In 2001, The Academy of Psychosomatic Medicine (APM) and The Association of Medicine and Psychiatry applied to the American Board of Psychiatry and Neurology (ABPN) for the recognition of "Psychosomatic Medicine" as a subspecialty field of psychiatry. Following ABPN approval, it was submitted for consideration to the American Board of Medical Specialties (ABMS). Formal support for this proposal has also been received from the American Psychiatric Association (APA), ABPN, and the Residency Review Committee (RRC) of the Accreditation Committee for Graduate Medical Education (ACGME).

In approving this new subspecialty, APA and ABPN recognized the benefits for general psychiatry. Its creation would not mean that only subspecialists should provide psychiatric consultations, but that some subspecialists may be needed for the more difficult, complex patients in specialized treatment settings. There probably won’t be enough psychosomatic medicine subspecialists to perform all psychiatric consultations. This is analogous to the other subspecialties of psychiatry (i.e., it was never intended that geriatric psychiatrists should treat all elderly patients, or that only forensic psychiatrists could serve as expert witnesses). The American Psychiatric Association and ABPN recognized that a stronger psychosomatic medicine subspecialty would enhance the training of general psychiatry residents in caring for the medically ill, as well as improve training of medical students and residents in other medical specialties in the psychiatric aspects of patient care. In addition, psychosomatic medicine psychiatrists are a major source of referrals for general outpatient psychiatrists and psychiatry inpatient units.

In 1818, Johann Christian Heinroth was the first to use the term "psychosomatic" when discussing causes of insomnia. The phrase "psychosomatic medicine" is believed to have been introduced by Felix Deutsch around 1922 (1). Edward Billings introduced the concept of liaison psychiatry at the University of Colorado, supported in part by an initiative of the Rockefeller Foundation in 1935, which funded consultation-liaison/psychosomatic medicine units there and at three other university hospitals. The American Psychosomatic Society was founded in 1936, and the Academy of Psychosomatic Medicine in 1954. James Eaton, Director of the Psychiatry Education Branch at the National Institute of Mental Health (NIMH) provided inspired leadership with the development of training grants for consultation-liaison psychiatry fellowships in the late 1970s that significantly enlarged the number of expert clinician-teachers. Recognizing the need for more research at the interface with medical illness, NIMH developed a series of Research Development Workshops for psychiatrists in consultation-liaison psychiatry in 1985. By 1991 there were 55 consultation-liaison fellowships registered with the Academy of Psychosomatic Medicine. With the support of the APA, the Academy of Psychosomatic Medicine first applied to ABPN for subspecialty status for consultation-liaison psychiatry in 1992. At that time, ABPN raised concerns about the name and scope of the proposed subspecialty. The American Board of Medical Specialties subsequently instituted a moratorium on all new subspecialties. Ultimately, APM submitted a new application for subspecialty status in 2001.

The name of the field was changed from consultation-liaison psychiatry to psychosomatic medicine after extensive discussion within APM, APA, and ABPN. Consultation-liaison was deemed misleading both because many other psychiatrists perform consultations and the defined subspecialty provides direct care as well as consultation and liaison. Psychosomatic medicine psychiatrists provide liaison and treatment in primary care settings and care to complex medically ill patients in specialized settings like intensive care units (ICUs), transplant programs, dialysis centers, burn units, and human immunodeficiency virus (HIV) clinics. They staff inpatient consultation services and medical-psychiatry inpatient units. Other names considered (e.g., medical psychiatry, psychiatry in the medically ill) were determined to have additional drawbacks. Ultimately, it was decided to return to the historically rooted name psychosomatic medicine, which was already in use by leading organizations and journals in the field. Thus, the name of the subspecialty is intended to reflect a conceptualization of "psychosomatic medicine" as broadly referring to mind and body interactions in patients who are ill rather than as a reductionistic theory of psychogenic causation of disease.

