KNG1 and major depressive disorder: In addition, among the top ranked predictors were more objective features such as symptoms reported as being ‘observed by others’ concerning risky behaviour and speaking faster, the number of second-degree relatives with MDD, sleep disturbances, and several biomarkers including kininogen-1 (KNG1) and thrombospondin-1 (TSP1), proteins previously reported to discriminate BD from MDD43,44.