Are Mental Illnesses Really Brain Diseases?

Dr Eric Kandel

Dr Eric Kandel

In an article titled “The Roots of Mental Illness,” the author, Kirsten Weir, tells us about Eric Kandel, MD, who believes that the experiences that doctors refer to as mental illnesses are brain diseases. Dr. Kandel defends his belief with the following statement: “All mental processes are brain processes, and therefore all disorders of mental functioning are biological diseases. The brain is the organ of the mind.”

The article also indicates that Dr. Kandel believes one important value of recognizing that these types of experiences are brain diseases is that it helps minimize the shame often associated with them. For example, Dr. Kandel is quoted as saying, “Schizophrenia is a disease like pneumonia. Seeing it as a brain disorder destigmatizes it immediately.”

kandel-nobel-prizeDr. Kandel’s credentials are pretty impressive–he’s a Nobel Prize laureate and professor of brain science at Columbia University. Therefore, if you are among those who believe a person’s credentials should determine who is right and who is wrong, you need not read any further. You must simply conclude that what is referred to as mental illnesses are indeed brain diseases because you would be hard pressed to find someone with better credentials disagreeing with Dr. Kandel.

However, if you are among those of us who believe that regardless of someone’s credentials, the reasonableness of the argument should sway your judgments, then I encourage you to read on. In brief, you will find that the phrase, “disorders of mental functioning” is way too vague for a science of disease, and that Dr. Kandel’s conclusion that seeing these types of experiences as brain diseases immediately destigmatizes it, is at the very least, questionable.

Are Disorders of Mental Functioning Properly Viewed as Brain Diseases?

Colony of pathogen bacterias - 3d render

Colony of pathogen bacterias

Physical pathologists, who are trained in the principles of science, determine if a pathological condition is present by looking for a set of objectively observable body conditions such as tumors, microbe infections, tissue tears, bone fractures, and blocked arteries. None of these have been identified by pathologists as causing the conditions typically labelled by psychiatrists as mental illnesses. If they were to find the physical pathology that causes any of the behavior patterns referred to as mental illnesses, that pattern would no longer be referred to as a mental illness. Instead, the pattern would be viewed as the symptoms of the  physical pathology, and the disease would be referred to either as the type of pathology (tumor, microbe infection, etc.) or the name of the person who discovered the relationship between the behavior pattern and the physical pathology.

Dr. Kandel, when trying to make the case that mental illnesses are real brain diseases has, at times, cited articles that show some correlation of a brain difference with some of the concerns that lead to a mental illness label. But these correlations are far too weak to demonstrate they are causing these types of concerns. For example, people labeled as having schizophrenia have, on average, some larger brain ventricles. However, there are many people who have the same size ventricles, or even larger ones, who show no signs of schizophrenia. Moreover, numerous people who have smaller than average size ventricles are regularly classified as having schizophrenia. Thus, quite clearly, it is not the size of the ventricles that are causing the schizophrenic behavior pattern. It is for this reason that the size of one’s brain ventricles is not used to make the so called diagnosis of schizophrenia. Instead, doctors rely on a conversation with the designated patient to make these types of so called diagnoses.

Are such conversations properly viewed as objective criteria for determining a disease state and equivalent to observing the type of pathologies that physical pathologists look for in identifying a disease state? Numerous critics of psychiatry say no. They point to what highly credentialed doctors have, over the course of history, claimed are mental illnesses.

Dr Samuel Cartwright

Dr. Samuel Cartwright

For example, in 1851 American physician Samuel A. Cartwright labelled black slaves who tried to flee captivity as having the mental illness of drapetomania. For people who hold the value judgment that the function of healthy blacks is to be slaves, then it certainly makes sense to say that blacks seeking to flee captivity were being dysfunctional.

Freud Practicing the Dysfunctional Habit of Smoking

Freud Practicing the Dysfunctional Habit of Smoking

If you are religious, many highly credentialed medical doctors, including Sigmund Freud, who, like Dr. Kandel, won a Nobel Prize, have claimed this meant you had a mental illness. People who are gay were declared as having a mental disease here in the US. In the former Soviet Union, if you were opposed to communism it warranted a mental illness label by their psychiatrists. In each of these societies, a case was made that the behavior pattern labelled as a mental illness was dysfunctional.

