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How Medicine Relegated Mental Illness to Secondary Status

Psychiatry now embraces medicine’s disease-only model of care.

Key points

  • The Scientific Revolution produced the mind-body split and disease model that psychiatry embraces.
  • Psychiatry emerged in the 19th century and initially espoused holistic principles.
  • In the last half of the 19th century, however, psychiatry fully embraced the disease model.
  • Poor mental health care today stems from the disease model and may represent a human-rights violation.
Source: CC-BY-SA-3.0

Mental health care never had a chance. Here’s what happened (1, 2).

From its very inception, the Scientific Revolution of the 16th and 17th centuries doomed mental disorders and other psychosocial features of patients. It grounded modern scientific medicine theoretically and philosophically in the “mind-body split.” This divorced patients’ psychological/mental and social issues—where our humanity resides—from physical disease problems. An almost exclusive interest in physical diseases resulted, and guides medicine to this day. Psychiatry developed as a small subset of medicine in the 19th century and would also adopt this isolated focus on physical diseases after first exploring a more holistic, person-centered approach.

The mind-body split began in the 16th century when Andreas Vesalius identified the scientific method and used it to produce his revolutionary findings in anatomy. Forebodingly for mental illnesses, however, he excluded the head from his dissections; the powerful Catholic Church required this. They viewed the head as the site of the mind and spirit, their province alone. This launched scientific medicine away from patients’ human elements. In the 17th century, philosophers Rene Descartes, Thomas Hobbes, and John Locke provided a philosophical rationale that more definitively excluded mind issues from medical science, leaving them to the Church. In the 18th century, the isolated disease interest spread to practitioners when pathologists first recognized that the abnormal organs they observed at autopsy represented a disease and caused patients’ symptoms, an idea that soon would govern all clinical medicine. The new direction led clinicians to change from a holistic focus on the entire person to concentrate only on physical symptoms—as a clue pointing to an underlying disease. But the isolated interest on physical diseases did not benefit patients until the 20th century when the diagnosis and treatment advances we experience today as routine progressed at an astounding pace to address physical disorders.

Where did psychiatry and mental health fit in? Prior to the 19th century, mental care took place in patients’ homes and through community assistance. More severe disorders received help under the aegis of the Church in medieval hospitals, monasteries, and religious houses.

The new concept of diseases causing symptoms, however, prompted a secular shift in the 19th century. It opened the door for physicians to take charge of mental institutions, initially called “lunatic asylums.” A corps of specialists slowly materialized and psychiatry was born as a discipline. By the mid-19th century, psychiatry became a formal organization, the Association of Medical Superintendents of American Institutions for the Insane. They published their own scientific journal, the American Journal of Insanity, now known as the prestigious American Journal of Psychiatry.

Terrifying to patients and doctors alike, early hospitals infamously employed punitive measures, such as chain restraints, corporal punishment, and strait jackets. Repelled by such conditions, the new psychiatric hospitals replaced the old asylum care with what they called “moral treatment.” This resumption of holistic Hippocratic traditions valued the patient in his or her psychological, emotional, and social realms. With this renewed interest in mental illness, the asylum movement accelerated, and more and more patients came under care.

Although the asylums made little positive impact on patients’ mental health, psychiatry itself made significant progress in diagnoses by first classifying mental disorders. The academic foundations of psychiatry then continued to evolve, culminating by the late 19th century with such illustrious leaders as Emil Kraepelin and Sigmund Freud. Psychiatrists embraced the broader psychological and social dimensions as important even though they remained wedded to the idea of physical disease of the brain as the origin of mental disorders—despite an absence of evidence.

As the 20th century dawned, the diminutive field of psychiatry continued its attention to patients’ psychological and social aspects, retaining a person-centered, humane focus on mental health. Freud’s articulation of the unconscious and its influence on mind-based issues fostered this, as did his patient-centered interviewing technique that identified mental issues in patients. Appreciation of human psychological factors got a boost following the world wars with identification of what we now call posttraumatic stress disorder; doctors had puzzled over how distressed soldiers could have severe physical symptoms without an underlying disease or injury.

Despite its promising beginning, however, psychiatry retrenched by the mid-20th century and fell further prey to its long-term hope of finding brain diseases to explain mental disorders. The discovery of lithium in 1948 and chlorpromazine in 1952 revolutionized care for bipolar disorder and schizophrenia, respectively. This also rekindled the belief in a physical disease orientation, now that altered brain chemicals led to mental illnesses. Benzodiazepines were discovered shortly thereafter as psychiatry embarked on the progressively more narrow course of seeking chemical explanations for mental disorders, ironically scrapping its seminal early patient-centered advances.

The physical disease orientation of psychiatry continues unabated even though there has been little significant improvement in mental illness outcomes since the 1960s, according to the former Director of the National Institute of Mental Health, Thomas Insel (3). He compellingly captures the problem of present mental health care in his new book, Healing: Our Path From Mental Illness to Mental Health. He proposed that the poor quality of modern mental health care constitutes a basic human rights violation (4). For example, only 25% of all patients with a mental illness receive any care at all, and most of that does not meet standards. Compare this to 70% of patients with physical diseases receiving high quality care (5).

CC-BY-SA-4.0; Self-published work
Source: CC-BY-SA-4.0; Self-published work

To improve mental health care, psychiatry must get rid of the mind-body split philosophy and its disease model. All other sciences did this long ago by adopting a systems view; for example, physics replaced the Scientific Revolution’s Newtonian physics with relativity and quantum theories 100 years ago. A systems view of any scientific discipline means that all parts of the science must be seen as integrated and interacting. For psychiatry, this means integrating patients’ psychological and social features with its disease focus. Psychiatry already has a systems-based model, the biopsychosocial model, but it has received little more than lip service since George Engel articulated it in 1977.

The reluctance of psychiatry to jettison the disease-only model prompts concern. And that may make us wonder if the public and its political representatives need to intervene to improve mental health care.


Porter R. The Greatest Benefit to Mankind -- A Medical History of Humanity. New York: WW Norton and Company; 2009.

Browne S, Burton M. The History of Psychiatry -- Important Figures & Developments: CreateSpace Independent Publishing Platform (1629); 2015.

Insel TR. Balancing Immediate Needs with Future Innovation. Director's Blog. Bethesda, MD: NIMH; 2012.

Insel TR. Healing--Our Path from Mental Illness to Mental Health: Penguin Press; 2022.

Dept. of Health and Human Services. Mental Health and Mental Disorders. Healthy People 2010. Washington, D.C.: U. S. Government Printing Office; 2000

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