Stolen Focus — Chapter no 13

13

Cause Eleven: The Rise of ADHD and

How We Are Responding to It

Something strange started to happen around fifteen years ago, when my nephews were small. Their teachers believed that large numbers of kids in their classes were becoming more restless and unable to focus. They didn’t want to sit still or attend to their lessons. Around this time, an idea that didn’t exist in Britain when I was a child – or, at least, was exceptionally rare – started to spread through the country.

It was argued by some researchers and doctors that these children had a biological disorder, and that is why they weren’t paying attention. This idea proliferated with incredible speed across the English-speaking world. Between 2003 and 2011 alone, diagnoses of attention deficit hyperactivity disorder (ADHD) soared in the United States by 43 percent overall, and by 55 percent among girls.

It has now reached the point that 13 percent of adolescents in the US have been given this diagnosis, and of them, a majority are given powerful stimulant drugs as a result.

In Britain, the increase has also been extraordinary: for every child who was diagnosed with ADHD when I was seven years old, in 1986, there are now one hundred kids in this position. Between 1998

and 2004 alone, the number of children being given stimulants doubled.

When it comes to our own attention problems as adults, we often readily acknowledge a whole range of influences on us – the rise of invasive technologies, stress, lack of sleep, and so on. But when our children face the same challenges, over the past twenty years we have been drawn to a starkly simple story: that this problem is largely the result of a biological disorder. I wanted to investigate this in depth. Of all the chapters in this book, this is the one I’ve found hardest to write, because it’s the topic about which serious scientists disagree the most. By interviewing them, I learned that they don’t agree on even the most basic questions – including whether ADHD actually exists in the way most people have been told it does, as a biological illness. So I want to go through this chapter slowly and carefully. This is the topic where I interviewed the most experts – over thirty of them – and I kept going back with more questions for a long time.

But I want to make clear a few things at the start that every expert I spoke with agreed on: everyone being diagnosed with ADHD has a real problem. They aren’t making it up or faking it. Whatever the cause, if you or your child is struggling to focus, it’s not your fault: you’re not incompetent or undisciplined or any of the other stigmatising labels that might have been applied to you. You deserve compassion and practical help to find solutions. Most experts believed that for some children, there can be a biological contribution to their poor focus – though they disagreed on how large a contribution that was. We should be able to have a calm and honest conversation about the other aspects of the ADHD controversy while holding these truths in our minds.

The question of whether kids who can’t focus have a biological problem is, in fact, a fairly new debate, and it has changed a lot in the past few years. In 1952 the American Psychiatric Association first wrote a guide to all the things that can go wrong with a person’s mental health, and the idea that kids who struggle to focus are suffering from a biological disorder was not included. By 1968, the idea had gained enough popularity among psychiatrists that they added it, but they believed it applied to a tiny number of children.

With each passing year, the number of kids identified as having this problem has soared, to the point that in many parts of the South in the United States, 30 percent of boys are now diagnosed with ADHD by the time they turn eighteen. As I write, it is swelling even further – huge numbers of adults are now being told they have this disability, with over 3 million of them already being prescribed stimulants. The market for prescribing stimulants is now worth at least $10 billion.

As all this has exploded, a polarised argument has broken out over it. On one side, there are people saying ADHD is a disorder caused overwhelmingly by something going wrong within the individual’s genes and brain, and that very large numbers of children and adults should be taking these stimulants to treat it. This side has largely prevailed in the US. On the other side, there are people saying that attention problems are real and painful, but it is incorrect and harmful to see them as a biological disorder that requires the mass prescription of drugs, and we should be offering different forms of help. This side has largely prevailed in places like Finland.

Let’s start with the purely biological story, and why so many people find truth and relief in it. One day, on an Amtrak train, I got talking to a woman who asked me what I did for a job. When I told her I was writing a book about why people struggle to pay attention, she started to tell me about her son. I didn’t write it down at the time, so I

only remember the broad details of what she said – but he had a typical experience. Years before, he had been really struggling at school – he wasn’t able to pay attention in class, and he was in trouble a lot. She felt concerned for him, and judged by the other parents. Finally, the school’s teachers urged her to take him to the doctor. Their doctor spoke to her son and then told her that he had diagnosed him with ADHD. He told her that it meant her son had different genetics from other kids, and that as a result, he had developed a different kind of brain, one that wasn’t like most people’s. This meant he found it much harder to sit still and focus.

Stephen Hinshaw, a professor of psychology at Stanford University, similarly told me that genetics account for ‘75 to 80 percent’ of ADHD, a ballpark figure that is based on a large series of scientific studies.

It’s distressing to be told your child has a disability. She felt shocked – but at the same time as they are offered this message, parents are also told lots of positive things: your son’s behaviour isn’t your fault. In fact, you deserve sympathy: you’ve been coping with something really hard. And best of all, there is a solution. Her son was prescribed the stimulant drug Ritalin. When he started to take it, he stopped being so restless and bouncing off the walls. He said he didn’t like how it made him feel, though – one child I know told me that he felt like his brain was turned off when he took the drug – so his mother felt genuinely conflicted. Ultimately, she decided to continue to give him the stimulants until he turned eighteen, because she felt that at least this would stop him being thrown out of school.

