates. Incidence rate refers to the number of new cases recorded per 1,000 people during a specific period. To accurately measure this, researchers used a metric called person-years. This accounts for both the number of people who participated in the study and the amount of time each person was observed.
According to the data, the overall prevalence of ADHD recorded as of mid-2025 was only 1.19 percent. Point prevalence simply means the proportion of people in a given population who have a particular condition at a given time. This percentage was slightly higher for men at 1.48% compared to 0.91% for women.
Diagnosis rates also vary greatly depending on age. The highest prevalence was among young adults aged 18 to 24 years, with 3.60 percent of men and 2.07 percent of women recording a diagnosis. From that point on, the likelihood of being diagnosed with ADHD steadily decreased as the patient’s age increased. For adults aged 65 years and older, the recorded prevalence was only 0.05% for both men and women.
When researchers compared these recorded numbers with expected global prevalence estimates, they found significant gaps. For example, for men aged 18 to 24, the recorded diagnosis rate was approximately 28% lower than expected based on global averages. This difference widened significantly in older age groups. For individuals aged 65 years and older, the recorded diagnosis rate was more than 93% lower than the global estimate.
“Although recorded ADHD diagnoses have increased over time, especially since 2020, ADHD remains underdiagnosed throughout the lifespan,” John explained. “This difference was particularly pronounced among middle-aged and older adults; very few older adults had ADHD recorded in their primary care records.”
This pattern suggests that older people with ADHD are poorly recognized in the UK healthcare system. “This is unlikely to mean that ADHD simply disappears with age,” John added. “In fact, many people may have grown up in an era when ADHD was not well understood, and may have lived into their later years without it being recognized.”
An analysis of new diagnoses from 2000 to 2024 showed significant changes over time. Between 2001 and 2009, the rate of new ADHD cases remained low and stable. After 2010, public awareness campaigns gained momentum and incidence rates began to rise steadily.
Since 2021, the number of new diagnoses has increased sharply. The rate of new infections per 1,000 person-years jumped from 1.03 in 2021 to 2.53 by 2024. The highest incidence of new diagnoses consistently occurred in men younger than 18 years.
The researchers noted a particular age gradient in acceleration after 2020. The greatest increase in new incidence was observed in young adults, followed by middle-aged adults, and finally older adults. On the other hand, the incidence in the oldest age group, those aged 65 and over, remained almost completely flat and very low throughout the follow-up period.
“We were shocked to find that the rate of newly recorded ADHD among people aged 65 and over remained so low and stable, even though rates were increasing rapidly in younger groups,” John said. “Although awareness of ADHD in adulthood is increasing, this suggests that older generations may not yet benefit to the same extent.”
However, the data also shows a recent surge in common adult diagnoses. From 2020 to 2022, the proportion of newly recorded infections increased in most adult age groups under 65 years, especially among women. This trend tends to reflect a narrowing of the historical gap in which women were less likely to be diagnosed in childhood due to differences in the presentation of symptoms.
Several limitations and caveats should be kept in mind when interpreting these findings. This study relied on primary care medical records, creating the potential for misclassification. Some patients may have received a diagnosis from a private specialist that was not subsequently entered into the general practitioner’s electronic system.
“The increase in recorded diagnoses should not be interpreted as evidence that ADHD itself has suddenly become more common,” John cautioned. “This may reflect increased awareness, changing perceptions and increased demand for assessment.”
Potential problems also exist with the global reference estimates used for comparison. These expected rates were derived from international studies that used a variety of methods to assess ADHD symptoms, ranging from formal clinical interviews to self-report questionnaires. As these benchmarks are global, they may not fully reflect the potential true prevalence specific to the UK population.
“Our data collects ADHD recorded in primary care records, not everyone who meets the diagnostic criteria,” John added. “Our estimates of possible underestimation are based on comparisons with prevalence estimates from previous studies and should therefore be viewed as indicative rather than precise.”
Not all people with ADHD traits need or want a formal medical diagnosis. Some people function well without clinical intervention or prefer to manage their characteristics outside of a medical framework. This means that expected population prevalence estimates may naturally be slightly higher than real-world clinical diagnosis rates.
The database also lacked details regarding certain demographic factors. Researchers were unable to analyze data based on socioeconomic status, ethnicity, or gender identity. Future research examining these specific variables may help identify whether certain marginalized communities face disproportionate barriers to receiving evaluation for ADHD.
Looking to the future, the research team hopes to examine long-term outcomes and medical experiences for those who undergo formal evaluation.
“We now want to understand what happens after diagnosis, including whether people with ADHD receive appropriate medical care and support, and whether this varies by age, gender and other characteristics,” John said. “The main focus of my current research is ADHD in people over the age of 50, who have historically had little involvement in both research and service delivery.”
Health system capacity must be adjusted to meet the growing demand for assessments. The authors note that current resource shortages are resulting in long wait times and are preventing many people from receiving the support they need. Expanding access to specialized diagnostic services can help close the gap between actual prevalence and recorded diagnoses.
“Ultimately, we hope this research will help provide ADHD services that are accessible and well-resourced throughout the lifespan,” John said. “Raising awareness is important, but it’s not just about diagnosis. People need meaningful post-diagnosis support as well as timely access to assessment. Services need sufficient resources to meet that need.”
The study, ‘Attention-deficit/hyperactivity disorder in children and adults in the UK from 2000 to 2025: documenting prevalence and diagnostic trends in a population-based observational study using regularly collected primary care data’, was authored by Amber John, Gavin R. Stewart, William Mundy, Celine El Baou, Elizabeth Onions, Lucy Corrigan, Henry Shelford and Rob. Sanders, Douglas G.J. McKechnie, Jaewon So, Georgia Pavlopoulou, Philip Ascherson, Jessica Agnew-Brace, and Josh Stott.
