Difficulties in psychosocial functioning due to current depressive symptoms: What can C-Reactive protein tell us?

BACKGROUND: Multiple empirical studies and meta-analyses have examined how inflammation may be associated with various aspects of major depression, with older adults being particularly at risk for the effects of inflammation-related depression. Despite this wide area of research, no study has examined how depression-related inflammation impacts psychosocial functioning. METHODS: Data from the National Health and Nutrition Examination Survey, years 2007–2008, were utilized to examine whether adults over the age of 40 experienced difficulty in their work, taking care of things at home, or getting along with other people due to current depressive symptoms through a logistic regression analysis. We selected C-reactive protein (CRP), a common marker of immune system activation, as our primary predictor of interest while controlling for relevant covariates. RESULTS: Greater CRP was positively associated with a greater risk for individuals experiencing difficulties in psychosocial functioning due to depressive symptoms. While current number and severity of depressive symptoms was also found to be significant in the model, comparison of effect sizes identified that CRP appears to be a more relevant marker for experiencing difficulty than a number of relevant biopsychosocial covariates. CONCLUSION: Inflammation as measured by CRP may be a helpful tool in understanding how depressive symptoms are associated with an individual's ability to successfully navigate their social environment. Results here demonstrate the emerging utility of CRP in helping to assess the risk for negative outcomes in those experiencing depressive symptoms, especially as it pertains to older adults.