For one, depression is tied to cardiovascular aging. In one study, men and women who had heart disease and depression had a 69 percent higher rate of death from heart disease than those who simply had heart disease and no depression. And in another study, depressed women were found to have lower bone density than those who weren't depressed, presumably from high levels of the stress hormone cortisol, which was found in higher levels in the blood of depressed people.
But perhaps the biggest factors are the indirect effects depression can have on aging. Depression leads to behaviors that accelerate the aging process. For example, depressed people are less likely to eat well, exercise, or take other actions to improve their health.
Find out more about this book:YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger