Depression Can Hurt, Right Down to Your Bones

Beauty might be only skin-deep but, according to a new study, depression can seep straight to the bone.

New research from Hebrew University, published in the journal Proceedings of the National Academy of Sciences, found a link between depression and bone density, among the leading causes of osteoporosis and bone fractures, particularly in post-menopausal women with winnowing levels of estrogen.

And as older folks know, a rickety skeleton is no laughing matter. Some 10 million Americans over 50 have brittle bones, while another 35 million are at risk. Hip fractures already account for 300,000 hospitalizations a year, according to the Department of

Health and Human Services, and cost some $18 billion each year.

The research team found that sad-sack mice -- induced into a depressed state so they, like their clinically depressed human counterparts, avoided social interaction, sex, and generally sought less pleasure in life -- dramatically lost bone density in their hips and vertebrae after just four weeks, some by as much as 14 to 17 percent over three experiments.

The loss, the researchers hypothesized, was caused by impairment in the bone-renewal process and the loss of cells -- called osteoblasts -- responsible for bone-building.

The connection, the researchers said, lies in the link between the brain and the body's organs, called the sympathetic nervous system, and the activation of noradrenaline within the bone, a chemical our bodies produce while under stress that grinds down bones.

Of course it's long been known than stress in life -- like depression -- can have some pretty nasty side effects, but the Hebrew University study is the first time a link between bone density and emotional disturbances has been cemented.

"Our results constitute important and convincing demonstrations for the interconnections between mind and body," said Raz Yirmiya, a professor of psychobiology, in an e-mail from Jerusalem. "Establishing a link among depression, excessive sympathetic activation and impaired skeletal structure is of key importance because these conditions characterize menopause and aging,"

The researchers also found that using the anti-depressant imipramine -- sold in this country as Tofranil -- helped stave off not only the blues but also brittle bones. There's even evidence, said Yirmiya, that the common anti-depressant Prozac also builds bone mass, though it's still too early to recommend antidepressant treatment for brittle-boned patients without depressive symptoms. He's studying that next, he said.

So does this mean those on common antidepressants can nix the calcium supplements and chuck the cottage cheese?

While Yirmiya said it's likely that post-menopausal women might be off the hook if they're already on antidepressants, others, like Lowell General Hospital and Saints Medical Center bone doctor Lawrence Johnson, called that conclusion rickety.

"The research is promising, but preliminary," Johnson said. "Certainly I think there is a connection between osteoporosis and depression in that when you're depressed you don't exercise as much as when you're not, and that leads to weaker bones.

"But until we have larger, human models, I'd say, keep taking your supplements and do some exercising, which, of course, can help with depression as well. These are results in mice. They've got a way to go here."

(Copyright (c) 2006, The Sun, Lowell, Mass. Distributed by McClatchy-Tribune Business News.)

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