THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINEVolume 7, Supplement 1, 2001, pp. S-83S-92Mary Ann Liebert, Inc.

The Physiology of MindBody Interactions: The Stress Response and the Relaxation Response

GREGG D. JACOBS, Ph.D.

ABSTRACT

There are key differences between mindbody medicine and alternative medicine. A centraltenet of mindbody medicine is the recognition that the mind plays a key role in health and thatany presumed separation of mind and body is false. Alternative medicine, however, does notfocus on the role of thoughts and emotions in health and, therefore, is separate from mindbodymedicine. Also, while there has been little scientific research on alternative medicine, the litera-ture on mindbody medicine comprises more than 2000 peer-reviewed studies published in thepast 25 years. The groundwork for understanding the physiology of mindbody interactions wasestablished by pioneering studies in the 1930s by Walter Cannon, and in the 1950s by WalterHess and by Hans Selye that led to an understanding of the fight-or-flight response. Later workby Holmes and Rahe documented measurable relationships between stressful life events and ill-ness. Other research has shown clinical improvement in patients treated with a placebo for a va-riety of medical problems. The effectiveness of placebo treatment can be interpreted as com-pelling evidence that expectation and belief can affect physiological response. Recent studiesusing spectral analysis and topographic electroencephalographic (EEG) mapping of the relax-ation response demonstrate that by changing mental activity we can demonstrate measurablechanges in central nervous system activity. These, and other, studies demonstrate thatmindbody interactions are real and can be measured.

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It is an honor to be here to represent HarvardMedical School, Harvard Medical Interna-tional, and the MindBody Medical Institute atHarvard Medical School. It is also an honor toaddress our friends, colleagues, and gracioushosts here at the Asan Medical Center. In myfirst talk, Id like to talk about the physiologyof mindbody interactions.

First of all, let me define mindbody medi-cine. Yesterday, mindbody medicine was de-scribed as part of complementary medicine. Infact, there are some key differences betweenmindbody medicine and complementary or

alternative medicine. First, one of the key def-initions of mindbody medicine is that themindthat is, thoughts and emotionsaffectshealth. So one of the central tenets of mindbody medicine is the recognition that the mindplays a key role in health and that Cartesiandualismthat is, separation of mind andbodyis false. The media, the public, andhealth care professionals, however, often con-ceptualize mindbody medicine as alternativemedicine, and include mindbody medicinewith therapies like acupuncture or herbalremedies. In fact, most alternative medicine

Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts.

treatments, such as acupuncture or herbalremedies, have nothing to do with mindbodymedicine because they do not focus on the roleof thoughts and emotions in health.

A second difference between mindbodymedicine and complementary or alternativemedicine is that alternative medicine is notonly young in terms of a science, but there iscomparatively little research on alternative andcomplementary medicine relative to mindbody medicine. In fact, mindbody medicine isbased on more than 2000 scientific studies thathave been published in peer-reviewed journalsin the last 25 years.

My contention is that, because mindbodymedicine involves this kind of empirical re-search base, it should not be considered alter-native and, in fact, should be considered main-stream. For example, in the United States, wehave half a dozen journalsscientific peer-re-viewed journalsthat are specifically devotedto mindbody medicine. Some of the journalsinclude biofeedback and self-regulation, be-havioral medicine, psychosomatic medicine,and health psychology. There are dozens ofother journals including the Journal of the Amer-ican Medical Association and even the New En-gland Journal of Medicine that publish studies onmindbody medicine.

Another difference between mindbodymedicine and alternative medicine is the con-cept of self-care. In fact, Herbert Benson of theHarvard Medical School, who is one of the pi-oneers in mindbody medicine, uses the modelof what he terms the three-legged stool, inwhich mindbody medicine is not intended toreplace standard medical care, such as surgeryand drugs, but should be used in conjunctionwith it. In Dr. Bensons model of the three-legged stool, each legpharmaceuticals, sur-gery and procedures, and self-help techniquesin the form of mind-body interventionsallwork to support health (Benson, 1996). One ofthe pluses of mindbody medicines self-helptechniques is that patients are actually giventechniques that they learn and practice inde-pendently from an external agent or a health-care professional. Once they have learned thetechniques, they can use the techniques on theirown. That empowers the patient and increasesthe patients sense of self-control, which, as I

will talk about in my second lecture, is actuallyimportant for health maintenance. Developinga sense of control is an attitude and a belief thatis associated with improved health and lon-gevity.

