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The Meaning of Mental Illness

by Mark L. Ruffalo

"Men have all but incurable propensity to try to prejudge all the great questions which interest them by stamping their prejudices upon their language." – Sir James Fitzjames Stephen (1873)

What exactly is meant when a psychiatrist or mental health professional says that a person is mentally ill?  What is this concept called mental illness that seemingly pervades all aspects of society? I have found in my experience as a psychotherapist that the term "mental illness" is routinely used by persons both inside and outside of the field with little consideration paid to its conceptual or philosophical meaning. One has to look no further than the nighttime cable news programs, in which virtually everyone who commits a crime is said by one person or another to be suffering from a diagnosable mental illness. I believe that if we are to use words, we must be sure of their meaning. If we are to misuse words, we render them meaningless. When it comes to psychiatry and its core concept, mental illness, we must be sure to understand the significance of this idea before we begin to apply it to individuals.

When we ask ourselves What is mental illness?, it becomes evident that it is easier to define the concept in terms of what it is not than in terms of what it is. Mental illness is not disease, in the traditional medical sense of the term. Disease has always referred to objectively demonstrable alteration of cells, tissues, or organs, and mental disorders do not meet any of these criteria. This point is actually not controversial amongst mental health professionals with any real knowledge of psychiatric theory. Allen Frances, chair of the American Psychiatric Association's DSM-IV Task Force, writes in his 2013 book, Saving Normal, "Schizophrenia [for one example], is a useful construct, not myth, not disease" [emphasis added]. Even for a problem like schizophrenia—long considered the most severe mental illness—there exists no biological test to aid its diagnosis, and neuroimaging research has demonstrated no biological abnormality that is characteristic of the condition. Nonetheless, psychiatric patients are routinely told that they are suffering from diseases. "Depression is a disease just like cancer and diabetes," is a phrase muttered ad nauseum by psychiatrists and therapists daily, despite its patent falsity. I view this practice of telling psychiatric patients that they have a disease as not only misleading but also unethical.

What of the popular idea that mental illness is a "chemical imbalance of the brain"? As it turns out, this too is false, and the routine practice of telling psychiatric patients that they have a chemical imbalance is equally misleading and unethical, in my opinion. As Ronald Pies, a renowned professor of psychiatry, shared in 2011, "In the past 30 years, I don’t believe I have ever heard a knowledgeable, well-trained psychiatrist make such a preposterous claim [that mental illnesses are due to a chemical imbalance in the brain], except perhaps to mock it…. In truth, the 'chemical imbalance' notion was always a kind of urban legend—never a theory seriously propounded by well-informed psychiatrists." The only reason we believe that some mental disorders may be related to some chemical imbalance is because of the effect of psychiatric medications on these problems. In truth, we've never actually seen a chemical imbalance in the brain, and we really have no idea what one would actually look like.

If mental illnesses are not diseases and are not chemical imbalances of the brain, then what are they, and why is there so much popular focus on understanding the "biological basis" of mental illness? In simplest terms, mental disorders are variations of human behavior and experience that do not conform to established social norms. Biologically-oriented psychiatrists and psychologists are quick to point out that some mental disorders seem to be related to some biological changes in some cases. But such findings are meaningless in light of the fact that all human behaviors have some sort of neurological correlate and could be said to have a "biological basis." That some behaviors and experiences—socially defined as mental disorders—correlate with some changes in the brain really tells us nothing about the nature of the human problems called mental illnesses. Nor does it follow from the biological research that neuroscience is the most effective lens through which to view mental illness.

Mental illness is much more accurately defined as socially deviant behavior that is concerning or problematic for the person or those around him. It is, above all else, a method of relating to the world. As the psychiatrist-psychoanalyst Thomas Szasz (1961) first pointed out many years ago, "mental illness" is actually a metaphor, as "illness" is a synonym for "disease," and mental illness is not disease. This is not to say that mental illness does not cause suffering. There is, of course, great emotional pain and suffering in patients with mental illness. The fact that the human problems called mental disorders cause suffering has long been used to justify their classification as literal diseases, despite the fact that suffering has never been a sufficient criterion for medical disease. This is not to downplay or negate the very real existence of and problems caused by human emotional conflict, but rather to state the inconsistency of this claim.

Writers frequently refer to mental illness without realization of the metaphorical nature of this term. I have referred in my past writings to "mental illness" and persons being "mentally ill," but contextually it should be understood that these are metaphors and are not to be taken literally. It makes no sense and is, in fact, a logical and semantic error to insist that the mind can be sick in the same way that the body can be sick. To me, the metaphorical nature of mental illness is so plainly evident that it does not require explicit explanation. In his classic, Lectures on Clinical Psychiatry, Emil Kraepelin (1904)—the father of modern psychiatry—wrote: "The subject of the following course of lectures will be the Science of Psychiatry, which, as its name implies, is that of the treatment of mental disease. It is true that, in the strictest terms, we cannot speak of the mind as becoming diseased."

In my practice of existential psychoanalytic psychotherapy, I prefer to view mental illness in game-theoretical terms as a strategy created by the person to achieve some end. In this approach, the person is viewed as a free, moral agent; behavior is something that the person does, not something that happens to a person. The motivations and strategies may not always be readily known or acknowledged by the individual, thus much of psychotherapy entails making interpretations regarding the meaning of a person's conduct and his or her internal motivations and conflicts. The schizophrenic person can no longer entail the harsh reality of his experience, thus he creates his own reality. The depressed person becomes overwhelmed by loss and negative life experiences and comes to identify with an existence defined by despondency and despair. The person who takes drugs does so to mute or blunt the negative experiences of life or, alternatively, to escape temporarily into a state of higher consciousness.

Despite the obfuscations of psychiatrists and mental health organizations, mental illness is not simple brain disease, nor is it known to be related to chemical imbalances in the brain. It is much more accurately described, in my view, as a uniquely human method of dealing with the realities of life.

Mark L. Ruffalo, L.C.S.W., is a psychoanalyst in private practice in Tampa, Florida. He serves as an affiliate assistant professor of psychiatry and an adjunct instructor of social work at the University of South Florida and has previously served as membership chair of the Academy for the Psychoanalytic Arts.


Frances, A. J. (2013). Saving normal: An insider's revolt against out-of-control psychiatric diagnosis, DSM-5, big pharma, and the medicalization of ordinary life. New York, NY: HarperCollins.

Kraepelin, E. (1904). Lectures on clinical psychiatry. New York, NY: Hafner.

Pies, R. W. (2011, July 11). Psychiatry's new brain-mind and the legend of the "chemical imbalance". Psychiatric Times. Retrieved from

Stephen, J. F. (1873). Liberty, equality, fraternity. London: H. Elder, and Co.

Szasz, T. S. (1961). The myth of mental illness: Foundations of a theory of personal conduct. New York, NY: Harper and Row.