Some of the early roots of the field lie in the work of scientific pioneers interested in mind-body interactions such as Cannon’s description of the "fight/flight response," Wolff & Wolff’s studies of gastric secretion, and Pavlov’s work on conditioning of both the voluntary and autonomic nervous systems. Psychiatrists such as Flanders Dunbar, Franz Alexander, and Felix Deutsch drew on clinical experience to develop theories about how emotional conflicts may result in physical symptoms and real medical disorders. Holmes and Rahe studied the role that life change may play in promoting illness (4). George Engel (a psychoanalytically trained internist) and psychiatric colleagues studied delirium, chronic pain, and psychological adaptations to illness, and he developed the influential paradigm known as the Biopsychosocial model. Modern research in fields such as psychoneuroendocrinology and psychoneuroimmunology evolved out of the work of these pioneers. The field’s evolution was further aided and chronicled by the development of several influential journals (t1) and classic texts (t2) and by the creation of national and international organizations devoted to related interests (t3).

Eventually, the growth of psychosomatic medicine was reflected in both the practice and training of psychiatric residents. In 1961, the recommendations of the Accreditation Council for Graduate Medical Education for training in psychiatry encouraged "sufficient contact through consultation and associated conferences with the services other than their own, such as general medicine, neurology, surgery, and pediatrics, so that the residents may learn to apply their special training relevantly and helpfully to these fields." Consultation-liaison and psychosomatic medicine began to become integrated into the core of psychiatric resident training by the late 1960s. By the 1980s, the RRC required all psychiatry residency programs to "provide systematic instruction and substantial experience in… the diagnosis and treatment of psychophysiologic disorders, and psychiatric consultation or liaison psychiatry involving patients on other medical and surgical services."

The evolution of psychosomatic medicine knowledge and training has naturally led to the development of fellowship programs. Subspecialty training has been available for more than 25 years in the United States. As of 2001, there were 32 consultation-liaison psychiatry fellowship programs that registered with the Academy of Psychosomatic Medicine. There were also 48 combined residencies in psychiatry with internal medicine, family practice, pediatrics, or neurology. Approximately 800 psychiatrists have completed subspecialty training in this area, the majority of these in the last decade (Academy of Psychosomatic Medicine, unpublished survey data, 2001). As a large part of their day-to-day practice, well over 2,500 psychiatrists in the United States provide care to complex medically ill patients in a variety of healthcare settings. Of these, about 800 are active members of the Academy of Psychosomatic Medicine.

The existence of the field of psychosomatic medicine as a separate subspecialty discipline within psychiatry rests upon the specialized knowledge base it has developed regarding psychiatric aspects of medical illness. As substantial growth in the field has occurred over the last 20—30 years, a cadre of scholars and investigators has emerged. Psychosomatic medicine research currently involves a wide spectrum of investigations that analyze the medical illness-psychiatry interface. Important contributions related to the psychiatric aspects of acquired immune deficiency syndrome (AIDS), cancer, transplantation, cardiology, neurology, pulmonary, renal and GI diseases, and obstetrics-gynecology have been made. In each of these areas, first-generation studies identified the extent and nature of psychiatric morbidity associated with the most common diseases and hospitalization itself. More sophisticated second generation cross-sectional epidemiological studies established the prevalence rates of a broader range of psychiatric disorders in earlier studied illnesses as well as less common and newly recognized disease states. These latter studies have defined, for example, the complex presentations of depression in cancer patients, the psychiatric features of several paraneoplastic syndromes, traumatic stress reactions related to receiving a life-threatening diagnosis, and the association between depression and interferon treatment.

In some cases, research has extended our knowledge about genetic, neurochemical, and behavioral factors contributing to the development of psychiatric disorders among complex medically ill populations. This work has shown that many different mechanisms are involved. Examples include the relationship between the location of stroke and major depression (9,10), the role of childhood sexual abuse in chronic pain syndromes (11), and research on the development and neuropathology of delirium (12,13). Such findings have, in turn, led to more rational intervention studies focused on managing and, hopefully, reducing the rate of occurrence of these disorders.

A long-standing psychosomatic medicine interest has defined the relationship between emotional factors and disease development. Recent studies have demonstrated the dramatic impact of comorbid psychiatric conditions on the course and outcome of several medical illnesses. For example, depression has been shown to increase the risk of recurrence and mortality from myocardial infarction (14), the risk of stroke in hypertensive patients (15), and physical aggression and functional dependency in Alzheimer patients (17). Depression has also been shown to worsen glycemic control in diabetic patients (16) and double the mortality of stroke patients (18). Studies have examined the effects of comorbid psychiatric disease on health costs (19). Psychiatric disorders have been shown to increase the length of hospital stay and re-hospitalization rates in numerous illnesses (20,21). Cost-effectiveness studies have demonstrated the value of psychosomatic medicine interventions in hospital and outpatient populations (22,23).

