Explicating links between acute coronary syndrome and depression: Study design and methods

Objective: To describe a regional study seeking to replicate the suggested strong links whereby lifetime and post-coronary infarction depression are associated with a significant increase in mortality and cardiac morbidity, and consider the comparative influence of both depression and anxiety. Method: We detail relevant international studies and describe both the methodology as well as baseline and 1-month data from our study. Results: Over a 3-year period we recruited 489 subjects admitted to a Sydney cardiac unit with an Acute Coronary Syndrome (ACS), and assessed by a range of cardiac variables and measures of current and lifetime depression. Ninety-eight per cent of the sample were assessed one month after baseline recruitment to establish depression rates. Long-term outcome reviews of mortality and morbidity and hospitalization rates are proceeding. For those subjects who were depressed in the post-ACS period and, even more so for those who had experienced lifetime depression, distinctly higher scores on anxiety variables (and lifetime caseness for anxiety disorders) were established. Conclusions: The strong interdependence between anxiety and depression in this sample of patients admitted with an ACS will allow examination of the comparative extent to which expressions of 'depression' and 'anxiety' contribute to post-ACS morbidity.