There’s no dramatic aspect to this story: he didn’t have a heart attack or start using meth. On balance, she thought she was doing the right thing.

I feel a lot of sympathy for her. But there are several reasons why I also feel worried about the fact that there are more and more people like her, who now believe this is an overwhelmingly genetic problem that needs to be dealt with primarily with stimulants. I think the best

way to start to explain why might be to step sideways for a moment, and to look at what happened when the concept of ADHD spread beyond kids, and even beyond adults, to a whole new category of living creatures.

One day in the 1990s, a nine-year-old beagle named Emma was led into a vet’s surgery. Her stressed-out owner explained that she had a problem. The dog was anxious all the time – she ate constantly, and there were times when she would suddenly go ballistic, ricocheting off the walls and barking incessantly. If she was left alone in the house, the dog would freak out even more. The owner kept using one word to describe Emma: hyperactive. She implored the vet to help her figure out what to do.

The vet she had come to see was a man named Nicholas Dodman, an English immigrant who – over a thirty-year career – had become one of the leading veterinary specialists in the United States, and a professor at Tufts University. At first, Nicholas prescribed for Emma and her owner to go to dog training, where both of them could learn new skills to help them interact. It worked – but not completely. The owner said Emma’s problems dipped by around 30 percent. When he heard this, Nicholas decided that Emma in fact had ADHD – a concept that, until he made his own breakthroughs in interpreting animal behaviour, had only really been applied to humans. He prescribed the stimulant drug Ritalin for the dog, and told Emma’s owner to smush it into her food twice daily.

When she came back not long afterwards, the owner was thrilled.

The problem, she said, was solved. The dog had stopped bouncing around the house and trying to eat all the time. It was true that Emma still howled terribly when she was left alone, but otherwise, she was the dog her owner had always hoped for.

By the time I met Nicholas at his home in Massachusetts, this had become a normal day at his clinic. He regularly prescribes Ritalin and other stimulants to animals he diagnoses as having ADHD.

Nicholas is a pioneer, and he’s been called the ‘Pied Piper’ of drugging animals for psychiatric problems.

I was curious about how he came to take this position. He told me it all began quite by accident, like many scientific breakthroughs. In the mid-1980s he was called as a vet to visit a horse named Poker, who had a problem. Poker was obsessively ‘cribbing’ – a terrible compulsive behaviour that around 8 percent of horses develop when they are shut away in stalls for most of the day. It’s an awkward repetitive action, where the horse will grasp with his teeth onto something solid – like the fence in front of him – then arch his neck, swallow, and grunt hard. He’ll do this again and again, compulsively.

The so-called treatments for cribbing at that time were shockingly cruel. Sometimes vets would drill holes into the horse’s face so he couldn’t suck in air, or they would put brass rings in the horse’s lips so he couldn’t grasp the fence. Nicholas was appalled by these practices, and in his search for alternatives, he suddenly had an idea. What if we gave this horse a drug? He decided to inject the horse with naloxone, which is an opioid-blocker. ‘Within a few minutes, the horse just completely stopped,’ he told me. ‘The owner was like, “Oh my God. Oh my God.” ’ After about twenty minutes the horse started cribbing again, but ‘we repeated that [injection] many times with many different horses subsequently, and had exactly the same result’. He said: ‘It fascinated me that you could change behaviour so dramatically by changing brain chemistry … You know, that changed my career.’ From that point on, Nicholas began to believe you could solve the problems of many animals by responding to them in ways that, until then, had only been applied to humans. For example, he was consulted by Calgary Zoo about a polar bear that was endlessly pacing, and he recommended giving it a massive dose of Prozac. It

stopped pacing and began to sit docilely in its cage. Today, thanks in part to Nicholas’s shift in perspective, there are parrots on Xanax and Valium, there are many species from chickens to walruses being given anti-psychotics, and there are cats on Prozac. One of the staff at a leading US zoo told a reporter that psychiatric drugs are ‘definitely a wonderful management tool, and that’s how we look at them. To be able to just take the edge off puts us a little more at ease.’ Nearly half of all zoos in the US now admit giving psychiatric drugs to their animals, and 50 to 60 percent of the owners who come to Nicholas’s clinic are seeking psychiatric meds for their pets. At times, it sounds like One Flew Over the Cuckoo’s Nest for actual cuckoos.

