"There's a stereotype," Camilla tells me, "which is that if you're not a complete screw-up, you can't have ADHD. It's particularly common among psychiatrists."
She would know. Growing up, Camilla was a model student. She got excellent grades, won a place at medical school and eventually became a psychiatry trainee and researcher.
Then, towards the end of her twenties, everything suddenly came to a halt.
When the stress of a botched medical procedure combined with mounting pressures at work, she found herself burnt out and unable to do her job.
“My brain just stopped working. I was putting orange juice in the washing machine instead of the fridge. I couldn’t figure out the train home and kept ending up in the wrong parts of town.” She ended up taking sick leave.
It was her therapist who first suggested she get an ADHD assessment. “I said, ‘It feels like I’m always trying 100 times harder to be organised and I’m twice as bad as everyone else’’’ and something clicked in the therapist’s mind.
Yet when she went to her GP for a referral, she was told: “You’re a doctor and you’re married, you can’t have ADHD.”
Even though she was working in psychiatry, Camilla herself was unsure. “I thought ADHD was naughty, fidgety boys who couldn’t sit still and failed at school. It just wasn’t me.”
For decades, ADHD was seen as a childhood disorder – marked by restlessness and inattention – that largely faded with age.
Over the last 20 years, however, researchers have challenged this view. Many now see ADHD as a lifelong condition that remains under-recognised. But the idea has proved controversial.
Camilla could see the clues in hindsight. As a child, she flooded the family bathroom four times by forgetting to turn off the tap. “My parents had to re-plaster the ceiling twice.”
Although studious, she often zoned out of conversations and clashed with friends. “I was constantly contravening social rules. I could easily come across as stupid or rude. Most people knew my brain worked differently, there just wasn’t a name for it.”
When, at 28, ‘it’ was finally given a name – attention deficit hyperactivity disorder – everything made sense. “Every part of my life was transformed. My marriage, my friendships, my mental health, my work. Everything.”
I first met Camilla when we worked together in a children’s mental health clinic. I saw firsthand how disabling ADHD could be, how exhausting it was for children to be labelled ‘naughty’.
I also learned that diagnosis wasn’t everything. Many were stuck in a stressful school system that didn’t suit them.
Like some colleagues, I assumed most would eventually ‘grow out of it’, finding a niche in an adult life they could thrive in.
Meanwhile, demand for diagnoses was growing exponentially – driven mainly by adults – fuelled by rising public awareness and social media. NHS clinics were quickly overwhelmed. Waiting times grew from months to years.
I remember feeling uneasy at how quickly ADHD seemed to be changing. And I wasn’t alone. Many clinicians pushed back, especially after the diagnostic criteria were revised in 2013 to make it easier for adults to qualify.
US psychiatrist Prof Allen Frances, who oversaw the previous version of the diagnostic manual in 1991, has since become a prominent critic of the growth in diagnoses.
He sounded the alarm in a recent article: “It’s time to stop the adult ADHD fad before it gains even more traction.”
ADHD is having something of an identity crisis. And it’s not just the public: many professionals are wondering how the diagnosis has stretched so far, so fast.
As both the severity of symptoms and the range of patients have expanded, some are beginning to ask what the label now means.
A chance discovery
Fidgety, distractible children have always existed. But it was a chance discovery that led doctors to first see their behaviour as a medical problem, rather than just a lack of discipline.
In the 1930s, Dr Charles Bradley, a psychiatrist caring for brain-injured children, trialled Benzedrine, a new stimulant drug, to relieve their headaches.
It did nothing for the headaches, but to Bradley’s surprise, many of the behavioural problems the children had developed after their injuries began to settle. They calmed down and focused in class. What’s more, their grades improved.
Bradley published his findings suggesting that hyperactivity might have a neurological basis, but his work was largely ignored for years.
When the diagnosis was formalised in the 1960s, it was called “hyperkinetic reaction of childhood,” reflecting the belief that poor parenting or unstable homes were to blame.
“Psychiatry always had this blame-the-parent thing,” Prof Stephen Faraone, a leading ADHD researcher, says, “and ADHD was no exception.”
Faraone recalls that when he started out in the late 1980s, “Adult ADHD was not on anyone’s radar.” Yet in his children’s clinic, parents often confided they were struggling with the same difficulties as their children.
“We started conducting family studies, which showed that if you looked at the parents of kids with ADHD, you found that they often had it at far higher rates than you would expect.”
Genetic studies later confirmed that ADHD is highly heritable. Around 70–80 per cent of the variation in symptoms can be explained by genes. But when these results were published, they provoked a surprising backlash.
After Prof Anita Thapar, a child psychiatrist, linked ADHD to certain genetic variants, she found herself bombarded with calls and emails.
“One, from a retired head teacher, said children with ADHD should be given the slipper,” she had written.
