Chronic Depression May Steal Your Happiness and Health

Third Age Health & Wellness

Chronic Depression May Steal Your Happiness and Health

Bryce Miller’s work as an industrial engineer in Topeka, Kan., wasn’t a whole lot more challenging than the job he faces in retirement: engineering his own medical care by 10 different doctors. Miller, 74, sees a team of specialists, which includes a cardiologist, a urologist and radiologist for prostate cancer, an endocrinologist for diabetes, a nephrologist for kidney problems, and a psychiatrist to manage the severe episodes of depression he has suffered during a long struggle with bipolar disorder. “I can’t find a doctor who can handle all of it,” he says.

It’s impossible to pinpoint all the causes of Miller’s illness; a combination of bad genes, bad luck and bad diet probably gets much of the blame. But lately, he says, he’s been wondering whether his mental state may have played a role, too. Medicine has recognized for some time that chronically sick people are prone to depression and that those affected have a tougher road back. Now, the signs are mounting that the spectrum of depressive illness, and perhaps even bitter loneliness, may actually make healthy people more vulnerable to a range of physical ailments.

“There is a growing body of evidence suggesting that depression might be a causal risk factor in diseases like ischemic heart disease, stroke, diabetes, and immune-based diseases like cancer and HIV/AIDS,” says Dwight Evans, chair of psychiatry at the University of Pennsylvania medical school (Philadelphia). “And there is also considerable recent evidence that mood disorders can affect the course of medical illnesses. It goes both ways. Depression may be both a cause and a consequence of medical illness.”

Risk Factor
Consider a study published in March in the journal Diabetologia, which concluded that depressed adults have a 37 percent greater risk of developing type 2 diabetes than the rest of the population; other studies have suggested their risk actually doubles. (Apparently, English physician Thomas Willis was on to something when he wrote in 1674, “Diabetes is caused by melancholy.”) One intriguing recent study of Alzheimer’s patients revealed that those with a history of depression had more extensive plaques in their brains. Depressed postmenopausal women with no history of heart disease are much more likely to develop it and die of it than their peers. In March, researchers at the University of Chicago (Chicago, Illinois) showed that loneliness can spike blood pressure by 30 points in older people. Pancreatic cancer, for reasons scientists don’t understand, is often preceded by a serious depression before the disease asserts itself.

And when melancholy comes on the heels of disease, it appears to compound the physical insult. Diabetes is more likely to be uncontrolled, for example. And several studies have found that in the months right after a heart attack, the depressed patients are much more likely to die than the others.

If the researchers are right, the human cost of letting depression go untreated is staggering. Nearly 25 percent of American women and 10 percent of men will be clinically depressed at some point in their lives; a massive study conducted by the World Health Organization, Harvard University School of Public Health and the World Bank found that by 2020, depression will be second only to heart disease as a cause of medical and physical disability. People who have suffered silently because their mental-health insurance benefits are so stingy got a glimmer of hope recently from the results of a large study showing that employers could beef up benefits without significantly raising costs.

What might explain the mind’s influence on physical health? Certainly, chronic depression does not encourage a healthy lifestyle. “Depressed individuals don’t exercise. They are more likely not to take medication, and it is harder for them to lose weight and stop smoking,” says Nancy Frasure-Smith, a professor of psychiatry at the University of Montreal and McGill University (both in Canada) who has long studied the link between depression and cardiovascular disease.

The Biochemistry
But depression also acts on the body’s systems in ways scientists are only beginning to understand. Extra stress hormones are produced, for example, along with chemicals that trigger inflammation. When the hormone cortisol is secreted in response to stress, the body’s blood glucose level rises to provide a burst of energy. A depressed brain’s constant signal that it’s under stress and needs more energy complicates the body’s regulation of blood sugar. Might this explain why depression seems to both trigger and exacerbate diabetes?

