Though cloaked in the mystique of their calling, doctors do not see themselves as workers of miracles. They believe instead in technique and technology and in treatments that can be proven effective. Yet the more they understand about disease and recovery, the more skeptical they may become about phenomena that defy understanding. Traditionally their profession has given little credence to the idea that the immune system, the body's natural defense against illness and infection, can be affected by a patient's state of mind. Now researchers in the fledgling branch of medical science known as psychoneuroimmunology are beginning to challenge this view as short-sighted. A pioneer in the field is Dr. Steven Locke, 40, associate director of the Psychiatry Consultation Service at Boston's Beth Israel Hospital. Co-author with science writer Douglas Colligan of The Healer Within (E.P. Dutton, $22.50), Locke, who teaches at Harvard Medical School, contends that outlook and attitude play an important role in influencing the course of disease. He discussed his findings with Assistant Editor David Grogan.

The New England Journal of Medicine recently declared that the "belief in disease as a direct reflection of mental state is largely folklore." You don't agree?

The medical establishment continues to underestimate the link between emotion and illness, ignoring a large body of research that has been done during the past 10 years. At the same time much of the public attaches itself too uncritically to every new fad that promises people can live longer, have more satisfying sex lives and be free of disease. Some things, like exercise and diet, are important health factors over which we do have some conscious control. But just thinking the right thoughts is no guarantee that we will avoid illness.

What is the most important factor in determining a person's health?

Probably genetic inheritance, which means we have to live with the cards we've been dealt. But stress studies of both animals and humans suggest that responding to the challenge of illness with a sense of helplessness can adversely affect the body's immune system. Much more research needs to be done, but it appears that a sense of hopefulness may be of value in optimizing the body's natural defenses against disease.

What is the evidence that stress and impairment of immunity are linked?

Some of the first concrete evidence came, literally, from outer space. During the Apollo flights of the '60s and '70s, NASA doctors noticed that many astronauts experienced a change in the number of their immune cells after the space missions. During the ill-fated Apollo 13 flight, an on-board explosion nearly marooned the crew permanently between the earth and the moon. Two of the three men developed infections. A possible explanation for this is that the potency of their immune systems was reduced, and this may have contributed to their susceptibility to infection.

What stresses are likely to affect people who aren't subjected to such high-risk situations?

For earthbound humans, a more common stressful situation occurs following the loss of a loved one. Many people believe that the death of a spouse is likely to be followed by illness in the surviving spouse. Common sense accounts for some of the reasons. Widows and widowers may overindulge in such unhealthy habits as smoking and drinking. They may use more tranquilizers or not eat sensibly. But one recent study of a group of men whose wives died of breast cancer revealed that their own immune systems also showed a sharp drop in responsiveness. Gradually their systems regained strength, but even a year later the natural defenses of some of these men had not rebounded completely. Although there was no absolute link between bereavement and the immune system, a cause-and-effect relationship was implied.

Why is it that some people seem better prepared to deal with stress, whether it is caused by a death in the family or simply the pressure of a boring job?

One factor that appears to be particularly significant is social support: close emotional ties with friends or family. Over a 10-year period, 2,700 people in a small Michigan town participated in elaborate psychological interviews, during which they were rated according to a personal-relationships scale. Factors noted were the number of a person's friends, his or her closeness to relatives, participation in group activities and the types of activities he chose to take part in. At the end of the study the people who led "lonely" lives had four times the mortality rate of those considered more social.

About 30 percent of Americans living today will eventually contract cancer. Are some people more prone to cancer because of their personality makeup?

Two recent studies suggest that depression as a trait in young adults may be a minor factor in increasing their susceptibility to cancer later in life. But it would be wrong for people, in an effort to guard against cancer, to put an inappropriate emphasis on how they handle their emotions. Personality traits are much less significant in this regard than things people knowingly do to their bodies—such as smoking and drinking excessively or following a diet rich in fat.

We have all heard inspirational stories about people who survive cancer, sometimes against seemingly overwhelming odds. Is mental attitude a factor in these cases?

Researchers disagree about the implications of what we know. But some clinical experiments suggest that long-term survivors of cancer are likely to be people who are open in expressing their emotions, free from depression, hopeful and characterized by a fighting spirit. One of the most revealing studies involved 57 breast cancer patients in London, whose emotional response to the disease after undergoing mastectomies was measured over a 10-year period. The researchers discovered that the patients who were categorized as having a kind of John Wayne attitude that "I can lick this thing" marshaled the strongest immune defenses against the disease and had the best chance of survival. On the other hand, the poorest overall survival rate was among those who reacted either with a stoic acceptance to their disease or with hopelessness.

Some therapists have been experimenting with the use of "mental imagery" to treat cancer patients. How does this technique work?

Patients are asked first to relax and then to imagine, in some symbolic manner, the immune system attacking the cancer. They are given suggestions that the cancer cells are weak and confused and that the body's white blood cells, which are the core of the immune system's natural defense against the disease, are powerful and aggressive. The specifics of the images depend on the patients' own ingenuity. For example, some envision the cancer cells as small, frightened fish and the white cells as voracious sharks.

Is this effective?

The evidence that imagery works to control cancer is limited. As yet there, is no scientific proof that it does or it doesn't. Since the technique of visualization is still entirely experimental, I feel strongly that people should not be charged money to be treated with it.

In desperation, some cancer patients might be willing to try anything, regardless of cost. Can a technique like visualization do any harm?

I had one patient with cancer who got involved in a program in which visualization was taught as a means of prolonging survival. When her disease progressed anyway, she was repeatedly criticized by other members of her therapy group for not believing strongly enough that the technique would work. They made her feel guilty for having a bad attitude. There is a downside to selling people a rationale that says, "If you think these thoughts and if you act this way, then you will fight your cancer more effectively." If the disease progresses, patients may blame themselves for failure. One could speculate that the mental distress caused by such feelings of guilt might then work against the patients' recovery. When a treatment is ineffective, a physician or any other healer has to be prepared to help patients deal with their disappointment and sometimes their anger.

What advice do you have for cancer patients who are seeking alternative therapies which stress positive thinking?

To begin with, they should be instantly suspicious of anybody who promises that the behavioral approach is going to prolong their lives or improve their chances of survival. Unfortunately there are many people in the field of holistic health who are not interested in whether something is scientifically proven or not. Those people are dangerous. On the other hand, many doctors are unwilling to entertain the idea that something new may have value. They may reject it without evaluating the evidence. They, too, are dangerous.

Whom should a patient consult before deciding on a course of action?

Ideally, patients should be able to bounce ideas off their regular physician and call upon his skill and judgment to help evaluate the effectiveness of a particular treatment. If that is not the case, they should get a second opinion and reevaluate the care they are getting. Research evidence justifies some cautious optimism that, in addition to biofeedback, exercise and relaxation techniques, such methods as hypnosis and imagery may be effective in enhancing immune functions. But we must not replace the science of medicine with an all-encompassing belief in a panacea—the cure to end all cures.