“Others accused us of being in cahoots with drug companies, of being doctors who ‘just want to drug people.’” (Neither she nor her collaborators were funded by drug companies.)
Another controversy was emerging. While the hyperactivity symptom of ADHD was more common in boys, it seemed to fade with age.
Research, however, showed that it was closely linked with symptoms of inattention and impulsivity, which were just as disabling but harder to spot, so many people slipped under the radar.
For a long time, ADHD was thought of as a boys’ condition, but once inattention and impulsivity were added to the mix, it became clear that girls were affected too.
These less obvious symptoms were tracked as the children grew up and sometimes they improved, like hyperactivity, but just as often they remained.
When Faraone and colleagues proposed in the 1990s that ADHD could last into adulthood, many psychiatrists resisted. “No one would give us space at conferences to discuss our findings.”
Yet when they did finally get space, other clinicians admitted they had often seen the signs; it was just that, up until that point, they didn’t know what to make of them.
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A major public health issue
Could adult ADHD really have been hiding in plain sight?
Researchers had begun to use new methods to look for mental health problems, studying not just the patients in clinics, but whole populations.
“Clinicians don’t really have a great sense of what’s going on in the real world,” Dr Ronald Kessler, the McNeil Family Professor of Health Care Policy at Harvard Medical School says. “They only see what’s happening in their clinics.”
Kessler has done more than almost anyone to change how we look at the long-term effects of mental illness.
In 2001, he ran the National Comorbidity Survey, a study of over 9,000 people in America, which showed that while half of the children seemed to grow out of ADHD, the other half continued to show symptoms.
Further studies confirmed this and today, 3 to 5 per cent of the population are thought to have ADHD.
The World Health Organization commissioned Kessler to repeat these studies in other countries and he found the rate remained strikingly similar wherever he looked, challenging the view many held that ADHD was a peculiarly ‘American disease’.
When these people are followed up through their lives, the consequences are stark. “It’s a feeder disorder,” Kessler says.
“You start to show symptoms of ADHD at the age of eight and they cascade into other problems.” Interpersonal difficulties, for example, can trigger social isolation and depression. Symptoms may become less visible, but the distress remains real.
“All of these studies have looked at the real-world consequences of the disorder,” Faraone says. “Traffic accidents, injuries, substance misuse, unemployment, suicide, criminal convictions – all more likely with undiagnosed ADHD.”
One recent study suggested that people with ADHD live, on average, nine years less.
Even apparently successful adults still show difficulties.
“I’ve had patients who are lawyers or doctors – some clinicians refuse to treat them,” Faraone says. Yet, in his research, he found that high-IQ adults with ADHD had higher divorce rates and lower incomes than their peers without the condition.
I thought of Camilla. “There’s a very functional doctor that people see [when they look at me],” she had told me. “But they don’t see the part at the end of the day that’s completely exhausted from compensating. It’s embarrassing to say out loud, but it’s the truth.”
In the UK, untreated ADHD is estimated to cost £17 billion a year in healthcare and welfare. Policymakers around the world have started to frame it as a major public health issue – especially since it’s treatable.
“ADHD medications are the most effective drugs in psychiatry,” Prof Samuele Cortese, a leading researcher of neurodevelopmental disorders, says. And some of their benefits are only now becoming clear.
In a series of studies published with colleagues in Sweden, Cortese showed that when people with ADHD were treated with medication, many of the associated risks – accidental injury, substance misuse, suicide and overall mortality – were reduced.
It was the first time a psychiatric medication had been shown not just to ease symptoms, but to help prevent future harm.
Differences in the brain
As some researchers realised the scale of ADHD’s effects on a population level, others had begun to pick apart what was happening inside the brain.
After Bradley’s chance discovery of the effects of stimulants, researchers studied the role of the brain’s dopamine system, the main target of these drugs.
Many of the genetic associations with ADHD involved dopamine-related genes and brain-imaging studies showed differences in how dopamine seemed to be regulated in those with the condition.
Because dopamine is central to the brain’s reward system, one theory held that altered dopamine signalling might explain why people with ADHD often struggle to wait, grow impatient with routine tasks or make impulsive decisions.
Yet rather than being explained by ‘low dopamine’ alone, it became clear that larger brain networks were involved.
Scientists identified a set of regions that are active during periods of rest and mind-wandering, but normally quieten down when people engage in goal-directed tasks. They named it the default mode network (DMN), sometimes colloquially called the ‘day-dreaming network’.
Neuroscientists proposed that symptoms might arise from inadequate suppression of this network during daily life. Brain-imaging studies show that in neurotypical individuals, DMN activity falls away as task-focused areas light up.
In people with ADHD, however, the day-dreaming network doesn’t tend to switch off as effectively, interfering with the other task-focused networks.
