Cross-lagged analyses of the bidirectional relationship between depression and markers of chronic heart failure.

Experiencing depression and associated symptoms, such as lack of energy and fatigue, may lead to a further decrease of functional capacity, and consequently to a higher NYHA functional class in CHF patients. As NYHA functional class is associated with higher mortality, this may be a critical development for affected patients. Further studies are required to investigate whether or not this association could be an essential key that explains the pathway from depression to increased mortality in heart failure patients.