Before I went to meet Nicholas, I expected him to justify this in one particular way. I thought he would tell me the story that lots of doctors tell parents who have kids with attention problems – that this is a disorder with biological causes, and this is why they need biological solutions in the form of drugs. But he didn’t say that. In fact, his explanation started where his own journey into this science had begun – with cribbing horses. ‘No one’s ever seen a horse in the wild do this. This is a condition of “domestication”, keeping horses in unnatural situations,’ he told me. ‘If they’d never been put in a stall, and they’d never been subjected to that psychological pressure early on, they wouldn’t develop it.’ As he described what happened to these horses, he used a phrase that struck me. He said these horses are suffering from ‘frustrated biological objectives’. Horses want to roam and run and graze. When they can’t express their innate nature, their behaviour and focus go awry, and they start to act out. He told me that ‘the pressure of having your biological objectives thwarted is such that it opens a Pandora’s box’, where you’ll try to find any behaviour that will ‘alleviate this crushing psychological pressure or inability to do anything … Horses spend about 60 percent of their time in the wild

grazing, so it’s not surprising that one of the things that gives them release is a sort of fake grazing, which is what cribbing is.’ He admitted freely that his approach of drugging animals for what’s dubbed ‘zoochosis’ – the madness animals often develop when they are caged – is an extremely limited solution. I asked him if, for example, drugging the polar bear had solved his problem. ‘No,’ he replied. ‘It’s a Band-aid. The problem is you’ve taken a polar bear out of the polar environment, and you’ve stuck it in a zoo … Polar bears in nature will walk for miles across the Arctic tundra. They look for seal places, and they swim, and they eat seals. The exhibit [the cage where this polar bear was trapped] is nothing like real life. So, just like the guy in jail, they pace to appease the inner pain of being denied a real life … They’ve got all these instincts that are all intact, that they’re unable to utilise.’ The long-term solution is to shut down zoos, he said, and to let all animals live in an environment that is compatible with their natures.

He told me about a dog that was unable to focus on anything and spent all its time obsessively chasing its own tail. It lived in a tiny apartment in Manhattan. Then, one day, its owners split up, and it was sent to live on a farm upstate – and its tail-chasing and apparent focus problems went away. All dogs should run for at least an hour off-leash every day, but ‘not many’ pet dogs in the US get that, he told me. They’re frustrated, and it causes problems.

He can’t magic that world into existence by himself. In the absence of those long-term solutions, he wanted to know, what would I have him do? We discussed this for a long time. I tried to explain to him that while I saw where he was coming from, I felt instinctively uncomfortable with it. These animals are showing these behaviours as a way of expressing distress – Poker the horse hated being shut away, and Emma the beagle hated being left alone, because horses need to run and dogs need a pack. I was worried that by muffling their signals with drugs, he might be encouraging their owners into a kind of fantasy – that they could take a creature, ignore its nature,

and make it live a life that fits the owner’s needs, not the animal’s, without any cost. We need to hear the animal’s distress, not suppress it.

He listened thoughtfully, and responded by describing to me pigs who live and die in brutal factory farms, ripped from their mothers as babies, spending their whole lives in carts where they can’t turn around. He asked: ‘I could make this pig a lot better and tolerate this intolerable situation with less psychological pain if I was to put Prozac in the drinking line. Would you be against that?’ But the choices he was confronting me with, I said, with shouldn’t exist. His hypothetical concedes too much – it takes a dysfunctional environment for granted, and assumes that all we can do is try to adapt to it and take the edge off. We need better choices than that. ‘I mean – reality shouldn’t be the choice,’ he replied. ‘It’s what we have, you know? So you have to work with what you’ve got.’

I began to ask myself – is there any way in which children who struggle to focus are like Emma the beagle, and are being medicated for what is in fact an environmental problem? I learned that scientists fiercely disagree about this. We do know that the huge rise in children being diagnosed with attention problems has coincided with several other big changes in the way children live. Kids are now allowed to run around far less – instead of playing in the streets and in their neighbourhoods, they now spend almost all their time inside their homes or school classrooms. Children are now fed a very different diet – one that lacks many nutrients needed for brain development, and is full of sugars and dyes that negatively affect attention. Children’s schooling has changed, so it now focuses almost entirely on preparing them for high-stress testing, with very little space for nurturing their curiosity. Is it a coincidence that ADHD diagnoses are rising at the same time as these big changes, or is

there a connection? I’ve already discussed the evidence that our dramatic changes in diet and rise in pollution are causing a rise in children’s attention problems, and I’ll come to the evidence about how the other changes might be affecting children’s attention in the next chapter.

I want to start, though, with somebody who has pioneered a different way of responding to ADHD in children. Across three years, I repeatedly interviewed Dr Sami Timimi, who is a leading child psychiatrist in Britain, and one of the most prominent and vocal critics in the world of the way we talk about ADHD today. I went to see him in Lincoln, a town that was built over a thousand years ago around a cathedral and seems to have been sighing back into the earth ever since. The old parts of the town have been taken over by chain stores paying minimum wage, and when Sami moved there he discovered his practice was full of people who were really struggling, through no fault of their own, with low wages and little hope. He could see that people in Lincoln needed a lot of practical help – but he was surprised to find that people seemed to expect one thing from him. They thought, as he put it, ‘That a psychiatrist was basically somebody who does medication,’ and he was treated as a pill-dispenser. He inherited from his predecessor twenty-seven kids who were being prescribed stimulant drugs for ADHD, and local schools were pressing for more kids to be put on them. It would have been easy for Sami to just carry on with this approach.

