Appreciating the links between heart failure and depression

Depression and heart failure frequently occur together, symptoms overlap and the prognosis is worsened. Both conditions share biopsychosocial risk factors and are accompanied by behavioural/lifestyle, neurohormonal, inflammatory and autonomic changes that are implicated aetiologically. Depression has been conceptualized as a decompensated response to allostatic overload, wherein adaptive psychological, behavioural and physiological responses to chronic and/or severe stress, become unsustainable. Heart failure can similarly be viewed as a decompensated response to circulatory overload, wherein adaptive functional (neurohormonal effects on circulation, inotropic effects on heart) and structural (myocardial remodelling) changes, become unsustainable. It has been argued that the disengaged state of depression can initially be protective, limiting an individual's exposure to external challenges, such that full recovery is often possible. In contrast, heart failure, once past a tipping-point, can progress relentlessly. Here, we consider the bidirectional interactions between depression and heart failure. Targeted treatment of depression in the context of heart failure may improve quality of life, yet overall benefits on mortality remain elusive. However, effective treatment of heart failure typically enhances function and improves key psychological and behavioural determinants of low mood. Prospectively, research that examines the mechanistic associations between depression and heart failure offers fresh opportunity to optimize personalized management in the advent of newer interventions for both conditions.