6

Attention Deficit

Running from Distraction

I SUSPECT THE first time I realized I was not like my peers was at the early age of three when I discovered no one else in my family or neighborhood was forced to wear a child leash,” wrote Sam, a thirty-six-year-old venture capitalist who came to me in hopes of understanding his lifelong disorder, which was starting to manifest itself in his young son. “I have always been known in the family as the troublemaker and spent most of my childhood in the doghouse and the ‘dunce’ corner. My teachers felt that I had the ability to be a good student but never fully applied myself. I am able to express myself well and organize my thoughts, but often procrastinate.”

Sam is no dunce, but like so many others with attention-deficit/hyperactivity disorder (ADHD), his erratic behavior led everyone around him to label him as stupid or stubborn or spoiled. He didn’t want his son to suffer the same shame, and he was now seeking help at the encouragement of his business partner and his wife. “Neither quite understands how I can function with so much chaos in my life,” he told me.

Chaos, high drama, deadline pressure — acute stress of any form acts like a drug for Sam’s brain. His letter to me outlining his history acknowledges that he had disciplinary problems because he didn’t deal well with authority figures and that he got into drugs at age fourteen. Yet he wasn’t exactly a delinquent. When he turned sixteen, his parents forbade him from getting his driver’s license until he shaped up, and he boosted his GPA from 1.5 to 3.5 almost overnight. Proof, many would argue, that his teachers were right: he just needed to try.

But the problem with Sam wasn’t his attitude. ADHD stems from a malfunction of the brain’s attention system, a diffuse linkage of neurons that hitches together areas controlling arousal, motivation, reward, executive function, and movement. Let’s take one element of the attention system: motivation. While it’s true that people with ADHD “just need to get motivated,” it’s also true that, like every other aspect of our psychology, motivation is biological. What about the child who can’t pay attention in class but can sit perfectly still for hours playing a video game? Or the woman who “spaces out” when her husband is talking but has no trouble focusing on magazine gossip about Brad and Angelina? Obviously, they can pay attention when they want to, right? Not exactly. If we were to look at functional MRI (fMRI) scans of the brains of these people — and scientists have — we would see distinct differences in activity at the reward center in each situation. The reward center is a cluster of dopamine neurons called the nucleus accumbens, which is responsible for doling out pleasure or satisfaction signals to the prefrontal cortex, and thus providing the necessary drive or motivation to focus.

The sort of stimulation that will activate the reward center enough to capture the brain’s attention varies from person to person. What wound up working for Sam was the rigid structure and rigorous physical activity of college athletics — and the desire to prove to everyone back home that he wasn’t stupid. He put himself through school by playing Division III football and lacrosse and made the dean’s list a number of times. “I believe participating in a sporting regimen which required five a.m. practice sessions,” he wrote, “was the turning point that allowed me to see that I could function better in all my endeavors.”

Now he runs several miles every morning and is a partner in a venture capital firm, matching entrepreneurs with big-money investors. In the parlance of this rarefied realm, Sam is what’s known as a rainmaker — a high-energy personality with the social skills and business savvy to make deals happen. When there’s a big one on the table, he has no trouble focusing. The intense pressure allows him to laser in and obsess over every angle, often to the point that the deal consumes all his waking hours.

Paradoxically, the ability to hyperfocus is a common trait of ADHD, and it often leads people to miss the diagnosis because it doesn’t seem to fit. New patients will tell me that they can’t possibly have ADHD since they often get completely absorbed in what they’re reading or doing. But the glitch in the attention system isn’t strictly a deficit — it’s more of an inability to direct attention or to focus on command. I tell my patients a more helpful way to think of ADHD is as an attention variability disorder; the deficit is one of consistency.

Sam gets this. He schedules important work and meetings early in the day, when he can still feel the calming effects of his morning run, knowing that he gets progressively more scattered as the day goes on. As for returning phone calls, if it weren’t for his secretary, it would never happen. He still struggles with most of the core behavioral symptoms that branded him a problem child back in school, but he’s figured out how to manage his ADHD and harness his hyperactivity to some extent, even using it to his advantage. By recognizing his difficulties, he’s been able to arrange his day and his life in such a way that he can be successful.

MASS DISTRACTION

I have coauthored three books about ADHD with my friend and colleague Ned Hallowell. The first, Driven to Distraction, was published in 1994, and as it grew into a bestseller and the broader public became familiar with the general outlines of ADHD, along came the biggest cultural paradigm shift of the century — the World Wide Web. The Internet’s endless stream of distractions would challenge anyone’s attention span.

It’s easy to get distracted in today’s world. It’s become so full of information, noise, and interruptions that all of us feel overwhelmed and unfocused at times. The amount of data in the world is doubling every few years, but our attention system, like the rest of the brain, was built to make sense of the surrounding environment as it existed ten thousand years ago. In our cybercentric world, however, we quickly learn to expect things to happen immediately, and if they don’t, we’re easily frustrated. If our cell phone doesn’t ring or our e-mail Inbox sits empty for more than an hour, we wonder what’s going on. Who has the time or patience to sequence or plan or think things through and evaluate consequences? Why bother, when we can click to the next? It’s no wonder exercise gets pushed to the bottom of the priority list — it requires planning and work.

