Study Shows Connection Between Depression and Bone Loss
Scientists from the Hebrew University of Jerusalem have assessed data from 23 research projects involving over 23,000 participants in eight countries and have found a clear connection between depression and a loss of bone mass, which can lead to osteoporosis and fractures. The association is particularly strong among young women.
The results, published in the journal Biological Psychiatry, found that depressed individuals have an increased activity of osteoclasts (cells that break down bone) which leads to a substantially lower bone density. The current research expands on studies that the researchers conducted in 2006 that found the same correlation in laboratory mice.
A state of depression sets off the sympathetic nervous system that connects the brain to the internal organs and the skeletal bones. Activation of the SNS causes the secretion of the chemical noradrenaline, which has a detrimental effect on bone-building cells. The development of medications to block noradrenaline within the bone can lead to new drugs for the treatment of osteoporosis.
Unfortunately, it appears that some anti-depressant medications may further increase bone loss. A June 2007 issue of the Harvard Women’s Health Watch reported that women over the age of 50 who regularly took selective serotonin reuptake inhibitors (SSRI’s) had double the rate of fractures as people not taking the anti-depressant, however it isn’t clear if the depression or the medication was the actual cause of the decrease in bone density. Some research has found that a different class of medication, called tricyclic antidepressants, reversed both depression and the depression-induced bone loss.
A study by the National Institute of Mental Health is also evaluating the role that the stress hormone cortisol may play in the lowering of bone mass.
Other factors that are likely involved in the connection between depression and osteoporosis include poor dietary habits involving either reduced appetite and weight loss that can lead to bone density reduction or weight gain by overeating, usually “junk” or “comfort” foods that may be low in important bone minerals such as calcium and magnesium. Depressed individuals also experience a decrease in energy and social isolation that would likely deter them from participating in bone-building exercise. Excess alcohol, tobacco, or drug use can also lead to the loss of bone mass.
Osteoporosis is a common degenerative disease, afflicting 1 in 3 women and 1 in 5 men over the age of 50. Depression affects 5 to 9% of women and 1 to 2% of men, according to the NIMH.