ADHD might remain underdiagnosed in England despite recent surge in recorded cases

A recent study published in The Lancet Regional Health – Europe suggests that attention-deficit/hyperactivity disorder remains substantially underdiagnosed in England, despite a recent surge in recognized cases. By analyzing millions of medical records, researchers found that the rate of formal diagnoses falls far below expected global averages, especially among older adults. These findings highlight an ongoing need for better access to diagnostic services across all age groups.

Attention-deficit/hyperactivity disorder, commonly known as ADHD, is a neurodevelopmental condition. It involves 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 detailed behavioral assessments and developmental histories.

In recent years, public awareness of ADHD has expanded significantly. This increased visibility has led to a rise in people seeking formal assessments in the United Kingdom and globally. Because of this high demand, wait times for clinical evaluations have stretched to several years in some regions.

This growing demand has prompted public debates and media reports questioning whether the condition is being overdiagnosed. Some commentators have expressed concern about the rapid rise in assessment referrals. However, actual population-wide data on real-world diagnostic rates in England had been historically lacking.

“Public awareness of ADHD has grown considerably, alongside rising numbers of people seeking assessment, but we did not have a clear national picture of how often ADHD is actually diagnosed across different age groups in England,” said Amber John, a senior lecturer in psychology at the University of Liverpool and a lead author of the study. “We wanted to understand how diagnosis rates have changed over time and whether particular groups may still be missing out on recognition and support.”

To address this gap in knowledge, the authors of the new study sought to establish a precise understanding of current diagnostic rates across different demographics. They aimed to determine the exact proportion of the population with a recorded diagnosis. They also wanted to compare these real-world healthcare records to established global estimates of how common ADHD actually is.

Global meta-analyses, which combine data from multiple large studies, suggest that about five to eight percent of children and around two to six percent of adults have ADHD. By comparing England’s recorded medical data against these global benchmarks, the scientists hoped to determine if the recent rise in diagnoses reflects an over-medicalization of normal behavior or merely a delayed recognition of existing cases.

To conduct their analysis, the scientists utilized a massive database called the Clinical Practice Research Datalink Aurum. This system contains routinely collected electronic health records from primary care practices across England. The database is broadly representative of the general English population in terms of age, sex, and geographic 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, used to determine the total proportion of people currently diagnosed, included 3,536,476 patients. These individuals were actively registered with their primary care physician as of June 30, 2025. The researchers identified patients with ADHD by searching for specific diagnostic codes or prescriptions for ADHD medications.

The second group, designed to track new diagnoses over a twenty-four-year period, was much larger. It included 42,241,788 patients who contributed medical data between the years 2000 and 2024. For this portion of the study, the scientists calculated the incidence rate, which refers to the number of newly recorded cases per one thousand people over a specific time frame. To measure this precisely, they used a metric called person-years, which accounts for both the number of people in the study and the amount of time each person was observed.

The data revealed that the overall point prevalence of recorded ADHD in mid-2025 was just 1.19 percent. Point prevalence simply means the percentage of people in a given population who have a specific condition at a single point in time. The rate was slightly higher in males, at 1.48 percent, compared to females, at 0.91 percent.

Diagnosis rates also varied significantly by age. The highest prevalence was found in young adults aged 18 to 24, where 3.60 percent of males and 2.07 percent of females had a recorded diagnosis. From that point onward, the likelihood of having an ADHD diagnosis decreased steadily as patient age increased. For adults aged 65 and older, the recorded prevalence was only 0.05 percent for both males and females.

When the researchers compared these recorded figures to the expected global prevalence estimates, they found a substantial gap. For example, among males aged 18 to 24, the recorded diagnosis rate was roughly 28 percent lower than expected based on global averages. This gap widened significantly for older age groups. For individuals aged 65 and older, the recorded diagnosis rate was over 93 percent lower than global estimates.

“Recorded ADHD diagnoses have increased over time, particularly since 2020, but ADHD remains under-recognized across the lifespan,” John explained. “The gap was especially striking among middle-aged and older adults: very few older people had ADHD recorded in their primary-care records.”

This pattern suggests that older adults with ADHD are largely going unrecognized in the English healthcare system. “This is unlikely to mean that ADHD simply disappears with age,” John added. “Instead, many people may have grown up at a time when ADHD was poorly understood and reached later life without ever being recognized.”