Experts estimate that just over 4 percent of American adults — that’s thirteen million people — have ADHD, which is not to say that the remaining 96 percent of the population is completely free of attention problems. To a certain degree, everyone suffers from fleeting attention. And as I’ve mentioned, there are varying degrees of severity for many mental health disorders — shadow syndromes, which are personality traits that don’t necessarily meet the full checklist of symptoms doctors rely on to make diagnoses. People with shadows of ADHD might have constant problems with romantic relationships, for example. Or they might succeed in intense, high-energy fields. Or both. They often become entrepreneurs, bond traders, salespeople, emergency room doctors, firefighters, trial lawyers, movie moguls, or advertising executives. These are jobs in which the tendency toward hyperactivity, nonlinear thinking, and risk-taking can lead to great achievements. Sporadic attention can be a real strength in a frenetic setting. People with shadows of ADHD might retain problems with organization, forgetfulness, and personal relationships, but they can get it together when the pressure is on.

There are still those who think the way Sam’s teacher’s did. Because all of us suffer from lapses in attention, it’s easy to assume that all it takes to concentrate is a little effort. I still meet people who believe ADHD is just a matter of laziness or bad child rearing or stupidity or willfulness or hooliganism. Ironically, such skepticism has roots in the medical community itself, which for decades believed that kids magically grew out of ADHD in adolescence. Some of the work I’m most proud of is challenging this conventional wisdom and showing that ADHD exists in adults.

Now, ADHD is the most-studied disorder in medicine, and it’s clearly not an attitude problem. Otherwise it wouldn’t run in families. But according to a study of nearly two thousand Australian identical twins, if one twin has ADHD, there is a 91 percent chance the other one will have it too.

The landmark study proving that ADHD stems from a biological irregularity was published by Alan Zametkin and his colleagues from the National Institute of Mental Health in 1990. Using PET scans to measure brain activity, the study showed that during an attention test, the brains of adults with ADHD work differently from those without ADHD. Zametkin and his colleagues found that the group with ADHD showed 10 percent less brain activity than the control group, and the largest deficit was within the prefrontal cortex, which has a firm hand in regulating behavior. It’s also prone to positive reinforcement through exercise.

SIGNS OF TROUBLE

The phrase “attention-deficit disorder” didn’t even exist until it was introduced in the third edition of the Diagnostic and Statistical Manual in 1980. Since then, we’ve debated whether to establish separate diagnoses for the two primary categories of symptoms — inattention and hyperactivity. Inattention is always part of the disorder, and sometimes hyperactivity is present as well. Hyperactivity is more common in children than adults and especially — though not exclusively — boys, and for years kids with the rambunctious brand of ADHD were the only cases diagnosed. Nobody connected the behavior of hyperactive kids with that of the daydreamers. But the treatment is the same in either case, and now we call the disorder ADHD, regardless of whether hyperactivity is part of the picture.

The hyperactive kids are the ones you can’t miss: they’re the Dennis the Menace characters, bouncing off the walls or fidgeting in their seats, constantly moving — picking at themselves, shaking their legs, doodling, fiddling. Because of their impatience, they intrude and interrupt, blurting things out without thinking. They feel as though they’re always racing, and they finish our sentences because they assume they know what we’re going to say or they’re bored by it. In general, they have a hard time staying on task. They can’t stand playing by themselves and often adopt the role of class clown if they’re having trouble with school. Many of them are socially adept, although they can also act awkwardly because they miss social cues. And, like Sam, they begin to hear early on that they’re screwups. But with many of these kids, it’s plain as day that they need to be moving, and they end up playing sports and doing well. Impulsivity fits in here as a subset of hyperactivity. Children and adults can automatically overreact, negatively or positively, which makes them passionate and quick to anger. Road rage is essentially a temper tantrum, and a red flag for particularly hyperactive forms of ADHD. Just making it through traffic to my office is a trial for some of my patients: “I wish I had howitzers in my headlights!” one woman told me. “I’d blast everyone out of the way!” Impatience feeds this response too. People with ADHD will do anything not to stand in line and can explode if they’re made to wait.

Inattention, or distractibility, is the constant among ADHD symptoms. One couple came in to see me because the wife’s inability to pay attention was undermining their relationship. Although she was a whiz at running an intensive care unit — she thrived on the action — she couldn’t pay attention to her own family. Even as the husband related this in my office, he suddenly said, “Look!” And sure enough, she was staring out the window. ADHD people go off topic and forget ideas and goals and things. One of the classic signs is the pirouette: stepping out the door, the ADHD patient will spin around and go back upstairs to get something she forgot. Everyone does this, of course, but for some of my patients it’s a daily occurrence. The one day the ADHD student does do his homework, he leaves it at home.

