Someone suffering from depression might experience bouts of insomnia, loss of appetite, and overall lethargy. It can also trigger less obvious problems.
Growing evidence suggests that depression, one of the most common diseases of the brain, is so powerful it can actually erode bones in the body.
Cindy Uhl, a lab technician in Rochester, Minn., was one of those people determined to stay healthy. She exercised regularly, ate well, and routinely took vitamin and mineral supplements. Then one day two years ago, walking to work, she slipped and fell. Her wrist was shattered.
"It looked like I had gone through a car windshield from the way the bones had been damaged," she said.
During the operation, doctors discovered why. Uhl had remarkably brittle bones. At only 46, she had advanced osteoporosis.
"Usually a woman that age can sustain a fall and put their wrist out and catch themselves and not have any problem," said her physician, Dr. Lorraine Fitzpatrick of the Mayo Clinic. "But she had this very bad fracture.
"Cindy had the bones that were the equivalent of someone who's 15 to 20 years older than she was," said Fitzpatrick.
One likely explanation, doctors said, was that Uhl had suffered from a bout of depression years earlier.
Dr. Philip Gold, chief of the Clinical Neuroendocrinology branch at the National Institute of Mental Health, is conducting pioneering research on the effects of depression on bone density.
"If you are a pre-menopausal woman and you've had major depression you have a 25 to 30 percent chance of having lost significant amounts of bone and are at much higher risk of fracture," said Gold.
"The general physician and people in the general population would be very surprised to find out there is such a significant risk of osteoporosis in patients with depression."
Brain Controls Hormones, Causing Bone Loss
Depression is like a severe and prolonged state of stress. It causes blood pressure and the heart rate to increase. It also causes the brain to produce dangerously high levels of hormones.
"The brain really controls the hormones in the bloodstream," explained Gold. "The brain speaks to the body through hormones, and that is how the brain induces bone loss and other medical problems in patients who are depressed."
And it doesn't take much. Research suggests a depression that lasts only a few months can trigger significant bone loss. There's preliminary evidence it can have the same effect in men.
"The men who are depressed really seem to lose bone even more rapidly and to a greater extent than the women," said Gold. But since bone density in men is greater to begin with, fewer men are likely to lose enough to have actual bone fractures.
Women at Higher Risk of Breaking Bones
For women, doctors say, the situation is much more alarming.
Researchers at the National Institutes of Health estimate that at least 400,000 women in the United States, women in their 30s and 40s, already have brittle bones as a result of depression and don't even know it.
"Depression is an under-recognized risk factor for osteoporosis," said Dr. Fitzpatrick of the Mayo Clinic. "It just doesn't seem to be on anyone's radar screen."
The good news, say doctors, is that osteoporosis can be easily diagnosed with bone mineral density scans, and readily treated with medications that not only stop bone loss, but actually grow new bone.