Next: Depressed people and cardiovascular disease >Read More…

A stress response may set depressed people up for cardiovascular disease, too — or aggravate it. When the blood-clotting system gets ready for impending injury, sticky cells called platelets go on high alert to slow down bleeding. In depressed people, one study showed, the platelets are more apt to be in this state of readiness. The problem: Clotting is what causes heart attacks and strokes. Chemicals called cytokines flood the bloodstream, as well. These messengers from the immune system cause inflammation, which makes blood vessels thicken and artery-hardening plaques form.

Researchers have also noted another stress reaction: The heart muscles of depressed patients lose flexibility. A normal heart transitions easily between its resting and beating states; more rigid muscle is less able to respond to the changing demands of the body for blood and oxygen. A study published in March in the Journal of the American College of Cardiology found that mental stress caused a more dramatic decrease in blood flow to the heart muscle — or ischemia — than a stress test on a treadmill. All told, stress and depression probably explain “close to 30 percent of the total risk of heart attacks,” estimates David Sheps, professor of medicine and associate chief of cardiovascular medicine at the University of Florida, Gainesville.

It’s way too soon to make the leap that depression is a direct cause of heart disease akin to smoking or high cholesterol, or that treatment — like quitting cigarettes — can reverse the damage or save lives. Indeed, two big recent studies have failed to show that heart patients live longer when they undergo therapy or take antidepressants. But medicine is intent upon dealing with the mental health of cardiac patients anyway, because people who are not depressed are more likely to lead heart-healthy lives; they exercise, take their medicines, lose weight and stop smoking.

“If you are a patient with heart disease, you need to know what your cholesterol level is, what your blood pressure is, and what diet and exercise program you will need to prevent a second heart attack. You should add to that list whether or not you are depressed,” says Richard Stein, director of preventive cardiology at Beth Israel hospital in New York City.

The majority of people who’ve survived some sort of heart event are, at least for a while. Some 65 percent of heart attack survivors are estimated to fall into depression, for example. According to Mended Hearts, the oldest and largest support group for people with heart disease, about 70 percent of patients who have gone through heart surgery, which often follows a heart attack, get depressed during the first year, and about a third continue to suffer from debilitating depression.

“I was just inside this ugly tunnel,” says Dale Briggs, a Mended Hearts executive and an insurance fraud investigator from Fresno, Calif., who had a valve replaced in his heart 12 years ago at age 48 and was overwhelmed by the emotional consequences. He couldn’t sleep, watched television for hours on end, and found it impossible to exercise or eat properly until his doctor prescribed medication and his depression lifted.

Brain Drain
The research linking depression to dementia is still in its infancy and has raised more questions than it has answered. One study published in February, by researchers at the University of Pittsburgh (Penn.), found that adults with symptoms of depression scored a bit lower on cognitive tests than those who were not depressed, a finding consistent with extensive previous research on the way depression contributes to cognitive impairment. But only about 13 percent of the patients who eventually developed dementia were depressed.

At the same time, though, another group of researchers reported that the brains of Alzheimer’s patients with a history of depression had more of the disease’s characteristic tangles and plaques in the hippocampus — the area largely responsible for memory — than those of other patients. Moreover, their medical records indicated that they’d succumbed more rapidly to the ravages of the illness. “About all we do know with certainty,” says Michael Rapp, a resident at Mount Sinai medical school (New York City) and one of the authors of the Alzheimer’s study, “is that the biggest risk factor for Alzheimer’s disease is old age.”

What also seems certain, however mysterious all these connections may be, is that mental health can no longer be considered a separate issue. Realizing that there may be links between his mental and physical illness has brought Bryce Miller some peace with a body that has often confused him. “When they stuck my finger 15 years ago and found out that I was diabetic, it never occurred to me that my depression had something to do with it,” he says. “But now it just seems so clear: The brain is always connected to the body.”

Source: Marianne Szegedy-Maszak

  2006, U.S. News and World Report. L.P. Distributed by Tribune Media Services.

Reviewed by Forum Admin 02-07-2010

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