The ADHD brain faces a monumental challenge in initiating a task, and it is a master procrastinator. Its owner will sit down to do something she really wants to do and then clean her desk instead. The attention-deficit patient often can’t complete something until the Sword of Damacles is over her head. She has a terrible time organizing things, so her room and office are messy. And she has a love-hate relationship with structure. My patient Sam wasn’t rebelling against authority per se — he was acting out of frustration from his inability to navigate structure.

Paradoxically, one of the best treatment strategies for ADHD involves establishing extremely rigid structure. Over the years, I’ve heard countless parents offer the same observation about their ADHD children: Johnny is so much better when he’s doing tae kwon do. He wasn’t doing his homework, and he was angry, difficult, and problematic; now his best qualities have come out.

You could substitute any of the martial arts here or any highly structured form of exercise such as ballet, figure skating, or gymnastics. Less traditional sports, such as rock climbing, mountain biking, whitewater paddling, and — sorry to tell you, Mom — skateboarding, are also effective in the sense that they require complex movements in the midst of heavy exertion. The combination of challenging the brain and the body has a greater positive impact than aerobic exercise alone. One small study from a graduate student at Hofstra University tested this fact. He found that ADHD boys age eight to eleven participating in martial arts twice a week improved their behavior and performance on a number of measures compared to those on a typical aerobic exercise program (both kinds of exercise led to dramatic improvement over nonactive controls). The kids involved in martial arts finished more of their homework, were better prepared for class, improved their grades, broke fewer rules, and jumped out of their seats less often. In short, they were better able to stay on task.

The technical movements inherent in any of these sports activate a vast array of brain areas that control balance, timing, sequencing, evaluating consequences, switching, error correction, fine motor adjustments, inhibition, and, of course, intense focus and concentration. In the extreme, playing these kinds of sports is a matter of survival — avoiding getting karate chopped, or breaking your neck on the balance beam, or drowning in a swirling pool of whitewater — and thus taps into the focusing power of the fight-or-flight response. When the mind is on high alert, there is plenty of motivation to learn the skills necessary for these activities. As far as the brain is concerned, it’s do or die. And, of course, most of the time we will be in the aerobic range, which boosts our cognitive abilities and makes it easier to absorb new moves and strategies.

COMING THROUGH, LOUD AND UNCLEAR

The attention system doesn’t claim a central address in the brain. Rather, it’s a diffuse web of reciprocal pathways that begins at the locus coeruleus, the arousal center, a part of the brain stem, and sends signals throughout the brain to wake it up and cue our attention. The network engages such areas as the reward center, the limbic system, and the cortex; more recently scientists have included the cerebellum, which governs balance and fluidity. It turns out that there’s a lot of overlap between attention, consciousness, and movement.

The attention circuits are jointly regulated by the neurotransmitters norepinephrine and dopamine, which are so similar on a molecular level that they can plug into each others’ receptors. These are the chemicals targeted by ADHD medications. And of the many genes correlated with the disorder, scientists focus on the ones that regulate these two neurotransmitters. Broadly speaking, the problem for people with ADHD is that their attention system is patchy; they describe it as discontinuous, fragmented, and uncoordinated — problems that can stem from a dysfunction with either of these neurotransmitters or in any one of the brain areas in the system, which helps explain how one disorder can have so many different faces. For instance, the locus coeruleus serves as the on-off switch for sleep and thus is closely tied to circadian rhythms. One of the common symptoms in people with ADHD is abnormal sleep patterns: they often have problems going to sleep or staying asleep, and they suffer sleep disturbances such as sleepwalking or sleeptalking and nightmares. Early theories about hyperactivity proposed that arousal was the chief problem, that children “bouncing off the walls” were essentially trying to keep themselves alert. But the locus coeruleus, which busily produces norepinephrine in the depths of the brain stem, is merely the first opportunity for error. Norepinephrine-carrying axons extending from there, along with dopamine-equipped axons from the ventral tegmental area (VTA), plug into neurons in the amygdala.

As I mentioned in chapter 3, the amygdala is responsible for assigning emotional intensity to incoming stimuli before we’re conscious of it, and then sends it along for higher processing. In the context of ADHD, the amygdala determines the “noticeableness” of things. An unregulated amygdala is what feeds the tantrums or blind aggression in patients with ADHD, and their oversensitivity to excitement can lead to panic attacks. Sometimes excitability is a positive — people with ADHD can get so enthusiastic about something that they energize a roomful of people. (Holding the attention of others is no problem for those with ADHD.)

Dopamine also carries signals to the nucleus accumbens, or reward center, which is where Ritalin, amphetamine-dextroamphetamine (Adderall), and the active agents of other stimulants — from coffee to chocolate to cocaine — end up. The reward center needs to be sufficiently activated before it will carry out its important duty of telling the prefrontal cortex that something is worth paying attention to. It engages the prioritizing aspect of executive function, and this is a central component of motivation. Essentially, the brain won’t do much unless the reward center is responsive. Laboratory studies have shown that monkeys with lesions in the nucleus accumbens cannot sustain attention and thus can’t muster the motivation to perform tasks that don’t carry immediate rewards. The same is true of people with ADHD, who favor immediate gratification over more mundane tasks that will help them down the road, like studying for a test that will help them get into college. I call them prisoners of the present. They can’t maintain focus on a long-term goal, and so it seems as though they lack drive.