This may help explain why stray thoughts intrude just when concentration is needed, something that medication can help to reduce.
Still, there was a problem. As scientific understanding shifted, the diagnostic guidelines were stuck with the image of ADHD as a rare childhood disorder. Many experts began to push for change.
“They called in my research along with a number of others,” Faraone recalls, when the American Psychiatric Association formed a new diagnostic task force. “There was a debate whether to create a new ‘adult’ category altogether.”
In the end, the 2013 updated guidance kept a single category, but lowered the threshold for adults by a single point – to account for the waning of hyperactivity.
These changes coincided with surging public awareness, driven in part by destigmatisation campaigns, but also a growing discussion on social media.
#ADHD is now one of the most popular health-related hashtags on TikTok. Yet while these videos can help educate and reduce stigma, a recent study found that most of them provided misleading information.
At the same time, in the UK and elsewhere, clinics were becoming overwhelmed, with demand far outstripping capacity. In some areas, wait times for NHS services are now exceeding four years for children and more than eight for adults.
Amid the crisis, some professionals began to argue that ADHD had all the makings of a fad.
“It’s a case of disease-mongering,” Prof Nassir Ghaemi and Dr Mark Ruffalo, two prominent US clinicians, have recently written, “when a condition that has never been observed is suddenly made popular overnight.”
The UK Health Secretary, Wes Streeting, recently commented that doctors might be “over-diagnosing” ADHD and other mental health conditions, preventing people with them from returning to work.
Yet the noise from social media, and the backlash it has generated, could be obscuring a far larger problem. If 3 to 5 per cent of the population have ADHD, it means that many people remain undiagnosed and untreated.
The UK still lags behind many other European countries, like Denmark and Spain, in rates of diagnosis. And those most likely to miss out are from ethnic minorities and more disadvantaged backgrounds.
Rather than overdiagnosis, it could be the lack of a diagnosis that’s holding many people back from getting on with their lives.
The decision to medicate
When she started work again, Camilla felt apprehensive. “After my diagnosis, I did some coaching and therapy. It helped me be more open about the way my brain works differently and helped me explain to colleagues what I needed.
"It made it easier for my team and much better for my patients. It also took away a lot of the shame.”
Some fear a diagnosis might lead to the overuse of medication, but like many people, Camilla has chosen not to use them. “Medication never made a huge difference for me, but I’ve seen how useful it can be for my patients.”
Cortese tells me that this was now one of the main areas of research, trying to tease apart why some people benefit more from medication than others.
“What’s made the biggest difference,” Camilla says, “is understanding myself – planning my day, sleep, exercise. And having a really supportive husband. That’s probably the best medication!”
Experts increasingly see ADHD as the tail-end of normal human variation. Like height or blood pressure, attention and impulsivity exist on a spectrum, with most of us sitting close to the middle.
“The science clearly shows that these traits lie on a continuum. It’s not black and white,” Cortese says. The challenge is at what point these symptoms are considered a medical problem.
“Traits themselves don’t necessarily cause problems,” but when they continually disrupt daily life – what doctors call ‘functional impairment’, “that’s when we speak of a medical disorder.”
What’s more, as the demands of life change, symptoms can flare up or down. “We tend to see spikes in referrals at certain points in life when people face new challenges,” says Faraone.
“For example, when a family has their first child, or during life transitions like starting a first job or moving to university.”
All of this means that symptoms don’t always need medication, they could be better helped in other ways. In a bid to tackle waiting lists, an NHS task force, chaired by Thapar, recently recommended a radical overhaul of how those with ADHD are supported.
Many people with milder symptoms or ‘traits’ wouldn’t need to see a specialist to begin with, but could be helped with practical advice, skills training and support at universities or workplaces.
If someone is still struggling after this, then they would be referred for a medical diagnosis. It would help to end the waiting-time lottery and relieve the pressure some feel to pay for expensive private assessments.
Still, with long-term consequences now clear, the earlier help begins, the better. “The best situation for any adult,” Thapar says, “is [for the ADHD] to be picked up in preschool. Then they can be supported early before further problems arise.
"There’s quite a lot of evidence that family-focused early-years programmes can help children’s mental health in the long-term.”
Critics still argue that medical labels can be disempowering. Camilla disagrees. “People critique ADHD diagnoses as just an excuse,” she says.
“I’ve had conversations – even with other psychiatrists – who don’t realise that they’re speaking to someone with ADHD. They’ve said some pretty horrible things, calling them attention seekers or just looking to justify bad decisions.”
Yet, for Camilla, it’s not about shirking responsibility, but gaining it.
“I’m not fatalistic. I’ll always have these tendencies, but that doesn’t mean I can’t shape my life. I don’t strive for perfection – I expect mistakes. But now I know I can reduce the chaos, and that makes all the difference.”
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