Blood Inflammatory Proteins and Risk of Incident Depression in the Elderly

Abstract

BACKGROUND: It is unclear whether high levels of blood inflammatory proteins are associated with the risk of developing depression in late life. METHODS: Blood C-reactive protein, interleukin (IL)-6, 1 -antichymotrypsin (ACT), intercellular adhesion molecule 1, and tumor necrosis factor were measured in an elderly cohort (n = 968). Major depression diagnosed according to clinical criteria and relevant depressive symptoms measured by the Geriatric Depression Scale (score 6 10) were assessed at baseline and 4 year later. RESULTS: Baseline IL-6 and ACT were increased in both prevalent major depression and relevant depressive symptoms. Baseline ACT was increased in incident major depression. All associations weakened below significance after adjustment for possible confounders and multiple comparisons. CONCLUSIONS: Blood inflammatory proteins do not predict the risk of developing depression in older age.