The prefrontal cortex bears responsibility for ADHD too. We can think of inattention in general as an inability to inhibit interest in unimportant stimuli and motor impulses. In other words, we can’t stop paying attention to what we shouldn’t be paying attention to. The prefrontal cortex is also the home of working memory, which sustains attention during a delay for a reward, and holds multiple issues in the mind at once. If working memory is impaired, we can’t stay on task or work toward a long-term goal because we can’t keep an idea in mind long enough to operate on it or to ponder, process, sequence, plan, rehearse, and evaluate consequences. Working memory, which is like our random-access memory (RAM), can be considered the backbone of all the executive functions. A failure of working memory is also why people with ADHD are terrible at keeping track of time and thus prone to procrastination. They literally forget to worry about the passing time, so they never get started on the task at hand. An ADHD sufferer who is on the verge of losing her job because she’s always late to work might go for the cereal box in the morning, decide the cupboard needs to be rearranged, and forget that she has to be out the door at a certain time. Then, when she remembers, panic sets in.

ATTENTION, ALL CONTROL UNITS

It’s not simply a matter of whether the signals get through to capture our attention, but how fluidly that information travels. This is where the attention system ties in with movement and thus exercise: the areas of the brain that control physical movement also coordinate the flow of information.

The cerebellum is a primitive part of the brain that for decades was assumed to be involved only with governing and refining movement. When we learn how to do something physical, whether it’s a karate kick or snapping our fingers, the cerebellum is hard at work. The cerebellum takes up just 10 percent of the brain’s volume, but it contains half of our neurons, which means it’s a densely packed area constantly buzzing with activity. But it keeps rhythm for more than just motor movements: it regulates certain brain systems so they run smoothly, updating and managing the flow of information to keep it moving seamlessly. In patients with ADHD, parts of the cerebellum are smaller in volume and don’t function properly, so it makes sense that this could cause disjointed attention.

The cerebellum sends information to the prefrontal and motor cortices — the centers for thinking and movement — but along the route is an important cluster of nerve cells called the basal ganglia, which acts as a sort of automatic transmission, subconsciously shifting attentional resources as the cortex demands. It’s modulated by dopamine signals stemming from the substantia nigra. Dopamine works like transmission fluid: if there’s not enough, as is the case in people with ADHD, attention can’t easily be shifted or can only be shifted all the way into high gear.

A lot of what scientists know about the basal ganglia comes from research into Parkinson’s disease, which is caused by a depletion of dopamine in this area. The disease wreaks havoc with a patient’s ability to coordinate not only motor movements but also complex cognitive tasks. In the early stages of Parkinson’s, these malfunctions show up as adult-onset ADHD.

The parallel is important because, based on a number of strong studies, neurologists are now recommending daily exercise in the early stages of Parkinson’s disease to stave off symptoms. Scientists induced Parkinson’s in rats by killing the dopamine cells in their basal ganglia, and then forced half of them to run on a treadmill twice a day in the ten days following the “onset” of the disease. Incredibly, the runners’ dopamine levels stayed within normal ranges and their motor skills didn’t deteriorate. In one study on people with Parkinson’s, intensive activity improved motor ability as well as mood, and the positive effects lasted for at least six weeks after they stopped exercising.

What I find so compelling is the strong relationship between movement and attention. They share overlapping pathways, which is probably why activities like martial arts work well for ADHD kids — they have to pay attention while learning new movements, which engages and trains both systems.

A controversial treatment for dyslexia — which occurs in about 30 percent of ADHD patients — relies entirely on physical movements to train the cerebellum. Dyslexia, dyspraxia, and attention treatment (DDAT) is based on the theory that a disruption in the brain’s ability to coordinate movement might be responsible for eye-tracking problems and thus difficulties in learning to read and write. Researchers also know that most children with dyslexia perform worse than average on tests of cerebellar function. DDAT involves practicing a collection of fairly simple motor-skills drills twice a day for ten minutes. In 2003 British researchers tested the effectiveness of DDAT on thirty-five children with dyslexia and declared the results “astounding.” Compared to no treatment, the students who followed the DDAT regimen for six months showed a significant improvement in reading and writing fluency, eye movement, cognitive skills, and physical measures such as dexterity and balance.

My friend and colleague Ned Hallowell uses this method (among many others) at his ADHD treatment center and has seen the positive effects in his own son. And prominent scientists at Columbia University College of Physicians and Surgeons are just embarking on a large study assessing the usefulness of the DDAT method as a treatment for ADHD.

Pharmacological studies have shown that ADHD drugs help normalize the activity of the cerebellum, as well as the corpus striatum, so it’s clear these areas are important to attention as well as movement. Perhaps by training our brain’s movement centers to improve its higher functions, we can bring about a day when we’re not as dependent on medication.

