Women who suffer from depression tend to have weaker bones that are more likely to break than those of their nondepressed counterparts, according to a pilot study published in the 17 October New England Journal of Medicine.
The small study compared 24 women suffering from depression or with a history of the condition to 24 control women. The team, led by David Michelson, a medical researcher at Eli Lilly and Co. in Indianapolis, found that women with depression had hip bone mineral densities 10% to 14% lower for their age than those of controls. The bone loss increased their predicted risk of a fracture by 40%.
Study authors say they don't know what biochemical change associated with depression might lead to bone loss. Women with depression "could be prone to something that occurs with other conditions as well," says Michelson, who carried out the study while at the National Institute of Mental Health. Larger studies of bone loss over time could clarify that link. "We're just at the tip of bone research," adds Dana Seely, an epidemiologist at the University of California, San Francisco. "There could be many similarities between bone loss and biochemical [causes] that we don't know about."
The results don't mean that women with depression should start demanding bone-density screenings, Michelson says, "primarily because it's not clear what [physicians] should do with that information." For older women, however, the findings support the value of estrogen-replacement therapy. Estrogen given to postmenopausal women not only slows bone loss, says Seely, but as a bonus it elevates mood.