Depressive symptoms are the strongest predictors of short-term declines in health status in patients with heart failure.
Rumsfeld JS, Havranek E, Masoudi FA, Peterson ED, Jones P, Tooley JF, Krumholz HM, Spertus JA. Depressive symptoms are the strongest predictors of short-term declines in health status in patients with heart failure. J Am Coll Cardiol. 2003 Nov 19; 42(10):1811-7.