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On Categorizing Human Behavior as Disease

by Mark L. Ruffalo

"To the man who wants to use a hammer badly, a lot of things look like nails that need hammering." - Mark Twain

In 2013, the American Psychiatric Association released the fifth edition of its Diagnostic and Statistical Manual of Mental Disorders (DSM-5), culminating a 14-year and $30 million revision process, chaired by David Kupfer, M.D., a professor of psychiatry at the University of Pittsburgh. During the revision process, many individuals and organizations voiced opposition to specific changes and proposed additions to the manual. Amongst the most heated debates surrounded proposed disorders like gambling disorder, binge eating disorder, premenstrual dysphoric disorder, and hypersexual disorder. Some of those who spoke out are prominent and respected figures within the field of psychiatry. Allen Frances, M.D., professor emeritus at Duke and chair of the DSM-IV Task Force, commented frequently on the broadening of the definition of mental disorder and DSM-5's intent to medicalize a greater range of human behavior. Nevertheless, very few authors have considered the validity of the DSM as a whole. The release and gradual adoption of DSM-5 provides us the opportunity to re-examine the question of what counts as disease and explore the practical and philosophical consequences of classifying human behavior as illness.

To understand how the term 'mental disorder' is used in psychiatry, one must first understand the specific meaning of the term 'disease' in the rest of medicine. To pathologists—those physicians who study disease—and to other non-psychiatric physicians, disease refers to structural or functional alteration of cells, tissues, or organs. To be a true disease, the entity must first somehow be capable of being approached, measured, or tested in a scientific manner. Second, to be confirmed as a disease, a condition must demonstrate pathology at the cellular or molecular level. True diseases are implied by the patient's symptoms (i.e., complaints) and confirmed through signs (using objective medical tests). In psychiatry and the mental health disciplines, disease (or "disorder") refers to an abnormal living pattern, difficulty in interpersonal functioning, or other problems in the way a person feels, thinks, or behaves. There exists no diagnostic medical test to determine the presence or absence of mental disease, and the diagnosis of mental disease is based solely on subjective symptoms, not objective signs. Even schizophrenia, long considered the most severe mental illness, lacks any defining physiological marker and cannot be diagnosed by any test.

Psychiatrists often claim that the "biological basis" of mental illness can be established from the effectiveness of psychotropic medications and from brain imaging research. But what is meant by "biological basis?" Anything a person does may be said to have a "biological basis" insofar that all human behavior is initiated by the body. Activation of certain brain areas on imaging scans isn't evidence of disease. All human behavior correlates with certain changes in neural circuitry, but the distinction between "normal" and "pathological" functioning is always made within the social context and reflects the norms and values of society. The claims about medication are similarly baseless. The fact that psychiatric medications seem to "work" says nothing about the nature of the human problems called mental disorders. Even so, the research on the effectiveness of psychiatric medications is less than convincing. As demonstrated by Irving Kirsch's work on the placebo effect, the effectiveness of antidepressant drugs is no better than placebo, leading Kirsch himself to suggest that depression may not be a disease at all. Psychiatrists also claim that research is bringing psychiatry closer to diagnostic tests for mental illness. But psychiatrists have been saying this for a hundred years.

In the absence of objective diagnostic tests in psychiatry, there exist no boundaries to the category called mental illness. The range of human behavior that can be described as sick or ill is literally limitless. Any behavior or living pattern that deviates from certain social norms can be described—and officially designated—as mental illness in need of treatment. In years past, it was homosexuality, political opposition, and drapetomania (Black slaves who wanted to escape to freedom). Today it is sadness, excessive drinking, and childhood misbehavior. In saying that mental disorders are not literal diseases, I do not deny the reality of the experiences of people labeled mentally ill. People surely suffer, sometimes greatly, but suffering alone has never been a sufficient criterion for disease. (Usually, however, mental disorders cause more suffering in others than in the person said to be "suffering" themselves.) It is, of course, entirely possible that some of the disorders listed in the DSM are literal brain diseases. Throughout the history of psychiatry, diseases once considered psychiatric—neurosyphilis, epilepsy, Alzheimer’s disease—were discovered to be actual diseases of the brain. However, the discovery that a mental disorder is actually a brain disease does not prove its existence as a mental disorder; it only proves that it is a brain disease. Such a discovery says nothing of the existence of a category of disease called "mental illness." In short, neurological (medical) diseases are diseases in the literal sense, while psychiatric disorders are diseases in the metaphorical sense. Many human problems may be described metaphorically as diseases. We often hear people speak of a "sick economy" or "sick culture." There is little harm in resorting to these metaphors, except that there is danger that some people will take the metaphor literally.

What are the consequences of classifying behavior as disease? In other words, who benefits and who is harmed from the process of medicalization? Insofar as psychiatric disorders are treated with medication, the pharmaceutical industry is a major winner. Much has been written about the influence of the pharmaceutical industry on the practice of psychiatry and psychotherapy, and I will not belabor that point here. Needless to say, there is big money in describing human problems as mental diseases. Psychiatrists and other mental health professionals benefit from medicalization because it reinforces their position as experts on mental illness and creates tens of thousands of new prospective patients, sometimes overnight. In the legal arena, individuals can be excused from criminal offenses because their behavior is said to be the result of mental disease. Economically, insurance companies are forced to pay for "treatment" of these "disorders" due to "mental health parity" laws, driving up the cost of health care for everyone. In the clinical setting, patients are taught that they are not responsible for their action because they lack the ability to choose. (This is most clear in addiction treatment, wherein patients are told they literally cannot control their drug-taking.) Oftentimes, individuals are deprived of liberty and committed to psychiatric hospitals against their will. In the broader philosophical sense, the entire concept of free will is denied. Human behavior is said to be fully determined by forces outside of the person's control.

Millions upon millions of dollars are allocated each year to fund research aimed at discovering the biological etiology of mental illness. Scientists have probed, prodded, dissected, and scanned thousands of brains—both human and animal—in search of the causes of schizophrenia, depression, bipolar disorder, and drug addiction. Yet, such research has failed to yield a single demonstrable test for mental illness. In fact, there is a growing concern amongst the scientific community that brain research does not reveal anything about the nature of psychiatric disorders. It is no wonder that neuroscience has failed in this quest: Mental disorders are not diseases of the brain but rather labels constructed socially to describe deviant and maladaptive human behavior. The DSM informs clinicians to "rule out" organic disease before making a diagnosis of mental illness, tacitly acknowledging that psychiatric disorders are something other than organic. But can there be such a thing as inorganic disease?

In recent years, some progress has been made by clinicians adhering to a "recovery model" of mental illness and by authors and organizations opposing the addition of nonexistent diseases to the DSM. But by and large these efforts are fruitless because they ignore the larger problem: the illegitimacy of the DSM as a valid medical instrument. As the late Thomas Szasz warned more than fifty years ago, the laws of psychology cannot be formulated independent of the laws of sociology. Any classification of human behavior as disease relies upon the social context. Unfortunately, until the DSM is abolished as the legitimizing document of psychiatry, individuals will continue to be deprived of liberty and responsibility in the name of treatment for mental illness.


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.