Id like to talk next about some of the scien-tific underpinnings of mindbody medicine bystarting with what is called the fight-or-flightresponse, which, in a very real sense, formedthe basis of the physiology of mindbody in-teractions. First, mindbody medicine is the re-sult of a long history of research on the psy-chophysiological connections between the brainand the nervous, hormonal, and immune sys-tems. This research initially focused on stressand its effects on the body.

The first person to conduct research inmind-body medicine, although they didntterm it mindbody medicine then, and whostudied the fight-or-flight responseor whatwe now term the stress responsewas Wal-ter Cannon, a physiologist at Harvard Med-ical School who conducted his research in the1930s. Cannon documented the physiologicaleffects of what he termed the emergency re-action, which he defined as an acute physio-logic reaction that prepares the organism forfighting or fleeing. Cannon described thephysiologic changes associated with the fight-or-flight response as being characterized byincreased sympathetic nervous system activ-ity, increased central nervous system arousal,and increased skeletal-muscle activity. Hewent on to define specific correlates of thesephysiologic changes, including reduced bloodflow to the gut and extremities during fight orflight; increased blood flow to the muscles,heart, and lungs to aid in fighting or fleeing;and increased blood sugars among manyother changes (Cannon, 1932).

Interestingly, Cannon also hypothesized thatstress not only induces these physiologicchanges, but he also believed that stress pre-cipitates sudden death via ventricular fibrilla-tion based on his studies on voodoo death.Later in the 1950s, the Swiss physiologist, Wal-ter Hess, was awarded the Nobel Prize for hisresearch on electrical stimulation of the hypo-thalamus in cats. Hess initially documentedwhat he termed the ergotropic responses,which was his term for the emergency reaction.

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He defined the ergotropic response as a hypo-thalamically mediated response. It is charac-terized by increased sympathetic, cortical, andskeletal muscle activation. Hess would alsodocument an opposite response that we nowterm the relaxation response, which I will re-turn to shortly (Hess, 1957).

The other key physiologist credited with theinitial research on the effects of stress and emo-tions on the body is Hans Selye, who, in the1950s, studied the neuroendocrine effects of thefight-or-flight response and the resulting gen-eral adaptation syndrome. Selye conceptual-ized stress and its effects on the body as con-sisting of three phases that make up the generaladaptation syndrome. The first phase is analarm phase in which the fight-or-flight re-sponse is elicited for mobilization and gearingup for fight or flight. A second phase is calleda resistance phase in which the organism fightsthe stressor, but the acute fight-or-flight re-sponse ceases. And then, a third phase, whichhe termed the exhaustion phase, in which theorganism can no longer adapt to the stressor.It is this third phase, the exhaustion phase, thatSelye showed could result in illness, includingshrinkage of thymus, the spleen, and the lymphnodes, also peptic ulcers, and, in some cases,death (Selye, 1956).

After or around the time that Hans Selye wasconducting his research, two scientists devel-oped a model in which they were able to beginto document the effects of stress, in particular,stressful life events, not just on the body, but onmorbidity and mortality. This was the Holmesand Rahe Schedule of Recent Experiences,which is an inventory that assigns numerialranking to various life events, from divorce tochanging jobs, or moving, all the way down toa recent illness (Rahe, 1964). Holmes and Raheand subsequent epidemiologic research on therelationship between stress and illness, docu-mented consistent, measurable relationships be-tween stressful life events and illness. For ex-ample, stressful life events have been linked tosudden cardiac death, pregnancy and birth com-plications, diabetes, and overall susceptibility toillness. In 1992, a review by two National Insti-tutes of Health scientists in the Journal of theAmerican Medical Association noted the role ofstress in autoimmune diseases, coronary heart

disease, gastrointestinal disorders, chronic pain,and a range of other medical as well as psychi-atric disorders (Chrousos and Gold, 1992). In allof these disorders it is believed