EARLY CLUES

I have never gotten my taxes in before October. Every year begins the same way, with me resolving to beat the taxman’s deadline. In early January I neatly gather all my documents for my accountant. Then, inevitably, I’ll find that a monthly statement has gone missing. I need to call my credit card company for a copy, which seems simple enough, but it kills my enthusiasm. The detail of tracking down the missing document, or buying those little white tabs for labeling files, will gnaw at the back of my mind for months. But the momentum is gone and along with it my motivation.

As a child, thankfully, I had strict nuns for taskmasters, and when I wasn’t at school I was outside running full tilt in one sport or another. Still, my room was a disaster; I forgot things constantly; and my tennis coach claimed that I was the most consistently inconsistent player he’d ever seen.

I have ADHD, obviously, but I never knew it; the term didn’t exist when I was a kid. To the extent that anyone bothered with attention deficit, it was called hyperactivity.

As a doctor, I didn’t come across the disorder until I was teaching at Massachusetts Mental Health Center in the early 1980s. My residents presented a twenty-two-year-old patient who had been in and out of the hospital for bouts of violent behavior. He mentioned that he had been on Ritalin as a hyperactive teenager but had long since been taken off the medicine. It was believed that kids simply grew out of their hyperactivity after adolescence and that it was dangerous to keep them on stimulants into adulthood, for fear they’d become addicted. I suggested we try the Ritalin again, and it really toned down his violent outbursts. He was so relieved; he said he’d forgotten that he could feel calm and focused.

Around the same time, I was immersed in studying severe aggression — researching, treating, and writing about what made patients of all sorts so violent. I stumbled across a study by Frank Elliott, then chairman of the neurology department at the University of Pennsylvania. Within a large population of prisoners, he discovered that more than 80 percent of them had had serious learning problems as children.

I started to dig into the school histories of my aggression patients, and common stories emerged. It was clear that they shared a lifelong difficulty inhibiting their thoughts, behavior, and actions. Many of them hated authority, had low self-esteem borne of chronic failure, and were driven by impulse. They acquainted themselves with trouble early in life and never managed to tap into the positive aspects of their personalities. A lot of them had gotten addicted to drugs as teenagers. These tendencies could easily combine with a hair-trigger response to frustration and set off violent episodes. It started to click that such destructive behavior might be rooted in the attention system.

I began looking at my outpatients through the lens of attention. What I saw was that some people with chronic problems such as depression, anxiety, substance abuse, and anger also seemed to share an underlying condition of the attention system, which was easy to miss when it wasn’t wrapped in hyperactivity. I began treating them with ADHD medicine, and I saw great improvement. As I discussed my ideas with colleagues, it became clear that there were milder forms of attention deficit that didn’t necessarily land someone in prison or the hospital or the unemployment line. Once we looked past the stigma, my friend Ned and I recognized the symptoms in ourselves.

The first paper I wrote on adult ADHD was soundly rejected, based on the criticism that I must be misdiagnosing some form of underlying depression or anxiety or that I was trying to introduce a new disorder. But I knew we were onto something in 1989 when Ned and I gave our first lecture on the subject, at a small conference in Cambridge, Massachusetts, for an organization founded by parents of kids with ADHD. The title of our talk was simply “Adults with ADD” (we didn’t call it ADHD back then). After our presentation to a roomful of two hundred people, we figured we’d stick around for fifteen minutes or so fielding questions. We were there for four hours. Clustered around the microphone in the aisle, one person after another told bits of their personal stories and asked what they meant. Many of them had the same disorder as their children, and they knew it.

So did a fellow psychiatry professor who came in for treatment after overhearing me at a party one night discuss a case study. “I think you described me,” he said, and launched into a highly intellectual rendition of his own history. Charles, I’ll call him, was the classic absentminded professor, wearing glasses and unkempt tweed, and he knew a lot more about psychiatry than I did at that point — I’d read several of his books!

The twist to Charles’s story is that he had been a marathon runner who had blown out his knee and become depressed when he was forced to set aside his passion. That’s also when he noticed the symptoms of what we would agree was ADHD. He explained that he would have a tantrum if his girlfriend interrupted his writing, or yank the phone out of the wall if it rang while he was trying to concentrate. He was slipping out of touch with his friends. He fit the profile, and we decided to put him on ADHD medication, which helped.

He was already on antidepressants when he first came to see me, but once he finished physical therapy and started training again, he dropped them because he felt so much better. As he closed in on his old fitness level, he became convinced that the ADHD medication was holding back his performance. Charles knew his mile times down to the second, and he was ten seconds slower than he used to be.

He decided to try a few days without the ADHD medication, and he found that as long as he was training, he could focus. Looking back on it, we recognized that his attention hadn’t hampered him before because he’d always been a serious runner. Without a steady diet of exercise during his injury, he’d been unable to control his attention the way he needed to. Clearly, exercise had a powerful effect, and that was big news to me.