Ultimately, the primary objective for psychosomatic medicine psychiatrists is the improvement of psychiatric care of patients with complex medical conditions. These patients are encountered in general and chronic care hospitals, home healthcare settings, offices of primary care or specialist physicians, and in many other healthcare environments. Psychosomatic medicine research has documented potentially severe psychiatric morbidity in these patient populations and the benefits to patients and the healthcare system of having psychiatric care that is provided by psychiatrists with psychosomatic medicine expertise.

Patients in the general hospital have the highest rate of psychiatric disorders when compared to community samples and patients in primary care settings (24). Compared to community samples, depressive disorders among patients in general hospitals are more than twice as common, major depression is two to three times as common, substance abuse two to three times as common, and somatization disorders more than 10 times as common (24). Delirium occurs in 18% of general hospital patients (25), a rate much higher than that of the community samples. These high rates of psychiatric disorders in general hospital patients may result from reactions to or complications from medical disorders and treatments; a higher rate of medical comorbidity among patients with psychiatric disorders due to psychophysiological factors (e.g., depression in cardiovascular disease); unhealthy life styles among patients with psychiatric disorders; and disproportionately more frequent use of medical services by persons with mental disorders, especially somatoform disorders.

Huyse in the Netherlands has referred to the general hospital as a filter that can identify the high concentration of patients with psychiatric disorders (26). The patients who pass through its portals need recognition, appropriate diagnosis, initiation of treatment, and referral for the followup psychiatric care they would otherwise fail to receive. Failure to identify, evaluate, diagnose, treat, and achieve symptom resolution results in significant adverse outcomes. For example, depression, dementia, and delirium, three common disorders found among general hospital patients, are associated with worse medical outcomes and higher utilization of medical care, both in the hospital and after discharge (27,28). Yet failure to treat these disorders occurs all too frequently. Less than one in five patients with agitated delirium receives the treatment of choice, a neuroleptic medication, in the hospital (29). When delirium is unrecognized and untreated in the hospital, it results in unnecessary placement in nursing homes instead of discharge to a patient’s home (30). Patients with depression who are not diagnosed and do not begin treatment during their medical hospitalization only have an 11% chance of receiving treatment for depression in the year following discharge (31). Untreated depression is associated with higher medical utilization after hospital discharge and higher mortality and morbidity in coronary disease, hypertension, diabetes, and strokes (24,32).

Despite the evidence showing the importance of the identification and initiation of treatment of psychiatric disorders in the general hospital and in primary care settings, in the absence of an active on-site psychosomatic medicine service, the rate of referral to psychiatry is distressingly low. While the incidence of psychiatric disorders in the general hospital has been reported to be as high as 30%-40%, the rate of psychiatric referral is 1%—2% (33). The referral rate rises 4 to 10 fold when an active psychosomatic medicine service is integrated with the medical/surgical staff (33) in collaborative programs to identify and initiate treatment for psychiatric disorders.

In addition to psychiatric disorders in medical/surgical patients in the general hospital, patients with several specific medical illnesses have higher rates of psychiatric comorbidity. These patients might benefit from psychiatric evaluation and treatment that may not be readily available in the absence of psychosomatic medicine services that work closely with their medical and surgical colleagues. For example, many dialysis patients experience difficulties in adjusting to placement of the shunt, dependence on a machine, multiple needle sticks, and the observation of their blood circulating outside their bodies. For dialysis treatment to be successful, problems with compliance must be handled. Failure to adhere to a strict diet and cooperate in receiving the necessary frequency of dialysis can be fatal. Delirium and dementia may result from the dialysis itself. Depression is common and independently predicts a lower survival rate (34).

Organ transplant programs frequently incorporate psychiatric evaluation of transplant candidates, with psychiatrists playing a vital role pre and posttransplant. Psychopathology may adversely affect patients during a long wait for an available organ (35). Delirium during the postoperative period may be severe. Even relatively minor disruptions in postoperative compliance with immunosuppressant medication may result in graft rejection and death. Psychopharmacologic treatment in transplant patients may be particularly complicated, in part due to the powerful immunosuppressant medications used in these patients.

