Attention Deficit Hyperactivity Disorder (ADHD) has long been a target of those who dislike the very concept of mental disorders. This is partly because the emotional stakes are high – the diagnosis often results in children being treated with stimulants. Opposition to the concept of ADHD also reflects fundamental misunderstandings about medicine.

A recent opinion piece in The Blaze by Matt Walsh reflects this deep misunderstanding and unease with the concept of mental illness.

Throughout the piece he uses the terms “disease” and “disorder” interchangeably, without defining either. The distinction is important, because it relates to how medicine defines diagnostic entities. Not all diagnoses are created equal. I spend a great deal of time teaching medical students to have a sophisticated and nuanced understanding of the labels they will be attaching to their patients.

As with every branch of science, labels are used as placeholders of our understanding of phenomena, and also as a necessary contrivance to allow technical communication among experts, in the scientific literature, and also to the public. In medicine we need labels for certain practical applications, such as documentation, epidemiology, drug indications, reimbursement, and research. Labels are a scientific tool, and they need to be understood to be used properly.

ADHD is certainly not a “disease.” The term disease should be reserved for entities that involve a discrete pathophysiological condition. Type II diabetes is a disease – it is defined by specific physiological conditions.

In medicine, however, there are also clinical syndromes, disorders, and categories of disorders. This is because we don’t understand everything about every medical condition. Further, we are trying to describe 7 billion people, who display tremendous variability – it’s a variable and chaotic system.

What typically happens, therefore, is that new entities are first described clinically. They are recognized and defined as a cluster of signs and symptoms and perhaps a natural history that tend to occur together, meaning that more than one patient will display the same constellation of findings, suggesting a common underlying process. This does not necessarily mean that the underlying pathology or ultimate cause is the same, however. The clinical syndrome may just represent the final common pathway of multiple processes.

We talk, for example, about heart failure as a clinical syndrome, even though many underlying pathologies may cause the heart failure.

Over time, as our understanding improves, there is a tendency to shift from clinical syndromes to more pathophysiological diagnoses. Sometimes this requires a change in the labels and categories, sometimes it doesn’t. The muscular dystrophies started out their medical life as clinical syndromes. It was decades later that the underlying genetic mutations that cause these disorders were identified and understood. Some muscular dystrophy diagnoses survived this change, others did not.

In the area of mental conditions, we are largely still in the era of clinically defined syndromes. We are starting to understand the underlying neurological causes of some of the more discrete disorders, such as schizophrenia, and this is also started to change our classification system.

However, brain disorders are different than other organ systems in that function relies upon more than just the biological health of the cells and tissue. Liver disease is largely caused by pathological processes affecting liver cells. There is also brain disease caused by pathological processes affecting brain cells. However, brain cells also have other layers of complexity to their function, the pattern of connections and the biochemical processes that underlie brain processing. Therefore there can potentially be a brain disorder without underlying classical pathology – with healthy brain cells but that happen to be connected in a dysfunctional pattern.

To add another layer of complexity, part of the function of the brain is to interact with the environment, including other people and society.

Because of this, medicine uses the concept of mental disorder to define a clinical entity in which a cluster of signs and symptoms relating to thought, mood, and/or behavior causes demonstrable harm. This is a reasonable and practical definition. But it is a clinical placeholder, and should not be confused with a discrete pathophysiological entity. That does not mean it’s not a real disorder, or that any specific intervention to mitigate the harm is not useful or appropriate.

Walsh describes his own symptoms this way:

Even now, I daydream all the time. I can’t sit still. I can’t concentrate on mundane tasks. I get lost in my own head. I forget things. I can’t stay on one train of thought for very long. At this very moment, I have four different word documents open on my computer and I am working on four different posts at the same time. Three of them will never be published or completed. Ask my wife, she’ll tell you all about it.

Walsh prefers to think that this is part of the normal variation of human behavior, and the only reason it is defined as a disorder is because it causes inconvenience to others. The latter part of the claim is not fair. Many people who are diagnosed with ADHD find it an inconvenience to themselves and want help.

