Depression and osteoporosis: epidemiology and potential mediating pathways.

INTRODUCTION: There have been numerous studies examining the association between depression and bone mineral density (BMD), but the underlying nature of this relationship remains unclear. Independent of this association, there is a growing body of evidence that depression impacts the risk for fracture in older adults. This article reviews the current epidemiological evidence regarding comorbidity of depression, low bone mineral density, and fracture.
METHODS: A review of the literature on depression, depressive symptoms, low BMD, osteoporosis, and fracture using electronic databases.
RESULTS: We reviewed 20 studies of the association between depression and BMD and five reports of the relationship between depression and fractures. Potential mediating mechanisms (both physiological and behavioral) are discussed, as well as potential confounding influences (e.g., medication use).
CONCLUSIONS: Most studies support the finding that depression is associated with increased risk for both low BMD and fractures, but variation in study design, sample composition, and exposure measurement make comparisons across studies difficult. Researchers should be aware of potential confounders, such as medication use, that may influence results. Future research should focus on identifying mediating pathways and targets for intervention in the relationships between depression, low BMD, and fracture.