New-quote-from-William-JamesThe argument that such labeling practices are not scientific, but, rather, value judgments, was intelligently made by William James when he defended the religious sentiment. He explained that pathologizing these sentiments as mental diseases was superficial medical talk. He called the reasoning doctors used to declare religious beliefs a type of mental illness, “medical materialism.”

Medical materialism seems indeed a good appellation for the too simple-minded system of thought which we are considering. Medical materialism finishes up Saint Paul by calling his vision on the road to Damascus a discharging lesion of the occipital cortex, he being an epileptic.

Woman of Religious Faith

Woman of Religious Faith

It snuffs out Saint Teresa as an hysteric, Saint Francis of Assisi as an hereditary degenerate. George Fox’s discontent with the shams of his age, and his pining for spiritual veracity, it treats as a symptom of a disordered colon. Carlyle’s organ-tones of misery it accounts for by a gastro-duodenal catarrh. All such mental overtensions, it says, are, when you come to the bottom of the matter, mere affairs of diathesis (auto-intoxications most probably), due to the perverted action of various glands which physiology will yet discover.

James goes on from here to point out that it is true, of course, that psychology has found that there are definite psychophysical connections that “hold good.” Psychology, therefore:

brain-disease-3assumes as a convenient hypothesis that the dependence of mental states on bodily conditions must be thoroughgoing and complete. If we adopt the assumption, then of course what medical materialism insists on must be true in a general way, if not every detail…. But now, I ask you, how can such an existential account of facts of mental history decide in one way or another on their spiritual significance? According to the general postulate of psychology just referred to, there is not a single one of our states of mind, high or low, healthy or morbid, that has not some organic process as its condition. Scientific theories are organically conditioned just as much as religious emotions are; and if we only knew the facts intimately enough, we should doubtless see “the liver” determining the dicta of the sturdy atheist as decisively as it does those of the Methodist under conviction anxious about his soul. When it alters one way the blood that percolates it, we get the Methodist, when in another way, we get the atheist form of mind. So of all our raptures and our drynesses, our longings and pantings, our questions and beliefs. They are equally organically founded, be they religious or of non-religious content.

James points out that in the natural sciences it never occurs to anyone to refute opinions by putting down their authors’ neurological constitutions. Value is determined by “judgments based on our own immediate feelings primarily; and secondarily on what we can ascertain of their experiential relations to our moral needs and to the rest of what we hold as true.”

brain-diseaseAll states of mind are related in extremely complex ways to neural functions. There is a crucial distinction to be made between a brain difference and a brain pathology. The significance of each state of mind must be tested, not by some neurological difference, but by the value of its fruits. When the term “pathological” is applied to an experience, rather than an identified physiological pathology, it wrongly implies a neutral science classification.

In my view, what William James says about the religious sentiment and disease states hold just as true for people who are currently declared as having a mental illness by Dr. Kandel and many other doctors. They declare, in a very subjective manner, patterns of behavior are due to a brain disease without objective proof that there is a physical pathological condition causing the pattern. They don’t make a distinction between a brain difference and a brain disease. And they don’t deal effectively with the fact that there are numerous people who display patterns that have been viewed by the psychopathologizing doctors who have brought forth some of the greatest fruits known to the human race.

Calling Mental Illness a Brain Disease: Does It Stop Stigma?


In the above Aldous Huxley quote, apparently it was his opinion that all the normal people in our society are dysfunctional, and thus psychiatry might want to declare all normal people as having a brain disease. I wonder if all normal people might feel less stigmatized upon hearing about this pathologizing of their experiences. Hmmm.

Anyway, if you will, let us turn to Dr. Kandel’s declaration that by getting people to see that mental illnesses are brain diseases it destigmatizes them immediately. He offered no scientific evidence for this. When we actually look at the evidence bearing on his statement, we get a very different impression.

Lincoln, sufferer of depression

Lincoln, sufferer of depression

Very modest evidence exists indicating people who have become convinced that mental illnesses are brain diseases are somewhat less likely to blame labeled persons for their behavior. However, at the same time, overall stigma actually increases. Biological explanations, for many, imply that people with mental illness are fundamentally different or less human.

Research has also shown, that disease explanations for mental illness provoked harsher behavior toward labeled persons. It is worthwhile keeping in mind that in the not-so-distant past, biological and genetic explanations for stigmatized conditions were linked to a range of harsh policies, including marriage restrictions, sterilization, lobotomies, and even extermination.

