Objective: To examine the assumption that depression leads to recurrent cardiac events and death in those
with heart disease.
Methods: Consideration of alternative perspectives and discussion of the literature.
Results: It is not clear from studies like MIND-IT, ENRICHD or SADHART whether depression treatment improves
cardiac outcomes. In these studies, recurrent cardiac events and death were recorded 6 months or
more after study entry, but shorter-term cardiac outcomes (e.g., stabilization of plaque prone to rupture
and thrombosis or changes in areas of myocardium prone to life-threatening arrhythmia) were not assessed.
Although the prevailing view is that shorter-term improvement in depression is necessary to improve cardiovascular
outcomes, the possibility that shorter-term improvement in cardiac status might result in reduced
symptoms of depression has not been examined. If correct, this possibility might explain why studies have
shown that patients whose depression improves also exhibit improved cardiovascular outcomes and lower
mortality, even though randomization to the depression intervention in these studies had no effect.
Conclusion: It is not clear whether improving depression comes first and reduced cardiac events follows or
whether patients whose cardiac status improves also exhibit improvement in depression. Which is the chicken
and which the egg is more than just a philosophical question, since it may affect the direction of future
research in this field, and even how we approach the care of patients with heart disease and depression.