FOCUS ON EXERCISE

Around the time Charles came in, I began to see a number of other intelligent, high-functioning professionals who had ADHD and were able to compensate for it. They didn’t fit the stereotype in the literature. Nobody had ever talked about successful adults with attention disorders until Ned and I included their case studies in Driven to Distraction. Several of these patients had discovered on their own that they could use exercise as a way of self-medicating to allow them to be more productive. I remember one in particular who is now managing a billion-dollar hedge fund: he takes a stimulant in the morning and plays squash every day at lunch, right about the time the medicine wears off.

Most people instinctively know that exercise burns off energy. And any teacher who has ever dealt with a hyperactive child will tell you that kids are much calmer after recess. Being calmer and more focused is one of the happy consequences of the Zero Hour program in Naperville that I discussed in chapter 1.

School is an excruciating environment for a child with ADHD, given the need to sit still, face forward, and listen intently to a teacher for the better part of an hour. It’s impossible for some, and it’s the reason for a lot of disruptive behavior among schoolchildren. I got a dramatic reminder of this about ten years ago on a trip to the San Carlos Apache Indian Reservation in Arizona. As part of the tribe’s effort to tackle its community’s health issues, I was invited to talk about ADHD to doctors, medical staff, parents, and teachers. ADHD is a huge but largely undiagnosed issue for the reservation kids because the incidence of the disorder among Apaches seems to be much higher than for the general population. As I outlined the symptoms and treatments to a group of middle school teachers one afternoon, several of them remarked that all of their kids had trouble sitting still. I asked about recess and was told that the kids have three a day. “If it rains, and they can’t go outside,” one teacher piped up, “we bus the kids home. Otherwise, we can’t handle them.”

Incredibly, there are few studies that provide good statistics on the prevalence of ADHD. One of the best comes from the Mayo Clinic. Researchers tracked all of the children born in Rochester, Minnesota, between 1976 and 1982, and followed up with those who stayed in the community until they were five years old. In all, this included 5,718 kids. The study reported that at age nineteen, at least 7.4 percent had ADHD, and suggested that the prevelance might be as high as 16 percent. Other studies suggest that approximately 40 percent of children with ADHD do “grow out” of it, and when it does persist into adulthood, symptoms of hyperactivity often subside. It’s no coincidence that the prefrontal cortex, which is responsible for inhibiting impulses, doesn’t develop fully until we’re in our early twenties. This is the biology of maturity.

ENGAGE THE BRAIN

Given the leading role of dopamine and norepinephrine in regulating the attention system, the broad scientific explanation for how exercise tempers ADHD is by increasing these neurotransmitters. And it does so immediately. With regular exercise, we can raise the baseline levels of dopamine and norepinephrine by spurring the growth of new receptors in certain brain areas.

In the brain stem, balancing norepinephrine in the arousal center also helps. “Chronic exercise improves the tone of the locus coeruleus,” says Amelia Russo-Neustadt, a neuroscientist and psychiatrist at California State University. The result is that we’re less prone to startle or to react out of proportion to any given situation. And we feel less irritable.

Similarly, I think of exercise as administering the transmission fluid for the basal ganglia, which, again, is responsible for the smooth shifting of the attention system. This area is a key binding site for Ritalin, and brain scans show it to be abnormal in children with ADHD. Exercise increases dopamine levels in the rat equivalent of this area by creating new dopamine receptors.

One group of researchers, including the University of Georgia’s Rodney Dishman, examined the effects of exercise in ADHD kids by using motor function tests that provide indirect measures of dopamine activity. The results threw Dishman for a loop because boys and girls responded differently. In boys, rigorous exercise improved their ability to stare straight ahead and stick out their tongue, for example, indicating better motor reflex inhibition, which is the missing ingredient in hyperactivity. Girls didn’t show this improvement, which may be because of the lower incidence of hyperactivity in girls. Boys and girls both improved by another measure related to the sensitivity of dopamine synapses, although boys fared better after maximal exercise and girls after submaximal exercise (65 percent to 75 percent of maximum heart rate, respectively).

An overactive cerebellum also contributes to fidgetiness in ADHD kids, and recent studies have shown that ADHD drugs that elevate dopamine and norepinephrine bring this area back in balance. Exercise also increases norepinephrine. And the more complex the exercise, the better. Rats don’t do judo, but scientists have looked at the neurochemical changes in their brains after periods of acrobatic exercise, the closest parallel to martial arts. Compared to rats running on a treadmill, their cohorts who practiced complex motor skills improved levels of brain-derived neurotrophic factor (BDNF) more dramatically, which suggests that growth is happening in the cerebellum.

In the limbic system, as I’ve explained, exercise helps regulate the amygdala, which in the context of ADHD blunts the hair-trigger responsiveness a lot of patients experience. It evens out the reaction to a new stimulus, so we don’t go overboard and scream at another driver in a fit of road rage, for example.