Psychiatric care may be invaluable in addressing the traumatic impact of a cancer diagnosis, which may abruptly convert previously healthy individuals into a patient teetering precariously between remission and life or treatment failure and death. Cancer patients may need psychiatric intervention at all stages of disease (36). Problems may include chemotherapy-induced delirium, conditioned nausea and vomiting, central nervous system (CNS) paraneoplastic and metastatic syndromes, antiemetic akathisia, and neuropsychiatric complications of radiation therapy and bone marrow transplantation. Psychosomatic medicine psychiatrists may play a leading role in pain management and palliative care, as well as collaborate with oncology services in helping terminally ill patients deal with the process of death and dying.

Human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) patients may present special diagnostic and treatment challenges for psychiatrists, including symptoms that may be caused by opportunistic infections, neoplasm, antiviral drugs, and the HIV virus itself. Serious psychopathology and substance abuse also occurs frequently in HIV patient populations (37).

Many other specialized patient populations are a focus of care by psychosomatic medicine psychiatrists. A few examples include postcardiac surgery delirium; anxiety syndromes in patients with defibrillators, balloon pumps, and other cardiac assist devices; psychosocial issues in infertility programs; and psychopathology caused by neurological diseases such as stroke, traumatic brain injury, multiple sclerosis, and Parkinson’s disease.

Beyond working with the psychiatric sequelae of medical illnesses, psychosomatic medicine psychiatrists also have developed other skills that are critical for successful functioning at the interface with medicine. These include:

Psychiatrists interested in psychosomatic medicine have long acted as liaisons between psychiatry and other medical practitioners, most often through provision of psychiatric consultation in medical/surgical hospitals. However, psychosomatic medicine psychiatry is more than consultation-liaison services. Psychosomatic medicine psychiatrists also provide training to nonpsychiatric residents, particularly in internal medicine, family practice, pediatrics, obstetrics/gynecology, and neurology. Psychosomatic medicine psychiatrists have assisted with the development of practice guidelines to treat patients with comorbid medical illness, such as the Agency for Health Care Policy and Research (AHCPR) Guidelines for Depression in Primary Care (38), the AHCPR Cancer Pain Management Guideline (39), and the APA Practice Guidelines (25). Psychosomatic medicine psychiatrists have developed model psychiatric curricula for the American Society for Clinical Oncology and the National Cancer Center Network. Psychosomatic medicine psychiatrists have played a significant role in teaching about psychiatric disorders at scientific meetings of the American College of Physicians, the Society for General Internal Medicine, the American Association for Family Practice, the American College of Obstetrics and Gynecology, and many other organizations. Psychosomatic medicine psychiatrists also have played leading roles on medical center ethics committees, contributing specialized expertise regarding end of life decisions, capacity/competency, involuntary treatment, boundary violations, and other doctor-patient relationship problems (Academy of Psychosomatic Medicine Task Force on Ethics, unpublished data).

The clinical, educational, and scholarly activities of psychosomatic medicine psychiatrists are not unique and naturally overlap with those of general psychiatrists and other psychiatric subspecialists. Many psychiatrists provide consultations to their medical colleagues, treat patients who have comorbid medical and psychiatric disorders, and help train other health care professionals. Psychiatric subspecialists in pain management have the most experience and training for the treatment of pain disorders, and the same is true of geriatric psychiatrists for psychiatric disorders in the elderly. Child and adolescent psychiatrists, not adult psychosomatic medicine psychiatrists, almost always provide consultation-liaison services for pediatric patients. What differentiates psychosomatic medicine from general psychiatry and other subspecialties is its particular focus on patients whose psychopathology is complicated by more complex medical disorders, often seen in specialized settings like the ICU, transplant program, or HIV clinics.

Psychosomatic medicine has evolved from its beginnings in psychophysiology and psychoanalysis to become a subspecialty in the practice of psychiatry devoted to the psychiatric care of the complex medically ill, while also providing consultation and liaison to the spectrum of other medical specialties. Formal recognition as a subspecialty will strengthen psychosomatic medicine and enhance its further growth. The creation of more psychiatrists with expertise in psychosomatic medicine will help address the unmet psychosocial and psychiatric needs of the medically ill, improve the quality of education and training in psychiatry and in other areas of medicine, and promote integrative biopsychosocial research and patient care.