Abstract
BACKGROUND: Underlying inflammation is associated with an increased risk of depression in older adults. In this study, we examined the role of inflammatory biomarkers in antidepressant response in depressed older adults undergoing adjunct Tai Chi Chih (TCC) or Health education interventions. METHODS: Older adults aged 60 years and above with a diagnosis of major depression were randomized to 12 weeks of TCC versus Health and Wellness Education (HEW) as an adjunct therapy to their stable antidepressant treatment regimen. A panel of 19 cytokine/chemokines was measured at baseline and 12 weeks. Five factors were derived using factor analysis. General linear models were estimated to examine the change in factor scores and the association of these changes on depression remission rates, controlling for age, sex, and body mass index. RESULTS: Of the 170 randomized participants (TCC: n = 85 and HEW: n = 85), 55 TCC and 58 HEW completed the 3-month assessment. The groups did not differ at baseline in any measure. At follow-up, neither the changes in cytokine/chemokines scores nor the depression remission rate differed significantly between TCC and HEW. However, remitters and non-remitters differed significantly in changes in a factor composed of growth-regulated oncogene protein-alpha (GRO-alpha), epidermal growth factor (EGF), and soluble CD40 ligand (sCD40L). GRO-alpha and EGF levels (in both groups) were significantly increased in remitters compared to non-remitters. CONCLUSION: Changes in certain cytokines/chemokines may accompany improvement in depressive symptoms in older adults. Future studies will need to explore the role of these molecules in remission of late-life depression.