article how mind change body

How Your Mind Can Heal Your Body

Mind | Body | Depression | The Power of Mood

Special Issue Time Magazine - 2003 January 20

by Michael D. Lemon

New ways to beat The Blues

The link between Mental and Physical Health

Is Happiness in your genes?

Women, Men and Depression

Lifting your spirits can be potent medicine. How to make it work for you.

Bill Valvo could sense that something was going very wrong with his health. He had worked for a software development company in Fairfax, Virginia for 10 years following a 22-year hitch with the Air Force, and the pressure was finally too much. "I left to start my own business," says Valvo, now 55, "but I could feel that all the stress was having physiological effects." Sure enough, he was diagnosed with coronary-artery disease and underwent bypass surgery in 1999. But after the operation, he spiraled into a severe depression, which would recede and then return with renewed force. Finally, Valvo's physician put him on an antidepressant - which not only relieved the depression, but also made him a convert to a new way of thinking about illness and health. "Did my heart operation cause the depression I'm experiencing?" he wrote recently in an article for a newsletter for a chapter of Mended Hearts, a support group for heart patients and their families. "Does depression cause heart disease? The answer to both those questions is probably "yes."

A few years ago, doctors would have dismissed Valvo as a New Age crank. But these days he is solidly in the medical mainstream.

More and more doctors - and patients - recognize that mental states and physical well-being are intimately connected. 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.

The brain, after all, is only another organ, and it operates on the same biochemical principles as the thyroid or the spleen. What we experience as feelings, good or bad, are at the cellular level no more than a complex interaction of chemicals and electrical activity. Depression represents an imbalance in that interaction, one that can kill just as directly as more obviously physical ailments. Each year in the U.S., an estimated 30,000 people commit suicide, with the vast majority of cases attributable to depression. But depression's physical toll goes far beyond the number of people who take their own life and even beyond the impact on depressed people's relationships and productivity (which costs the U.S. economy some $50 billion a year).

The pathology of depression shows with especial clarity that mind and body aren't separate at all; they are part of a single system. In the case of depression, this interconnection takes the insidious form of making other serious diseases dramatically worse. Once you have had a heart attack, for example, your risk of dying from cardiovascular disease is four to six times greater if you also suffer from depression.

It's not just that people tend to be depressed because they have a life-threatening illness or that depressed people smoke, are too lethargic to take their medicine or aren't motivated to eat right or exercise. "Even when we take those factors into consideration," says Dr. Dwight Evans, a professor of psychiatry, medicine and neuroscience at the University of Pennsylvania, "depression jumps out as an independent risk factor for heart disease. It may be as bad as cholesterol."

Heart disease is one of a long list of illnesses that worsen with depression. People with such afflictions as cancer, diabetes, epilepsy and osteoporosis all appear to run a higher risk of disability or premature death when they are clinically depressed. The effect is potentially so significant that the medical profession has begun to focus serious attention and resources on trying to understand what's going on. At a national conference in Washington in November, Evans served as co-chairman of a meeting, sponsored by the nonprofit Depression and Bipolar Support Alliance (DBSA), to get a better handle on how widespread the problem is. For two days, experts in cancer, AIDS, heart disease, diabetes and other diseases, along with patient advocates, listened to the evidence linking depression with one illness after another.

Fortunately, scientists have made great strides in sorting out the underlying causes of depression: it is almost certainly a defect in some combination of key genes, plus the right triggering environment. And researchers are well along in developing some promising therapies, pharmacological and otherwise, to supplement what is already available. But while the disease-depression connection is becoming more and more clear, how to uncouple them is an uncharted process. "You would think that treatment would alter the negative relationship between depression and other illness," says Dr. Dennis Charney, head of mood- and anxiety- disorders research at the National Institute of Mental Health (NIMH). But, he adds with proper scientific caution, "we don't have proof of that yet."

The idea that treating depression might lessen the severity of other diseases, though, makes basic biochemical sense. Everyday experience makes it clear that brain chemistry governs more than just the emotions. When your mind feels terror, the resulting surge of adrenaline makes your stomach churn. When your mind is sexually aroused, the body responds in unmistakable fashion. The effect is even more direct with the 60 or so chemicals known as neurotransmitters, which signal one cell that its neighbor has just sparked and that it should pass along the message. Brain chemicals such as serotonin circulate everywhere, not only in the brain. "Depression really is a systemic disorder," says Evans, "and many of the neurotransmitters that we believe are involved in the patho-physiology of depression have effects throughout the body."

Precisely how these powerful chemicals affect the course of heart disease, cancer and other illnesses isn't well understood yet, but preliminary research has yielded some tantalizing clues. When serotonin circulates in the bloodstream, for example, it appears to make platelets less sticky and thus less likely to clump together in artery-blocking blood clots. For years, heart-attack survivors have been advised to take a children's aspirin daily for clot prevention; such drugs as Prozac, which keep serotonin in circulation, seem to have a similar effect.