But he was pensive. He believed that if he was going to take his responsibility as a doctor to these kids seriously, he had to take time to look in depth at their lives and their environments. One of the children who had been diagnosed with ADHD and given stimulants by Sami’s predecessor was an eleven-year-old boy, who he called Michael to protect his confidentiality. After he was dragged into Sami’s office by his mother, Michael refused to even talk to him. He just sat there, angrily sulking, as his mother explained that she didn’t know what to do. She said that Michael kept kicking off at school,

refusing to focus and becoming aggressive. As she explained all this, Michael kept interrupting her, sullenly demanding to leave.

Sami refused to decide anything based on just one session. He felt he needed to learn more – so he kept interviewing this mother and son over a period of several months. He wanted to understand when these problems began. As he probed into this, it slowly emerged that two years before, Michael’s dad had moved to another town, and he hardly ever talked to his son any more. It was in the aftermath of this that Michael started acting up at school. Sami wondered if he felt rejected. Sami told me: ‘When you’re a child, you’re not developed intellectually to take a step back and look at things from a more rational, objective point of view … When a father says they’re going to come and see you, but they never turn up, you imagine it’s because there’s something wrong with you. It’s because they don’t want to see you. It’s because you’re not very nice. It’s because you cause problems.’ So one day, Sami decided to phone Michael’s dad. He agreed that he would come into the doctor’s office to see Sami, and they talked over the situation. The father was chastened, and decided to come back into his son’s life in a structured and consistent way. Sami called Michael in and told him that there was nothing wrong with him.

It wasn’t his fault his dad had disengaged. He didn’t have a disorder.

He had been let down, and that wasn’t his fault. Now it was going to change. As Michael reconnected with his dad, over several months they weaned him off his stimulant drugs. Sami did this gradually because the withdrawal effects can be severe and terrible. As time passed, several things changed for Michael. He had a male role model. He knew he wasn’t a bad person who drove his dad away.

He stopped acting out at school and started learning again. Sami felt he had identified the underlying problem and solved it – and so the attention problems gradually went away.

Another of the kids brought to Sami was a nine-year-old boy he called Aden, who behaved well at home, but seemed to be behaving

badly at school. His teacher said he was hyperactive and kept distracting the other kids, and was urging that he be given stimulants. Sami decided to visit the school, and he was appalled by what he saw. Aden’s teacher spent all her time yelling at the class to be quiet, and irrationally punishing Aden and a few other kids she seemed to have taken a dislike to. The classroom was in chaos, and Aden was being blamed. At first, Sami tried to help the teacher to change her story about Aden, but she wouldn’t listen, so he helped Aden’s parents move him to a new, less chaotic school. Once he got settled in, he started to thrive, and his attention problems also faded.

Sami does still occasionally continue the prescription of stimulants to children, but it’s rare, it’s short term, and it’s after trying all other options. He said that with the vast majority of cases of kids with attention problems that come into his office, if he listens carefully and offers practical support to change the child’s environment, it almost always reduces or ends the problem they have.

He told me that when people hear a child has been diagnosed with ADHD, they often imagine this is like a diagnosis of, say, pneumonia – that a doctor has identified an underlying pathogen or illness, and is now going to prescribe something that can deal with that physical problem. But with ADHD, there are no physical tests a doctor can carry out. All she can do is talk to the child, and people who know the child, and see if the kid’s behaviour matches a checklist drawn up by psychiatrists. That’s it. He says: ‘ADHD is not a diagnosis. It’s not a diagnosis. It’s just a description of certain behaviours that sometimes occur together. That’s all it is.’ All you are saying, when a child has been diagnosed with ADHD, is that a child is struggling to focus. ‘It doesn’t tell you anything about the “why” question.’ It’s like being told that a child has a cough, listening to the cough, and then saying – yes, the child has a cough. If a doctor identifies a child with attention problems, that should be the first step in the process – not the last.

I was moved by Sami’s experiences – but I also asked: how do we know if this kind of approach – listening to the child, and trying to solve the underlying problem – actually works, beyond these moving anecdotes? I dug deeply into this question. It turns out there’s a huge number of studies investigating what happens when you give children stimulant drugs (I’ll come to the results of them soon). There are some studies into what happens when you give parenting classes on how to set boundaries, give consistent feedback, and so on (the evidence is mixed, but you often see a mild improvement).

But I wanted to know – is there any research into what happens when you intervene in the way Sami does?

