Loneliness, it turns out, is as bad for your health as smoking, or being obese. The research that Prof. Cacioppo has done with colleagues also adds to the growing body of work that shows how bad loneliness can be for your health. It shows that loneliness suppresses the immune system and cardiovascular function, and increases the amount of stress hormone the body produces. It causes wear and tear on a cellular level, and impairs sleep. As he writes in his book Loneliness, "these changes in physiology are compounded in ways that may be hastening millions of people to an early grave."
Can anyone link to any research supporting these claims?