Multiple scientific studies have found a relationship between the use of antidepressants and increased risk of bone fractures. The science suggests that depression may be a causative factor in developing osteoporosis. However, treating depression minimizes the risk of brittle bones.
Major depression, or major depressive disorder, is an extremely common condition. In the United States, it affects about 16 percent of the population at some point in life. Major depression is characterized by anhedonia, being unable to enjoy life, or dysphoria, always being in a blue mood. People who have major depressive disorder may give up on life and simply retreat to bed. This form of depression also interferes with sleep and appetite.
There’s no doubt that osteoporosis is a depressing condition. The pain can be constant. Local governments may make it difficult to get effective pain medication. There can be fractures that cause permanent disability, but there can also be a fear of fracture that leads people simply to take to bed and retreat from life. The lonely lifestyle imposed by osteoporosis can be very similar to the lifestyle of someone who is depressed. People who are forced to spend a lot of time alone often get into situations in which falls and fractures are inevitable. But is there a more direct bone-brain connection?
In 1994, researchers compared bone mineral densities of two groups of women, one who had or currently suffered major depressive disorder, and another group of women who did not. The DEXA scans revealed that the women who suffered major depression had, on average, 15 percent lower bone density than the women who did not, when results were adjusted for age.
Not every study since 1994 has confirmed that major depressive disorder is associated with weaker bones. However, the long-term study that did not find statistically significant data confirming that depression is linked to brittle bones found that stress levels (measured by a hormone called cortisol) were linked to bone mineral depletion. There is a consensus of scientific finding that depression, over the long term, is often followed by weaker bones.
There is a happy caveat to these studies
The early studies of bone mineral density in depressed and non-depressed women kept the findings simple by excluding women who had received antidepressants. (They did not exclude women who had talk therapy.) When scientists conducted studies of osteoporosis in treated depression patients, here is is what they found:
- Using modern selective serotonin reuptake inhibitors (SSRIs) such as Prozac, Zoloft, and Paxil is associated with loss of bone mineral density. One study found that the average loss of bone mineralization after multi-year use of Prozac was just 4 percent. This relatively small amount of bone loss may not have much Impact on day to day life. The problem may be that users of SSRIs are more prone to lapses of attention or have balance problems that lead to falls and fractures. (There are studies with laboratory mice that found that giving Prozac by IV increased bone mineralization, but these may not be generalizable to humans.)
- Using older-style tricyclic antidepressants is not associated with a loss of bone minerals.
- Using phosphodiesterase antidepressants (available in the UK and many countries in Europe but not North America) is associated with increased bone mineral density.
Current use of antidepressants is a stronger predictor of falls and fractures than past use of antidepressants. The risk of falls is much more immediate than the risk of osteoporosis when it comes to antidepressant use. Using SSRIs for 10, 15, 20, or more years may adversely impact bone. If it is necessary to use the drugs, then the sensible thing to do is to get an evaluation by a doctor for early osteoporosis before fractures happen.
Five take-aways from studies of osteoporosis and depression
The practical implications of 25 years of research into the relationship of bone health and mental health can be boiled down to these five recommendations:
- If you are ever diagnosed with major depression, follow through with an evaluation for osteoporosis. Early diagnosis can enable lifestyle changes and medical treatment that prevent broken bones. This is especially important if you have been taking a SSRI for more than two years.
- If you live in a country where phosphodiesterase antidepressants are available, ask your mental health provider about taking them instead of SSRIs.
- Fall-proofing your home is important for people who have depression, just as it is for people who have osteoporosis.
- Don’t oversimplify bone health. Taking a calcium supplement with your Prozac won’t really do any good. Osteoporosis is a multifaceted condition and osteoporosis prevention and treatment is a multi-step process.
- Staying active is important in both osteoporosis and major depression. Continuing to interact with people and spending time outside the home are essential to maintaining mental and physical health in both conditions.