ADHD is understood as a disorder of executive function, which is a definable neurological function that localizes to the frontal lobes. Executive function is what enables us to pay attention, to plan our behaviors for strategic benefit, and to inhibit behaviors that are not socially appropriate or in our own best interests. Like every human trait, executive function varies from person to person. Even in the “normal” population (meaning without specific injury or disease) there will be those at the low end of the Bell curve. The same is true for music ability, math ability, reading ability – pretty much any neurological function. Decreased executive function can also be acquired by injury or a pathological process.

Low executive function is considered a disorder, while low musical aptitude is not, because the former is associated with demonstrable harm while the latter is not. Those with low executive function tend to have difficulty in school or any structured and restrictive setting, they have higher divorce rates, higher incarceration rates, lower lifetime income potential, and are at higher risk of depression. Often they are frustrated by their inability to adapt to the demands of school or work.

Further, evidence clearly shows that medication for ADHD improves function and outcomes and is cost effective. Behavior interventions also have an effect, but it is smaller and less certain.

In short, the scientific evidence clearly points to the conclusion that ADHD is a real neurological disorder characterized by hypofunctioning of executive function with demonstrable negative outcomes. Further, these outcomes can be improved with treatment. Walsh and others, however, try to deny this basic scientific reality with logical fallacies and misdirection.

One strategy Walsh employs, which is typical of denialism, is to cherry pick outlying experts, rather than reflect the consensus of expert opinion. He also misrepresents some of those experts. For example, he links to this article by Dr. Richard Saul. Sure, the headline says: Doctor: ADHD Does Not Exist. This might lead someone who did not read and understand the article to the wrong conclusion. Saul writes:

However, there are some instances in which attention symptoms are severe enough that patients truly need help. Over the course of my career, I have found more than 20 conditions that can lead to symptoms of ADHD, each of which requires its own approach to treatment.

He is not saying that the syndrome of ADHD does not exist, or does not need to be treated. What he is saying is that ADHD is not a primary disorder, but rather a secondary symptom of a number of different underlying disorders. Those underlying disorders need to be indentified and treated specifically. While I agree with him that ADHD is sometimes a secondary symptom, I don’t think you can scientifically justify the conclusion that there is no primary ADHD disorder. He is correct, however, in that lazy or insufficiently trained clinicians might use ADHD as a catchall diagnosis and fail to look for underlying problems. This is a generic problem of quality control in clinical medicine, and we see this in every field.

Walsh then plays the, “behaviors cannot be a disease,” card:

There are many reasons to view ADHD as a fraud, but let’s start with the fact that at the very beginning, before you take one step into the issue, it already makes no sense. Impulsive? Impatient? These are personality traits, not medical conditions. Daydream? Talk a lot? Interrupt? These are behaviors, not symptoms of a disease.

Since behaviors emerge from the functioning of the brain, and the brain can be disordered, then behaviors can be symptoms of a brain disorder. This is where he uses definitions, like “disease”, in a slippery way to cause confusion.

He goes on to argue that these behaviors are normal in children. The obvious response is that the disorder, as with most mental disorders, is a matter of degree, to which he responds:

Now you might say, well yes, they’re normal, but some kids, like, talk A LOT, and daydream A LOT, and interrupt A LOT. To that I’d respond: yeah, still pretty normal.

The question is – is there any degree of behavior that can meaningfully be described as a disorder? Walsh is implying that no matter how impulsive, distracted, and disruptive a child is, it must be consider part of the normal spectrum. Part of the problem is that “normal” is not a useful technical term, because it doesn’t have a good operational definition. Walsh can call anything normal – it all occurs as part of the human condition. Any gene variant is just as valid as any other gene variant. Who’s to say which is “normal.”

“Disorder,” however, does have an operational definition – it must be the lack of a trait or ability that most people possess that is linked to demonstrable harm. This is independent of any judgement about whether or not the condition is “normal.”

Even Walsh has to admit that some children are really far off the mean of the Bell curve, so he employs a little distraction:

But maybe you have kids who do these things A LOT A LOT. Beyond the normal a lot, and into the realm of REALLY A LOT. Alright, fine. So where’s the cut off?