It turned out that – so far as I could uncover – in the whole world, there seemed to be only one group of scientists who had studied something close to this question, in a remarkable long-term study, so I went to Minneapolis, where they conducted their research, to meet them. In 1973, Alan Sroufe, who became a professor of child psychology there, started a massive collective research project, which was designed to answer a really big question – what factors in your life really shape you? We met in the café of a garden centre in the city’s suburbs. Alan is a gentle, softly spoken scientist who, at the end of our conversation, went to pick up his grandchildren from school. For more than forty years, Alan and his team have been studying the same 200 people, who were all born into poor families.

They have been tracked and analysed from birth all the way into middle age. These scientists measured a huge range of factors in these people’s lives – from their bodies to their home lives, from their personalities to their parents. One of the many things they wanted to figure out is: what factors in a person’s life can lead to them developing attention problems?

At the start, Alan was fairly confident about the answer they would find. He believed – like most scientists at the time – that ADHD was caused entirely by some inborn biological problem in the child’s brain, so he was sure one of the most important measures they took

would be of the child’s neurological status at birth. They also measured the baby’s temperament in its first few months, and then, over time, they measured all sorts of other things – like how stressful their parents’ lives were, and how much social support the family got.

His eye was keenly fixed on those neurological measures.

By the time the kids were three and a half, the scientists started to make predictions about which of them would develop ADHD. They wanted to see: which factors made it more likely? Alan was startled by what they found, as the kids got older and some were indeed diagnosed with attention problems. It turned out their neurological status at birth didn’t help at all in predicting which kids would develop serious attention problems. So what did? They discovered ‘the surrounding context is the most important thing’, Alan told me, and a crucial factor was ‘the amount of chaos in the environment’. If a child is raised in an environment where there is a lot of stress, they are significantly more likely to then develop attention problems and be diagnosed with ADHD. It turns out that the elevated levels of stress in their parents’ lives usually came first. He told me: ‘You could see it unfolding.’ But why would a child growing up in a stressful environment be more likely to have this problem? I of course thought back to everything I had learned from Nadine Burke Harris. Alan began to offer an additional layer of explanation – one that is compatible with her findings. He explained that when you’re very young, if you get upset or angry, you need an adult to soothe you, and calm you down. Over time, as you grow up, if you are soothed enough, you learn to soothe yourself. You internalise the reassurance and relaxation your family gave to you. But stressed-out parents, through no fault of their own, find it harder to soothe their children – because they are so amped-up themselves. That means that their children don’t learn how to calm and centre themselves in the same way.

Their kids are, as a result, more likely to respond to difficult situations by getting angry or distressed – feelings that wreck their

focus. To give an extreme example, he said to me – you try being evicted from your apartment, and then giving your child all the soothing she needs that night. He added – it’s not just poverty that causes this – middle-class parents struggle with stress too. He told me: ‘Many parents are currently overwhelmed with their life circumstances, such that they cannot provide a stable and calm and supportive environment for their children.’ The worst response to this discovery is to ‘point fingers at the parents’. That only causes more stress, and more problems for the kids, and misses the truth: ‘Those parents were doing the best they could. I guarantee you they loved their children.’ Parenting takes place in an environment – and if that environment floods parents with stress, it will inevitably affect their children.

After gathering evidence on this for decades, Alan concluded that ‘none of what I originally believed turned out to be true’, and a ‘clear majority’ of the kids who were later diagnosed ‘were not born to be ADHD. They developed these problems in reaction to their circumstances.’ There was one crucial question, Alan said, that held the key to whether parents overcame these problems – one that seemed to me to tell us a lot about Sami’s work. It was: ‘Is there somebody giving you support?’ The families they studied sometimes got help from people around them. It usually wasn’t from a professional – they just found a supportive partner, or a group of friends. When their social support went up in this way, they found ‘the children are less likely to have problems at the next stage’. Why would this be? Alan wrote: ‘Parents experiencing less stress can be more responsive to their infants; then infants can become more secure.’ This effect was so large that ‘the strongest predictor of positive change was an increase in social support available to the parents during the intervening years.’ Social support is, I reflected, the main thing Sami provides to families whose children struggle with attention.

Yet there’s a challenge here. There is no question that when you give a child a stimulant like Adderall or Ritalin, their attention will significantly improve in the short term. All the experts I interviewed, wherever they stand on this debate, agreed with this, and I’ve seen it for myself. I knew a little boy who was constantly running around, shouting, and bouncing off the walls, who – when given Ritalin – sat still and was able to look people in the eye with a steady gaze for the first time in his life. The evidence is clear that this effect is real, and due to the drugs. I have plenty of adult friends who use stimulants when they have to blitz a work project, and it has the same effect on them. In Los Angeles in 2019, I caught up with my friend Laurie Penny, who is a British writer on various TV shows there, and she told me she uses prescribed stimulants when she wants to do a big writing job because they help her to concentrate. This seems to me like a reasonable decision for adults to take.

But there is a reason why most doctors across the world are very cautious about prescribing stimulant drugs to children, and no country (with the solitary exception of Israel) comes close to prescribing them as freely as the US.