Another mechanism may also be at work. It turns out that the heartbeat of a person with depression is unusually steady. That's not necessarily a good thing, says Charney, who co-chaired the DBSA conference. "Ideally, your heart rate should be variable - it means your heart can respond appropriately to the different tasks it's called upon to respond to." Yet another possible link between heart disease and depression is a chemical called C-reactive protein (CRP). The liver normally produces CRP in response to an immune-system alarm when the body is infected or injured, and CRP is associated with the inflammation that results. For reasons still unknown, though, a recent study of depressed individuals found elevated levels of CRP. And in patients whose arteries have been damaged by the buildup of cholesterol plaques, heightened inflammation may increase the chance that a bit of plaque will break off and shut down an artery.

Diabetes is another illness that doesn't go well with depression. It's well known that 10% of diabetic men and 20% of diabetic women also have depression - about twice the rate in the general population. It's natural to be depressed about having a chronic, potentially fatal illness, but that doesn't entirely explain the discrepancy. Moreover, depressed diabetics are much more likely than those without depression to suffer complications including heart disease, nerve damage and blindness. Somehow depression makes the body less responsive to insulin, the hormone that processes blood sugar - plausibly through the action of cortisol, a hormone that can interfere with insulin sensitivity and that is often elevated in depressed patients.

Cortisol may also make depressed patients more prone to osteoporosis. Studies by Dr. Philip Gold and Dr. Giovanni Cizza at the NIMH have shown that pre-menopausal women who are depressed have a much higher rate of bone loss than their non-depressed counterparts - and this disparity increases as women pass through menopause. Indeed, Cizza estimates that some 350,000 women get osteoporosis each year because of depression. Cortisol appears to interfere with the ability of the bones to absorb calcium and offset the natural calcium loss that comes with menopause and aging. Another class of chemicals, the pro-inflammatory cytokines, have also been implicated in osteoporosis and diabetes, but their role is less clear.

Studies have established links between the incidence of depression and several other diseases, including cancer, Parkinson's disease, epilepsy, stroke and Alzheimer's. In some cases at least, researchers have clues, if not definitive evidence, as to which molecules might be involved. In Parkinson's the problem is the death of cells in the brain that produce the neurotransmitter dopamine. While dopamine is crucial to the control of movement, it's probably a major factor in mood as well. "Depression almost certainly has multiple causes that produce similar symptoms," observes Dr. Bruce Cohen, president of McLean Hospital in Belmont, Massachusetts.

That could explain why drugs that improve serotonin chemistry don't always work on depression - and why Parkinson's and depression can feed on each another. Epilepsy, stroke and Alzheimer's which, like Parkinson's, involve physical alteration of the brain, probably also affect that organ's ability to make or process neurotransmitters - not only serotonin and dopamine, but also glutamate and norepinephrine, all of which may be involved in different forms of depression.

Most treatments for depression aim to restore the electrochemical imbalance that leads a depressed brain into warped thinking. The so-called tricyclic antidepressant drugs popular in the 1960's for example, boosted the activity of the neurotransmitters serotonin and norepinephrine, and two other neurotransmitters, active throughout the body. That often relieved depression but caused side effects, including overwhelming sleepiness, blurred vision and dizziness. The drugs also proved potentially lethal when taken in overdose.

Then in the 1970's, neuropharmacologists realized that they could minimize side effects by focusing just on serotonin. Antidepressant drugs like Prozac, Paxil and Zoloft, known as selective serotonin reuptake inhibitors, or SSRIs, were developed to keep serotonin from being reabsorbed quickly into nerve cells when it is produced.

Meanwhile, electroconvulsive therapy (ECT), better known as shock treatment, resets the electrical state of the brain by inducing a seizure. (Despite ECT's lurid reputation, it involves mild doses of current and can be almost miraculously successful in patients whose depression will not yield to drugs.) Even old-fashioned, low-tech talk therapy can help adjust a patient's brain chemistry and lessen the severity of depression, especially in conjunction with other treatments.

Unfortunately, the research that may unravel the interplay between depression and other diseases has barely begun. Even though there is a strong statistical link between depression and epilepsy, for example, we know very little about how to treat depression in epileptics. And as Charney has noted, it hasn't been proved, in a rigorous, scientific sense, that treating depression will reduce the excess risks of complication or death from a coexisting illness.

But if depression treatments rebalance the biochemistry that worsens disease, there is every reason to expect that they will reduce its deadly impact. So Charney, Evans and other experts want to make physicians more aware of the intimate connection between depression and other illnesses. "When you only have roughly eight minutes with your primary doctor," says Lydia Lewis, president of the Depression and Bipolar Support Alliance, "it's kind of hard to get into the realm of depression. And when you go to see a specialist, the cardiologist is thinking just about your heart."

So while researchers hold conferences, do studies and write scholarly papers, Lewis has some more immediate advice for patients. "We need to get people to go in and ask these questions of their physicians. Bill Valvo could not agree more. "I think people are totally unaware of what's going on," he says, "and I'm convinced that education is a key part of what we need to be doing." The essence of that education: cure the mind, and you might just help save the body. -- Reported by David Bjerklie/New York