Painter who has been said to suffer from mental illness

Painter who has been said to suffer from mental illness

The biological explanation may also exacerbate yet another key stereotype of mental illness, the belief that people with mental illness are dangerous. Many researchers believe that the stereotype that people with mental illness are violent ranks among the most prejudicial and discriminating of attitudes. Unfortunately, there is evidence that biological arguments may actually strengthen dangerousness stereotypes, suggesting that people with mental illness have no control over their behavior and therefore are unpredictable and violent.

brain-disease-5In contrast to biological arguments, psychosocial explanations of mental health concerns have been found to effectively improve images of people who are now being labeled as having a mental illness. It also appears to reduce fear.

Instead of arguing that mental illness is like any other medical illness, psychosocial explanations of mental health concerns focus on environmental stressors and trauma as causal factors. These may include childhood abuse, poverty, and job stress. The idea is to reframe mental health concerns as understandable reactions to life events.


Socrates heard voiced in his head and was condemned to death by society leaders.

Socrates heard voices in his head that he referred to as guiding demons and was condemned to death by society leaders.

The mental health concerns that most modern day doctors refer to as mental illnesses, have not been shown to be caused by a physiological pathological condition. There are undoubtedly some brain differences that have been correlated with a few types of concerns, but it is way too simplistic to say that such differences are the cause of any of these concerns. It is very possible that environmental and cultural factors may lead to the observed correlations. Despite the fact that a person might be said by some that he or she is functioning below average in some ways under some societal situation, numerous examples can be easily provided that people labeled mentally ill have often produced valued fruits in the fields of science, arts, and philosophy. Finally, labeling someone experiencing a mental health concern as having a brain disease does not automatically increase stigma, and could actually increase it.

Some people will enjoy reading this blog by beginning with the first post and then moving forward to the next more recent one; then to the next one; and so on. This permits readers to catch up on some ideas that were presented earlier and to move through all of the ideas in a systematic fashion to develop their emotional intelligence. To begin at the very first post you can click HERE.

The Pathologizing of Human Experience
Are Mental Illnesses Really Genetic Diseases?

About the Author

Jeffrey Rubin grew up in Brooklyn, received his PhD from the University of Minnesota and has taught conflict resolution there as well as at a psychiatric clinic, a correctional facility and a number of public schools. He has published articles on anger and conflict resolution and has authored three novels.


  1. No it’s not, it’s a development of nurture against nature, it’s like Aribics being discriminated when the first researcher of curing mental illnesses was a Persian man name Muhammad or rhazo in the 800s. It’s all based on chemical reactions mixed with behavior that is nurtured into our symbolic spectrum in the occipital lobe that allows comprehension in a “metaphorical” spectrum like quantum physics and the consciousness. As time is equal to space because as time comes space increases. Symbolically as consciousness (c) expands the thought(h) causes our frequency(f) to fry our brain. Which probably explains why the proteins in our brain turned hamburger grey.

    • Hi Austin Lee Grochowalski,
      I enjoyed reading your comment. Think it indicates that we are in agreement that referring to the concerns that get labelled as mental illnesses are not aptly construed as brain diseases. Your description of what these concerns are strikes me as a mixture of some factors that are involved and poetry.

  2. Regardless of opinion there is no way that a so-called “mental illness” can not be a disease of the brain – when in fact we look at it as the very (primary) mechanism that “mental” activity emerges from.

    So in fact, it cannot not be an issue or disease of the “brain” at all. ALL activity emerges from the brain and body and “mind” is a direct result of these two co-existing phenomena working in concert.

    Behavior is a direct result of mind-brain-body and therefore whatever we refer to as “mental illness” – which is a word that is becoming outdated to describe what we are dealing with – we might as well face it – is not what it is that is going on leading to the issues we are experiencing. It is something that involves the brain functioning as a system factor from a dominant and primary position consciously and preconsciously motivating and driving what we call “mind”.

    • Hi Eric,
      You appear to attribute all to the brain. But there is a universe operating in concert with the brain. The environments, along with our personal relations, and cultural history effect the brain which then goes beyond the information it takes in by performing operations upon this which then impacts the environment. It is not just the brain, we are part of an interaction process with others, in an incredible complex manner.

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