My concerns about this started to crystallise when I met with a woman named Nadine Ezard, who is the clinical director of alcohol and drug services at St Vincent’s Hospital in Sydney. She’s a doctor who works with people who have addiction problems, and by the time we met in 2015, Aussies were in the middle of a severe spike in methamphetamine addiction. For a while, doctors weren’t sure how to respond. With heroin, there is a drug they could legally prescribe to addicted people that’s a reasonable substitute, methadone – though with meth, there didn’t seem to be one. So Nadine – along with a group of other doctors – was part of a crucial experiment, licensed by the government. They started to give people addicted to

meth a stimulant that is prescribed over a million times a year in the US for kids with ADHD – dextroamphetamine.

At the time that I spoke with her, they had already tried it with fifty people, and the results of a bigger experiment are going to be published after this book comes out. She told me that when they are given these stimulants, the people addicted to meth seemed to feel less craving, because it scratched some of the same itch: ‘They say that when they first start on it, it’s the first time in a long time their brain hasn’t been focused completely on meth. That they suddenly feel this freedom.’ Speaking about one patient, she recalled: ‘He would be thinking about meth constantly. He’d be in the supermarket, [or] wherever, [and] his constant decision making would be – “Am I going to have enough money left to buy crystal?”

And then [giving him dextroamphetamine] relieved him from that.’ She compared it to giving nicotine patches to smokers.

She is not the only scientist discovering the similarities between methamphetamine and the other amphetamines the US routinely prescribes to children. Later, I went to see Carl Hart, professor of psychology at Columbia University, who had conducted experiments giving Adderall to people who were addicted to meth. When they were given in similar ways in the lab, these people with long- standing meth addictions responded in almost identical ways to Adderall and meth.

Nadine’s programme is a thoughtful, compassionate way to treat people with meth addictions – but I felt unsettled to learn that the drugs we give kids turn out to be a reasonable proxy for meth. Sami told me: ‘It’s a bit bizarre when you start realising that we are prescribing legally the same substances that you are saying on the other hand are very dangerous to take if you take them illicitly … They’re chemically similar. They work in a similar way. They work on very similar neurotransmitters.’ But – as Nadine stressed to me – there are some important differences. They give higher doses to people recovering from meth addiction than children are given for

ADHD. They give them as pills, which releases them more slowly into your brain than smoking or injecting. And street drugs – because they are banned and have to be sold by criminals – contain all sorts of contaminants that aren’t in the pills you get from a pharmacist. But still, it made me resolve to research the mass prescription of this drug to children some more.

For years, lots of parents were told that you could figure out if your child has ADHD in a straightforward way, related to these drugs.

Many doctors told them that a normal child would become manic and high if they were given these pills, whereas an ADHD kid would slow down, focus and pay attention. But when scientists actually gave these drugs both to kids with attention problems and kids without attention problems, this turned out to be wrong. All children – indeed, all people – given Ritalin focus and pay attention better for a while.

The fact the drug works isn’t evidence that you had an underlying biological problem all along – it’s just proof that you are taking a stimulant. This is why, during the Second World War, radar operators were given stimulants by the army – it made it easier for them to continue to focus on the very boring job of watching a mostly unchanging screen. It’s also why people who snort a line of stimulants then become very boring and go off on long monologues – they become very focused on their own train of thought, and filter out the bored-to-tears look on your face.

There is scientific evidence that there are several risks associated with giving these drugs to kids. The first risk associated with these drugs is physical – there is evidence that taking stimulants stunts a child’s growth. Kids taking a standard dose are about three centimetres shorter, over a three-year period, than they would have otherwise been. Several scientists have also warned that stimulants increase the risk of a child having heart problems and dying as a

result. Obviously, heart problems are rare among children – but when millions of kids are taking these drugs, even a small increase in risk means a real rise in deaths.

But James Li, assistant professor of psychology, who I went to see at the University of Wisconsin in Madison, told me about what I found to be the most worrying thing. He explained: ‘We simply don’t know the long-term effects. That’s a fact.’ Most people assume – I certainly did – that these drugs have been tested and found to be safe, but he explained ‘there hasn’t been a lot of research done on long-term consequences to brain development’. This is especially concerning, he says, since ‘we’re so quick to give them to young kids. Kids are our most vulnerable population, because their brains are developing … These are drugs that operate directly on the brain, right? It’s not an antibiotic.’ He showed me that the best long-term research we have is in animal studies – where the findings are sobering. I read them, and they show that if you give adolescent rats Ritalin for three weeks – which is the equivalent of giving it to a human for several years – you find that the striatum, a crucial part of the brain that deals with experiencing rewards, shrinks significantly in adolescent rats. He said that you can’t assume that these drugs will affect humans the same way they affect rats, and he stressed there are some benefits to taking these drugs – but we need to be aware ‘there’s the benefit, and there’s the risk. What we currently operate under is the short- term benefit.’ When I interviewed other scientists, I also learned that the positive effects of these drugs – while real – are surprisingly limited. At New York University, Xavier Castellanos – a professor of child and adolescent psychiatry – explained to me that the best research on the effects of stimulants found something important. They improve a child’s behaviour on tasks that require repetition, but they do not improve their learning. I frankly didn’t believe him, but then I went and looked it up in the study that the supporters of stimulant

prescription had directed me to as the gold standard on ADHD research. After fourteen months on stimulants, kids performed 1.8 percent better on academic tests. But kids who for the same amount of time were simply given guidance on their behaviour improved by 1.6 percent.

