Everyone has heard the story of the cancer patient who was cured through "positive thinking." Or, alternatively, how divorce, widowhood or job loss brought on sudden, severe illness.

Is there a scientific basis for these observations? Does one's mental state affect physical health, and vice versa?A flurry of new findings supports the link between the mind and body. Although the folklore has existed for years, technical advances now permit the measurement, purification and analysis of brain-body chemicals.

The brain and the body's immune system are inseparable - and they communicate back and forth in both directions, according to research by Dr. George F. Solomon of the University of California-Los Angeles reported in the Journal of the National Cancer Institute.

"The implication . . . for the practice of medicine is that patient attitudes and relationships with the physician may be as critical as the specific treatments themselves," said Solomon.

Intuitively, it has been long suspected that emotions, attitudes and coping mechanisms affect disease.

This phenomenon is seen most clearly in the so-called "placebo effect." When an individual believes that he has been given medication, the body actually responds positively. Even though the pills are chemically inactive, they may help people recover. It is not the remedy itself but a belief in the remedy that causes the person to mobilize some very powerful self-healing mechanisms within the body.

It is well-accepted that stress weakens the immune system - explaining why students tend to have more colds and skin infections during and after final exams.

But until recently, the scientific record for this new field, called psychoneuroimmunology, was spotty. One study would show a relationship between body and brain; the next would dispute it.

- A NUMBER OF EMERGING STUDIES show a strong, provocative link between personality and disease.

- Solomon's work suggests that personality factors seem to predispose an individual to autoimmune diseases (diseases in which the body attacks its own system), such as rheumatoid arthritis. Women with this disease show more masochism, self-sacrifice, denial of hostility, compliance-subservience, depression and sensitivity to anger than their healthier colleagues.

There is not an "autoimmune-prone," "cancer-prone," or "infection-prone" personality, he explains, but there does seem to be a broader, "immunosuppression-prone" personality.

- Dr. Wylie Vale of the Salk Institute for Biological Studies in San Diego is now studying the hormone that gives us the ability to respond to challenge. When the body is stressed, it releases corticotropin, or adrenocorticotrophic hormone (ACTH). This hormone prompts the release of a second hormone called cortisol, which converts protein to energy, boosts blood pressure and sets off other biological alarm bells.

His team is now designing an agent that blocks cortisol's effects, an agent that some day could be used to treat disorders like anorexia nervosa, depression and other behavioral disorders thought to be caused by imba-lanced brain chemistry.

- The "stress hormone" ACTH also triggers the release of norepinephrine from the nervous system, which appears to reduce the ability of natural killer cells to destroy cancer cells and other life-threatening infections, according to 1988 work by Dr. Michael Irwin of University of California-San Diego.

When the body is stressed, the increased production of "stress hormones" compromises the immune system, say scientists.

- In 1989, a Stanford University study of 86 Santa Clara Valley women with metastatic breast cancer showed that intensive group therapy and instruction in pain control added a year and a half to their lives.

All women were given a battery of tests at four-month intervals to assess moods, coping styles, family environments, degrees of pain and fear. Nine years later, all but three had died, as expected. But women in the treatment group lived an average of 18 months longer than women in the control group. The personality differences didn't make the cancer go away - they extended survival, doctors said.

- Traits that typify the neurotic person - chronic anxiety, long periods of sadness and pessimism, unremitting tension and hostility - are associated with asthma, headaches, peptic ulcers and heart disease, according to a study by Howard Friedman and Stephanie Booth-Kewly at University of California-Riverside, published in The American Psychologist. Their data suggest that neurosis makes a person twice as likely to contract some kind of illness.

A similar study by Christopher Peterson of the University of Michigan on members of the Harvard University classes of 1939 through 1944 found that men who were most pessimistic or fatalistic as students were more susceptible to disease of all kinds in later life.

- The newest piece of evidence, presented by Drs. Dana H. Bovgjerg and William H. Redd of Memorial Sloan-Kettering Cancer Center in New York, suggests that chemotherapy patients develop suppressed immune systems after repeated visits to the hospital for treatment. Blood samples showed that women who underwent repeated infusion of cancer drugs at the hospital suffered from decreased activity of an important type of immune system cells, as compared to women who received therapy at home.

(The conclusions are limited, however, because they were not compared to a control group of non-cancer patients. The changes in immune function could be a normal response to going to the hospital, or just to being more active. Furthermore, it is not yet demonstrated that these changes have any impact on survival.)

Yogis can train themselves so that they reduce their perception of pain. So can pregnant women in labor.

"Somehow, they set pain thresholds," writes Candace B. Pert, of the Section of Brain Chemistry, National Institutes of Health in Bethesda, Md., in a paper published by the Institute for the Advancement of Health.

"A person has an experience that brings with it pain, but a part of the person consciously does something so that the pain is not felt. . . . Where is this consciousness coming from?" she asks.

Experiments on patients by Dr. Jon Levine at University of California-San Francisco after wisdom tooth extraction suggest that neurotransmitters called endorphins "turn on" the pain regulation system. Earlier research found that endorphins appear to align with receptors on immune system cells called lymphocytes, suggesting a link between the brain and the immune system.

"The need now is to focus on specific aspects of the field, from the underlying molecular biological mechanisms that mediate between the central nervous system and the immune system to the behavioral correlates," Levine said.

"Clinically, we can expect important developments in the prevention and treatment of disease to emerge for the further exploration of psychoneuroimmunology."

- DOCTORS CONTINUE TO WARN against the belief that positive thinking alone can cure or stave off disease. Psychotherapy, for instance, should never be viewed as a substitute for standard treatments, they say.

Many studies are too quick to credit the psychological factors, dismissing the physiological factors that could cure disease, according to Dr. Robert Fine of Duke University.

The mind-body connection can be taken too far; sick people need not be blamed for their failure to get well or feel personally responsible for their sickness, doctors agree. At best, attitude is just one of many factors influencing disease outcome.

"I've seen the most positive, optimistic patient die rapidly and seen the most depressed pessimistic patients live on and on. . . . Life is not black and white," said Dr. Charles Moertel of Mayo Clinic in the Journal of the National Cancer Institute. When he studied factors that might prolong life - such as positive thinking, religious beliefs and nutrition - only nutrition seemed consistently to stave off cancer recurrence.

It is too soon to jump to conclusions, warned Dr. Mace Rothenberg of the National Cancer Institute's Division of Cancer Treatment in the NCI Journal. It is one thing to demonstrate an impact of emotional or psychological status on lab measures of immune response. It is much tougher to show that these alterations have any impact on the development or survival from disease, he said.

Too many people, he said, "are assuming that we have answered the second question when we have only begun to address the first."

Distributed by Scripps Howard News Service