Loneliness May Warp Our Genes, And Our Immune Systems - Loneliness takes a toll on many aspects of health, in part because it activates a fight-or-flight immune response. That may have helped ancestors survive lonely exile, but can slowly kill us today.
Infection and autoimmune activity result in inflammation. And psychiatric researchers now suspect that inflammation may play a role in some cases of depression and other mental illnesses. Katherine Streeter for NPR