Just as critically, the evidence suggests that the initial positive effects of stimulants don’t last. Anyone who takes stimulants develops tolerance for the drug – your body gets used to it, so you need a higher dose to get the same effect. Eventually, you hit the maximum dose kids are allowed to take.

One of the most alarmed scientists I spoke with was Dr Charles Czeisler, the sleep expert at Harvard Medical School, who told me that one of the main effects of taking stimulants is that you sleep less. This, he explained, has very worrying implications for the development of young people’s brains – particularly all the young people he sees using them so they can study longer and longer hours. ‘The pushing of all these amphetamines for these kids reminds me of the opioid crisis, except nobody’s talking about it,’ he said. ‘When I was a kid, if people gave me amphetamines, sold them to children, they would go to jail. But just like the opioid crisis … nobody does anything about it. It’s a dirty little secret in our society.’ Most of the scientists I interviewed in the US – and I talked with a lot of the most prestigious experts on ADHD – told me that they believe prescribing stimulants is safe and provides a lot of benefits that outweigh the risks. Indeed, many US scientists argue that presenting the counterarguments – as I am doing here – is actively dangerous: it will, they say, make parents less likely to bring their kids forward to be prescribed stimulants, and as a result, those children will needlessly suffer and do worse in their lives. They also believe it may make some people quit these drugs abruptly, which is dangerous – they could go through a horrible physical withdrawal.

But in the rest of the world, scientific opinion is more divided, and it’s

more common to hear scepticism or outright opposition to this approach.

There is one decisive reason why many people – like the woman I met on the Amtrak – are persuaded that their child’s attention problems are largely the result of a physical disorder. It is because they have been told that this is a problem caused primarily by their child’s genetic make-up. As I mentioned before, Professor Stephen Hinshaw told me that genes explain ‘75 to 80 percent’ of the problem, and even higher figures are often put forward. If this is a mainly biological problem, then a mainly biological solution intuitively makes sense – and the kind of interventions Sami and others argue for can only ever be additional extras. When I dug into this, I came to believe that the truth is complicated – and doesn’t really fit with the strident claims of either side of this polarised debate.

I was keen to understand: where do these statistics showing that a very high percentage of ADHD is caused by a genetic disorder come from? I was surprised to learn, from the scientists who put these statistics forward, that they do not come from any direct analysis of the human genome. Almost all of it comes from a much simpler method, known as twin studies. They take a pair of identical twins. If one of them has been diagnosed with ADHD, they ask, Has the other twin been diagnosed with it too? Then they take a pair of non- identical twins. If one of them has been diagnosed with ADHD, they ask, Has the other twin been diagnosed with it? They then repeat this many times, until they have a big enough sample, and they compare the figures.

The reason they do this is simple. All sets of twins in these studies – whether they are identical or not – grow up in the same home, with the same family, so they figure if you find a difference between the two types of twin, they reason, it can’t be down to their environment.

The difference has to be explained instead by their genes. Identical twins are much more genetically similar to each other than non- identical twins, so if you discover that something is more common among identical twins, the scientists conclude there’s a genetic component. You can figure how much is determined by genes by seeing how big this gap is. This method has been used for years by all sorts of highly reputable scientists.

Whenever scientists investigate ADHD in this way, they always find that identical twins are much more likely to both be diagnosed than non-identical twins. Over twenty studies have found this result – it’s consistent. This is where the very high odds on ADHD being genetically determined come from.

But a small group of scientists have been asking if there is a serious problem with this technique. I spoke with one of the people who has made this case in the greatest scientific detail, Dr Jay Joseph, who is a psychologist in Oakland, California. He talked me through the facts. It has been proven – in a different set of scientific studies – that identical twins do not actually experience the same environments as non-identical twins. Identical twins spend more time together than non-identical twins. They are treated more alike – by their parents, friends and schools (indeed, often people can’t tell them apart). They are more likely to become confused about their identity and to feel merged with their twin. They are psychologically closer. Jay told me that in most respects, ‘their environment’s more similar … They’re copying each other’s behaviour more. They’re being treated more alike. All of these things lead to more similar behaviour – whatever the behaviour may be.’ So, he explained, there is something other than genes that could explain the gap that’s showing up in all these studies. It could be accounted for by the fact that ‘identical twins grow up in a much more similar behaviour-shaping environment than non-identical twins.’ Their attention problems may be more alike not because their genes are more similar, but because their lives are more similar. If

there are factors in the environment causing attention problems, identical twins are more likely to both experience them to the same extent than non-identical twins. So, he explains, ‘Twin studies are unable to disentangle the potential influences of genes and environment.’ This means the statistics we often hear – of 75 to 80 percent of ADHD being due to genetics, for example – are built on an unreliable foundation. Such figures are, Jay says, ‘misleading, and misunderstood’.