To the extent that ADHD is a lack of control — of impulses and attention — the performance of the prefrontal cortex is critical. The seminal 2006 study from Arthur Kramer of the University of Illinois used MRI scans to show that walking as few as three days a week for six months increased the volume of the prefrontal cortex in older adults. And when he tested aspects of their executive function, they showed improvement in working memory, smoothly switching between tasks and screening out irrelevant stimuli. Kramer wasn’t on the trail of ADHD, but his findings illustrate another way exercise might help.

Everyone agrees that exercise boosts levels of dopamine and norepinephrine. And one of the intracellular effects of these neurotransmitters, according to Yale University neurobiologist Amy Arnsten, is an improvement in the prefrontal cortex’s signal-to-noise ratio. She has found that norepinephrine boosts the signal quality of synaptic transmission, while dopamine decreases the noise, or static of undirected neuron chatter, by preventing the receiving cell from processing irrelevant signals.

Arnsten also suggests that levels of the attention neurotransmitters follow an upside-down U pattern, meaning that increasing them helps to a point, after which there’s a negative effect. As with every other part of the brain, the neurological soup needs to be at optimum levels. Exercise is the best recipe.

A CLASSIC CASE

If you were to run into Jackson, my former patient, you would meet a compact twenty-one-year-old in jeans and an untucked shirt who speaks articulately about his plans for the future — a typical American college kid, if not a little smarter. What stands out about him isn’t so much where he is today but how far he has come to get here and how he did it. Jackson runs nearly every day, three miles on days that he also lifts weights, six miles on the others. “If I don’t do it, it’s not like I feel guilty,” he says. “It’s that I feel like I’ve missed something in my day, and I want to go do it. Because I figured out that while I’m exercising I don’t have trouble concentrating on anything.”

Jackson was fifteen when he first came to see me, for anxiety exacerbated by his ADHD. His tendency to procrastinate invariably put him in impossible situations, and though he prided himself on the craftiness with which he manipulated teachers and academic deadlines, the constant conning took a toll on his nerves. By the end of high school, he had dug himself into a hole so deep that even he wasn’t sure he could hustle his way out of it. His future came down to one question on one math test that he postponed until just before graduation. “I dragged it out for so many days that I didn’t actually know if I was going to graduate,” he recalls. “I was out there in a cap and a gown and didn’t know if they were going to say my name.” He pauses, and then adds, “I felt dumb.”

Jackson was diagnosed with ADHD early on, after his third grade teacher picked up on his disruptive behavior and inability to complete class work. He began taking Ritalin and stayed on some form of stimulant throughout his school years. He was smart, but he had a lot of trouble with school. As a day student at a top-ranked private academy, he simply had more work than he could get through. Sleep became rare, and when it did come he would often wake up with a stomachache, dreading the drive to school. After having a panic attack, he withdrew from the school — despite a B average earned primarily by acing tests — and transferred to a public high school. Unlike some ADHD kids, Jackson was very social, founding after-school clubs and serving as a peer counselor for troubled kids — he figured he had a pretty good handle on psychology after everything he’d learned through his own troubles.

All the extracurricular activity served as a foil for what was turning into severe anxiety and depression, and at one point I had him taking Adderall, paroxetine (Paxil), and clonazepam (Klonopin), a long-acting anxiety drug. Academically, the material was easy enough, but the homework was such a source of stress that either he didn’t do it or he rushed through it between classes. He had convinced himself that he was smart enough to pull off high school without really doing the work. He says he felt like a “secret agent man,” sneaking around, subverting the attendance rules, and dodging teachers to finish assignments and then feigning innocence. “I thought I was so cool,” he says. “My crowning achievement was in this history class that I actually really liked. I didn’t do this huge paper, but I managed somehow to trick the teacher into thinking I had — and that I got an A on it. I never handed it in.”

They did call Jackson’s name at graduation. He squeaked through with a 1.8 GPA, far too low to go to the college he hoped to attend, despite family connections. A small junior college accepted him, though, and that was just fine. The triumph of completing school along with the comfort of having a destination the next fall put him on top of the world. In fact, he felt so good that summer that he decided to go off his medication — all of it. (Needless to say, I was not in the loop at the time.) It was the first time since grade school that he’d gone unmedicated for more than a day or two. “I noticed that a lot of the small things that bothered me went away,” he reports. And some not-so-small things: for the first time in his life, he was able to stick to normal sleep patterns, and his anxiety subsided. He figured he was simply feeling great because he had made it through school, but then when he took some ADHD medicine to sit for an English placement exam for college, the irritating side effects returned. After the test, he shelved the meds.

The turning point, however, happened in Spain that summer on a trip with his girlfriend. Walking around shirtless on the beach with all the “Spanish dudes,” he was inspired to do something about his Buddha belly. “I just started to run,” he says. “And I started feeling great. Part of that, I’m sure, is that I was on vacation in Spain. Everything was great in my life, and I was going to this college that wasn’t that hard, so I’m like, Maybe I can just do this! I went to college that fall and I never struggled for a second.”

