Is ADHD overdiagnosed in the UK?

The number of people in the UK seeking an assessment for ADHD is reported to have increased dramatically in recent years. This has led some commentators to suggest that ADHD is now ‘overdiagnosed’. Is there any truth to this, or are there legitimate reasons for the increase in people seeking an ADHD diagnosis?

Many studies have investigated the prevalence of ADHD in adult populations, and there is broad agreement that around 2.5% of adults have ADHD. It is likely that the vast majority of these adults are undiagnosed. In general, treatment rates for ADHD are far lower than would be expected for the number of people who likely have the disorder.

Rates of medication use for ADHD in adults were reported to be just 0.05% of the UK population in 2018. A recent report suggests that this figure has risen to 0.3% of the population and that an estimated 170,000 patients were prescribed at least one stimulant medication for ADHD between July and September 2022. This number includes children and adults. Not all patients with ADHD use medication, however, whether stimulant medication or not, so the likely number of adults diagnosed with ADHD is difficult to estimate accurately.

In reality, expected treatment rates should be around 1% or more of adults, even if only the most severe cases were treated.

Why has the number of people seeking an ADHD diagnosis increased?

There are several plausible reasons for the increase in adults seeking an ADHD diagnosis since 2019. Firstly, the effects of lockdown during the Covid-19 pandemic were shown to have a greater impact on the mental health and well-being of children and adolescents with ADHD than the general population.  It is therefore likely that this would extend to undiagnosed adults, leading to more people seeking a diagnosis.

Alongside this, the rise of social media platforms such as TikTok, where ADHD is the 7^th highest trending hashtag, has raised awareness of the disorder. Finally, celebrities and influencers announcing their ADHD diagnoses have further added to public awareness.

So, with more people seeking assessment for ADHD, it is hard to say ADHD is being “over-diagnosed”.  The number of people diagnosed, or the proportion of people given a diagnosis who seek assessment is not a useful metric to decide if ADHD is overdiagnosed.  The robustness and quality of each individual assessment should be considered instead.

There is no robust evidence that ADHD is overdiagnosed in adults. The combination of increased public awareness of ADHD symptoms, plus the impact of lockdowns has led to the increases that have been observed. Adults with ADHD can be vulnerable, and can question their diagnosis. Recent media articles suggesting that ADHD is overdiagnosed are unhelpful to the ADHD community and potentially perpetuate persistent stigma and myths about the disorder.

Author: Dr Adam Joiner

Editor: James Brown, PhD.