Although this is the first study to examine the effect of hip fracture and depression on IL10 production by CD4+ T cells, a few studies examining the effect of chronic stress such as caregiving (Damjanovic et al. 2007; Glaser et al. 2001) and academic stress (Koh et al. 2008) have reported increased IL10 production and secretion. Here, CD4 is linked to depressive disorder.