The analysis of new diagnoses between 2000 and 2024 showed marked changes over time. Between 2001 and 2009, the rate of new ADHD cases remained low and stable. Starting in 2010, the incidence rate began to climb steadily as public awareness campaigns gained traction.

A sharp acceleration in new diagnoses occurred from 2021 onward. The rate of new cases per one thousand person-years jumped from 1.03 in 2021 to 2.53 by 2024. The highest rates of new diagnoses consistently occurred in males under the age of 18.

The researchers noted a specific age gradient in the rate of acceleration from 2020 onward. The biggest increases in new incidence rates were observed in young adults, followed by middle-aged adults, and finally older people. Meanwhile, incidence rates for the oldest group, those aged 65 and older, remained almost completely flat and very low across the entire follow-up period.

“I was struck by how low and stable the rate of newly recorded ADHD remained amongst people aged 65 and over, even while rates increased sharply in younger groups,” John said. “Although awareness of ADHD in adulthood has grown, this suggests that older generations may not yet have benefited to the same extent.”

However, the data also indicated a recent spike in general adult diagnoses. Between 2020 and 2022, the rate of newly recorded cases increased across most adult age groups under 65, particularly among females. This trend tends to reflect a closing of the historical gap where females were less likely to receive a diagnosis during childhood due to differences in how their symptoms presented.

Interpreting these findings requires keeping several limitations and caveats in mind. The study relied on primary care medical records, which introduces the possibility of misclassification. Some patients may have received a diagnosis from a private specialist that was not subsequently entered into their 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. “It is likely to reflect a combination of improved awareness, changing recognition and greater demand for assessment.”

The global reference estimates used for comparison also present a potential issue. These expected rates were drawn from international studies that used varying methods to assess ADHD symptoms, ranging from formal clinical interviews to self-reported questionnaires. Because these benchmarks are global, they might not perfectly mirror the true underlying prevalence specific to the English population.

“Our data capture ADHD recorded in primary-care records rather than every person who meets diagnostic criteria,” John added. “Our estimates of possible under-recognition were based on comparisons with prevalence estimates from previous research, so they should be viewed as indicative rather than exact.”

Not everyone with ADHD characteristics requires or desires a formal medical diagnosis. Some individuals may function well without clinical intervention or prefer to manage their traits outside of a medical framework. This means that expected population prevalence estimates might naturally be slightly higher than clinical diagnosis rates in a real-world setting.

The database also lacked details regarding certain demographic factors. The researchers were unable to analyze the data based on socioeconomic status, ethnicity, or gender identity. Future research examining these specific variables could help identify whether certain marginalized communities face disproportionate barriers to receiving an ADHD evaluation.

Looking ahead, the research team hopes to investigate the long-term outcomes and healthcare experiences of those who do receive a formal evaluation.

“We now want to understand what happens after diagnosis, including whether people with ADHD can access appropriate healthcare and support and whether this differs by age, gender and other characteristics,” John said. “A major focus of my current work is ADHD in people aged 50 and over, a group that has historically been largely absent from both research and service provision.”

Meeting the growing demand for assessments will require healthcare systems to adjust their capacity. The authors note that the current lack of resources contributes to lengthy wait times, leaving many individuals without necessary support. Expanding access to specialized diagnostic services could help bridge the gap between actual prevalence and recorded diagnoses.

“Ultimately, we hope this work will help inform accessible, adequately resourced ADHD services across the whole lifespan,” John stated. “Greater recognition is important, but diagnosis alone is not the endpoint. People need timely access to assessment as well as meaningful support after diagnosis, and services will need sufficient resources to meet that need.”

The study, “Attention-Deficit/Hyperactivity Disorder in Children and Adults in England, 2000–2025: Recorded Prevalence and Diagnostic Trends in a Population-Based Observational Study Using Routinely Collected Primary Care Data,” was authored by Amber John, Gavin R. Stewart, William Mandy, Celine El Baou, Elizabeth O’Nions, Lucy Corrigan, Henry Shelford, Rob Saunders, Douglas G.J. McKechnie, Jae Won Suh, Georgia Pavlopoulou, Philip Asherson, Jessica Agnew-Blais, and Josh Stott.