Jackson’s story appeals to me partly because he got into exercise for his body image but stuck with it for the therapeutic effect. At first, all the running didn’t make a dent in his physique (thanks to pizza and beer), but he stuck with it because it helped him focus. In his first semester at the junior college, he earned a 3.9 GPA, and after a year he was accepted as a transfer student at the college he had originally wanted to attend. It’s a small, competitive New England institution, where he earned a 3.5 GPA as a sophomore. His major? Psychology.

He’s clearly tuned in to his own state of mind. If he falls off his exercise regimen, his concentration wavers. “I can definitely tell when I don’t do it,” he says. “It got to the point during midterms that I had no time, but I’m like, You know what? I have to go out and run and clear my head. I have to do this.”

He knows how it makes him feel, and that knowledge itself keeps him going.

“I always have a million voices in my head all the time,” he explains. “When I started exercising, it wasn’t that I was just thinking about one thing — because I also have a problem hyperfocusing — but it was like I could concentrate on things that were important to me. Then I started thinking about it, and in general now I really don’t have trouble concentrating. And because I’m off the meds, I don’t have nearly as many sleep problems. There’s never been any question in my mind that exercise is related, because it’s this huge life change that I made. It’s just so clear.”

TAKE THE INITIATIVE

Not everyone with ADHD will experience the sweeping effect of exercise that Jackson did. And I would never have suggested he abruptly quit taking his medication, especially the antidepressant. His experience begs the question of whether exercise can replace Ritalin or Adderall or bupropion (Wellbutrin), and for the vast majority of cases I would say the answer is no. At least not in the way James Blumenthal and his colleagues at Duke showed that exercise can stand in for Zoloft in treating depression.

Yet there is something instructive in Jackson’s motivation for discontinuing his medication. I think he felt out of control, knowing that he was smart enough to succeed but unable to make it happen. Constant frustration can lead to feelings of demoralization, and in Jackson’s case, this fed his depression and anxiety. For him, taking medication exacerbated that feeling, creating a sense of dependency. Conversely, getting into a running routine provided a sense of control over his inner self — his mood, his anxiety, his focus. For the first time in his life, he felt like he could steer his own future. He used running as his medicine.

For most of my patients, I suggest exercise as a tool to help them manage their symptoms along with their medication. The best strategy is to exercise in the morning, and then take the medication about an hour later, which is generally when the immediate focusing effects of exercise begin to wear off. For a number of patients, I find that if they exercise daily, they need a lower dose of stimulant.

I’m talking about taking the lead in your own treatment: the more you know about how ADHD works, and the more you recognize your foibles, the better you can prepare for them. I tell my patients they need to develop militant vigilance in terms of scheduling and structure. If you set up your environment in a certain way, you can corral your attention through your own actions and become more productive. Arrange your day and your surroundings in a way that encourages focus and accomplishment — moving the ball forward rather than letting it ricochet off the walls. I’m not suggesting that getting organized and establishing structure can melt away symptoms, but it can funnel your attention in the right direction. Today many people are using ADHD coaches to help them do this. The external accountability is a powerful way to help you maintain routines such as exercise and to meet your goals.

Jackson establishes structure for himself with his daily runs, and this works on two levels: the regular schedule shapes his time so he doesn’t have to think about it, and the exercise itself focuses the brain in all the ways I’ve mentioned.

It’s true that many ADHD kids are more active than their peers — studies show they have less body fat, on average — and I see plenty of adults with ADHD who are already exercising. But they need to be doing more, and on a regular basis. In general, I tell my patients to make every effort to institute a regimen of daily exercise — or at least during the five weekdays, when they need to focus at school or work. Dishman’s study suggests that submaximal exercise, which would be 65 to 75 percent of maximum heart rate, is more effective with girls, while more vigorous exercise (just below the anaerobic threshold, which I’ll explain in chapter 10) works better for boys. We don’t really have parallel data for adults, but from what I’ve seen, it’s important to get the heart rate up there — maybe 75 percent of your maximum for twenty or thirty minutes.

For ADHD in particular, the complex, focus-intensive sports such as martial arts and gymnastics are a great way to tax the brain. By engaging every element of the attention system, it holds you rapt. These sports are just more interesting than running on a treadmill, and participation tends to be self-perpetuating — it’s easier to stick with it.

I try to do my workout first thing in the morning, both for the structure it affords and to set the right tone for the day. A lot of times, that keeps me going. And once I get into the intensity of therapy sessions, it’s easy for me to hyperfocus on each patient. Researchers haven’t quantified how long the spike in dopamine and norepinephrine lasts after exercise, but anecdotal evidence suggests an hour or maybe ninety minutes of calm and clarity. I tell people who need medication to take it at the point when the effects of exercise are wearing off, to get the most benefit from both approaches.

The truth is, everyone has a different level of attention deficit, and you’ll have to experiment to see what regimen works. My hope is that knowing how it works will allow you to find the best solution for you. If you want a minimum, I would say thirty minutes of aerobic exercise. It’s not a lot of time, especially considering that it will help you focus enough to make the most of the rest of your day.