Effects of antidepressants on postmenopausal bone loss - A 5-year longitudinal study from the OSTPRE cohort

Osteoporosis and depression are major health problems worldwide. The association between antidepressants, a treatment for depression, and bone health needs more detailed exploration.

The present study investigates antidepressant medication use and postmenopausal bone loss over time.

A total of 1988 women (aged 57-67) participating in the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) cohort responded to a postal enquiry and had their femoral neck bone mineral density (BMD) measured in 1999 and again in 2004. Data on antidepressant use was obtained from the National Prescription Register. Multiple regression techniques were used to test the associations, before and after adjustment for anthropometric, medical, physical and lifestyle factors.

Over the five years of follow-up, 319 (16.0%) women purchased antidepressants. Mean baseline femoral neck BMD for the entire study group was 881mg/cm(2) (SD 123) and mean 5-year bone loss was 6.0mg/cm(2) (SD 4.7). After adjustments, users of tricyclic antidepressants (TCA) had greater annual BMD loss than non-users (-3.6mg/cm(2) vs. -1.1mg/cm(2); P=0.031). Accelerated bone loss was also associated with selective serotonin reuptake inhibitor's (SSRI) use (P=0.001) and use of other antidepressants in a dose-response way, with the latter only among women of low-weight and normal-weight women who had lost weight over the study period.

In conclusion, the use of SSRIs seems to accelerate postmenopausal bone loss in a dose-response manner. Associations between TCA and other antidepressant use and bone loss may also exist. Thus, the possibility of increased risk of osteoporosis should be considered when prescribing antidepressants for postmenopausal women.