We’ve all heard the phrase “it’s all in your head.” But new scientific research may be proving it has more truth in it than we ever imagined. The evidence points to a very real correlation between the mind and the body.

“More and more doctors—and patients—recognize that mental states and physical well-being are intimately connected,” wrote Michael D. Lemonick in How Your Mind Can Heal Your Body. “An unhealthy body can lead to an unhealthy mind, and an illness of the mind can trigger or worsen diseases in the body. Fixing a problem in one place, moreover, can often help the other.”

Depression is proving to be particularly destructive to physical health. “Depression jumps out as an independent risk factor for heart disease,” reports Dwight Evans, a professor of psychiatry, medicine, and neuroscience at the University of Pennsylvania. “It may be as bad as cholesterol.”

Heart disease isn’t the only illness worsened by depression. Those who suffer from cancer, diabetes, epilepsy, and osteoporosis all appear to “run a higher risk of disability or premature death when they are clinically depressed.”

In fact, 10 percent of diabetic men and 20 percent of diabetic women also have depression—a rate double that of the general population. Depressed diabetic patients were far more likely to have complications, including heart disease, nerve damage, and blindness.

According to studies by Philip Gold and Giovanni Cizza at the National Institute of Mental Health, depressed premenopausal women exhibit a much higher rate of bone loss than those who aren’t depressed. An estimated 350,000 women get osteoporosis each year because of depression, says Cizza. Various studies have tied depression to several other diseases, including cancer, Parkinson’s disease, epilepsy, stroke, and Alzheimer’s.

Just as depression can paralyze our outlook, so can negative emotions such as anger and fear. A fascinating Duke University study called “Anger Kills” examined the profile of physicians in medical school to determine their anger scale. (In this case, anger wasn’t simply being upset at a particular incident—that can happen to anyone. Anger here meant a life orientation, the explosive personality that resents everything. Those physicians high in the anger scale had a greater incidence of heart disease 25 years later.)

Following the September 11, 2001, attacks on the World Trade Center, Jonathan Steinberg, chief of cardiology at New York’s St. Luke’s-Roosevelt Hospital Center, led a study on New York City’s heart patients (see “Our Bodies, Our Fears,” Newsweek, Feb. 24, 2003). He found that they suffered twice the usual rate of life-threatening heart arrhythmias in the months following the attacks.

“Prolonged stress has physiological consequences,” Steinberg observes. “These patients experienced potentially fatal events, even though many of them had trouble identifying themselves as unduly fearful.”

“The psychological state of fear affects us biologically,” said Los Angeles psychiatrist Carole Liberman. “People who are anxious drink and eat more. They have more accidents. They’re more likely to get colds or suffer heart attacks.”

“Stress,” adds Afton Hassett, an expert in psychosomatic illness, “almost always comes out in a bodily symptom.”

For help managing stress or depression, check out the CREATION Health Bible Program.