ADHD Is Not Being Over-Diagnosed In The UK, Say Experts

In 2025, Health Secretary Wes Streeting said he’d launch an independent review into increased demand for autism, mental health, and ADHD services.

Per the BBC, this will involve looking for “evidence of over-diagnosis” – a concern others have raised in previous headlines.

But ADHD UK estimates that about two million cases of ADHD are undiagnosed. “Just one in nine people with ADHD in the UK actually have a diagnosis,” their site reads.

And a new paper, authored by dozens of academics, carers, clinicians, and people with lived experience with ADHD, has said that “There is no evidence that ADHD is over-diagnosed in the UK”.

Instead, they argue that “available data point to under-diagnosis,” and that the narrative suggesting ADHD is over-diagnosed could further block those with the condition from much-needed diagnosis and care.

It’s common to hear ”‘Nowadays everyone has ADHD,’” the paper, published in the British Journal of Psychology, said.

But the authors think it’s important to focus on the empirical data here.

They noted that ADHD rates are generally consistent across the globe, with the most recent research from 204 countries suggesting ADHD prevalence is about 5.4% among under-18s.

A meta-analysis found the rates are roughly 3.3% for adults.

Demand for ADHD diagnoses and care has indeed risen in the UK in recent years. But in 2018 in the UK, “administrative prevalence was 2.5% in boys and 0.7% in girls, and 0.7% in men and 0.2% in women” – far under expected rates.

The authors note this data hasn’t been available since the pandemic.

But “pre-pandemic data suggest that it has remained substantially below the ADHD population prevalence in the UK, providing no evidence at present that ADHD is over-diagnosed at a population level.”

It would take an enormous increase in diagnoses and treatment to, eg, get that 0.2% figure in adult women to its potential 3.3% rate (the number of adult women who meet the diagnostic criteria for ADHD is far closer to men’s than girls have historically been to boys).

Meanwhile, in 2023 (post-pandemic), 24% of those surveyed who were waiting for an NHS ADHD assessment had been doing so for one to two years. 10% had been waiting for two to three years.

The NHS has recently made cuts to ADHD assessments.

The study’s lead author, Professor Samuele Cortese, told Cambridge University: “While misdiagnosis and inappropriate diagnosis do occur, the available evidence indicates that underdiagnosis and under-treatment remain the predominant challenges”.

And senior co-author of the study, Professor Tamsin Ford, added, “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 Cortese also pointed out the potential economic and personal costs associated with these undiagnosed rates.

“They include increased risk of academic failure, suicidal behaviour, substance abuse, criminality, injury and death,” he said.

“The failure to provide treatments which have been shown to reduce these risks represents a major ethical issue that needs to be urgently addressed.”