It seemed to me implausible that so many prominent scientists would draw on this technique if it was so flawed. I was conscious that in my previous books, I drew on evidence from twin studies myself. But when I asked some scientists who argue that ADHD is primarily genetically driven about the flaws in these studies, many of them readily conceded that these criticisms have some legitimacy, in a way that was disarming. Usually, they would then simply switch the conversation onto other reasons why we should believe this is a genetically based problem. (I’ll come to them in a moment.) I came to believe that twin studies are a kind of zombie technique, which people keep referencing even though they know they can’t fully defend it, because it tells us what we want to hear – that this problem is mostly in our kids’ genes.

When you set aside these twin studies, Professor James Li told me, ‘time after time, every single study’ looking at the role any individual gene plays in causing ADHD finds that ‘no matter how you measure [it], it is always small. The effect of the environment is always bigger.’ So as I absorbed all this, I began to ask myself – does this mean genes play no role in ADHD? There are some people who get close to arguing this – and that is where I think the ADHD-sceptics go too far.

James explained to me that although the twin studies overestimate the role of genes, there’s a new technique called SNP heritability, which figures out how much of a characteristic is genetically driven by using a different method from twin studies. Instead of comparing

types of twin, these studies compare the genetic make-up of two totally unrelated people. It could pluck, say, you and me, and see whether match-ups in genes between us correlate with a problem we might both have – like (say) depression or obesity or ADHD. These studies currently find that around 20 to 30 percent of attention problems relate to your genes. James told me that this is a new way of studying the question and it only looks at common variation genes, so in the end the proportion caused by our genetics might end up being somewhat more than that. So it’s wrong, he explained, to dismiss a genetic component – but it’s also wrong to say it’s all or most of the problem.

One of the people who most helped me to understand some aspects of these questions was Professor Joel Nigg, who I interviewed at Oregon Health and Science University in Portland. He is the former president of the International Society for Research in Child and Adolescent Psychopathology, and a leading figure in this field.

He told me it used to be thought that some kids were simply wired by their genes to be different and to develop different brains. But – as he has written – now ‘the science has moved on’. The latest research shows that ‘genes aren’t destiny; rather they affect probability.’ Alan Sroufe, who did the long-term study into what factors cause ADHD, said the same: ‘Genes don’t operate in a vacuum. That’s the main thing we’ve learned from gene studies … Genes are turned on and off in response to environmental input.’ As Joel puts it, ‘our experiences literally get under our skin’ and change how our genes are expressed.

To help me think about how this works, Joel offered me an analogy. He explains: ‘If your child is tired and run down, she will catch a cold at school more easily in the winter. She is more susceptible’ – but ‘if there was no cold virus’, then neither an

exhausted kid nor a well-rested one would get a cold. Similarly, your genes might make you more vulnerable to a trigger in the environment – but there still has to be a trigger in the environment.

He writes: ‘In some ways, the truly big news about ADHD today is that we’ve revived our interest in the environment.’ Joel believes there is some role for stimulants. He says that in a bad situation, he believes they are better than nothing, and can give kids and parents some real relief. ‘I’m splinting a broken bone in a battlefield. I’m not healing it, you know? But at least the guy can walk off, even if he might have a crooked leg the rest of his life.’ But if we are going to do that, he said, we crucially also need to ask: ‘Where is the problem located? Do we need to look at what our kids are facing?’ He says that kids at the moment face many large forces that we know harm their attention – stress, poor nutrition, pollution: all things I was going to investigate more after learning about them from him. ‘I would say we should not accept those things. We should not accept that our kids have to grow up in a chemical soup [of pollutants], for example. We shouldn’t accept that they have to grow up with grocery stores that hardly have any food in them that’s really food … That should change … For some kids, there’s actually something wrong with them because their environment has injured them. In that case, it’s a bit criminal to say nothing more than, in effect, “Let’s placate them with medications so that they can cope with this damaging environment we’ve created.”

How is that different from giving sedatives to prisoners so they can handle being in prison?’ He believes you can only ethically give out drugs if you are also at the same time trying to solve the deeper problem.

He looked sombre, and said: ‘There’s the old metaphor that … villagers are at the river one day, and they notice a dead body come floating down the river. So they do the right thing. They take it out and they give it an appropriate burial. The next day two bodies come down the river and they do the appropriate thing and they bury the

bodies. This goes on for a while, and finally they start to wonder – I wonder where these bodies are coming down the river [from], and if we should do something to stop that? So they go up the river to find out.’ He leaned forward in his chair and said: ‘We can treat these kids – but sooner or later, we need to figure out why is this happening.’ I realised it was time for me to go upriver.