A novel measure of inflammation in depression

Éimear Foley discusses a recent paper

Inflammation is thought to play a role in depression. According to research that combined information from many studies (i.e., systematic review and meta-analysis), approximately a quarter of all those diagnosed with depression also have consistently higher levels of inflammatory proteins, like C-reactive protein (CRP), in their blood. Large population-based studies and studies using genetic information (i.e., Mendelian Randomization) further suggest that inflammation, particularly an inflammatory protein called interleukin 6 (IL-6), play a key role in causing depression. (You can read more about the role of inflammation in depression in our IEUREKA blog on “Immune cells as biomarkers of depression”.) 

So far, studies examining this relationship between inflammation and depression have only focused on the levels of individual immune proteins in the blood, like IL-6 and CRP. At a cellular level, an inflammatory response is not caused by the activity of one inflammatory protein but rather by the interaction between several proteins working together to trigger a signalling response. Looking at the activity of proteins gives further insight into how these proteins relate to a particular condition, like depression. For this reason, in a recent study, we examined how IL-6 activity relates to symptoms and cognitive performance in people diagnosed with depression.   (more…)