This is a non sequitur. Sure, it’s a continuum, just like height. There is no dividing line between short and tall, but Kareem Abdul Jabbar is freaking tall. Further, we draw dividing lines to separate continuums of biological functioning in order to define diseases and disorders all the time. High blood pressure is defined as 160/90. Does that mean that 159/89 is perfectly healthy? Of course not, but we need to draw a line somewhere. This is the “false continuum” logical fallacy -denying the existence of the extreme ends of a continuum because there is no sharp dividing line.

This raises another one of my criticisms of mental illness denial – it uses features that are generic to all of medicine and pretends that they are unique to psychiatry. He is doing this when he writes:

Let’s look at an Actual Sickness for comparison. Let’s look at dementia. There’s an honest-to-God mental disease. It’s also a disease that can be physically observed in the human body. You can see it quite unmistakably in a brain scan. And there are clear symptoms, like hallucinations. Notice, there isn’t a spectrum where acceptable hallucinations graduate into unacceptable hallucinations. Hallucinations are always bad, to any degree whatsoever.

Walsh here is completely wrong on every point. First, you cannot always see dementia on a brain scan. Dementia is a category of diseases, it is not one disease. Some do not have specific brain scan findings. The early stages of most will not be evident on brain scan. Dementia is defined clinically, by a cluster of signs and symptoms. We then have to look for underlying causes, and may or may not find one. Further, there is no clear demarcation between normal aging and early dementia. There is a diagnosis called minimal cognitive impairment, which defines those who have symptoms of mild dementia but may not have dementia.

His example of hallucinations is also highly problematic. First, that is not a classic symptom of dementia. It’s a symptom of psychosis. Also, it is not always pathological as he says. Hallucinations sometimes are “acceptable.” For example, a percentage of the healthy population have hypnagogic hallucinations – associated with transition from sleep to wakefullness. These are hallucinations, but they are benign, not part of any disease or disorder. They can also be a symptom of a sleep disorder. And hallucinations generally can be symptoms of many things, from drug side effects to schizophrenia. Symptoms often have to be put into context.

This really was a terrible example for Walsh to use to make his point, but makes my point perfectly. Walsh simply does not understand the nature of diseases and disorders and how they are defined.

The rest of his article essentially repeats the same fallacies – false continuum, appeal to cherry picked outliers, misunderstanding the nature of medical diagnoses, and flat out denial and mischaracterization of the science. He also adds the argument that it’s all good:

I told you about my “ADHD.” Well, a funny thing happened. The precise disposition that made it very difficult for me to excel in chemistry class or while working as a cashier is now the precise disposition that makes it possible for me to excel in my current career. Writing, debating, creating new ideas, trying to earn a living in the ever changing world of new media — I couldn’t do any of that if I wasn’t like this. What made me a failure in school makes me extremely successful in this realm. How do you explain that?

He has a kernel of a point here – human behavior is complex and we always need to strive for a sophisticated and nuanced understanding of the interaction of brain function with society and culture. Overly simplistic approaches can be counterproductive, and with behavior there are often tradeoffs. If your ADHD is working for you, then don’t treat it. No one is going to strap you down and give you stimulants.

The situation is more complex for children, and we do need to be their advocates. Some children are truly struggling, are frustrated and unhappy because of the challenges presented by their ADHD (even if it might have advantages in other contexts). Researchers are looking for ways to mitigate the negative effects of ADHD with behavioral methods, parenting methods, and individualized approaches as school. These have some benefit, but often not enough. Walsh has not presented a coherent argument for why medication should not be used in such cases, even though the evidence shows it is safe and effective.

Conclusion

There is a clear consensus based upon robust scientific evidence accumulated over decades that ADHD is a real disorder. Denying the reality of ADHD, in my opinion, is just like any other science denial, and employs the same suite of methods and fallacies in order to do so.

At the core of mental illness denial is a fundamental misunderstanding of medicine in general. False dichotomies are drawn between mental health and the rest of medicine, and the examples used to make those dichotomies are always fatally flawed.

I also find that mental illness denial has many potential negative consequences. It further stigmatizes mental illness, which should be viewed as just another biological function without any social stigma. Walsh, in his denial, is also quick to blame ADHD on parents for not properly raising their children. This is both untrue and counterproductive.

Ironically it is the stigma that often motivates the denial of mental illness. The solution is not to deny mental illness, but to recognize that the brain is just another organ and should provoke no more of a social stigma than liver disease.