The impact of pre-morbid and post-morbid depression onset on mortality and cardiac morbidity among coronary heart disease patients: A meta-analysis.

Background: Depression is associated with increased cardiac morbidity and mortality in the general population and in coronary heart disease (CHD) patients. Recent evidence suggests that patients with new-onset depression post-CHD diagnosis have worse outcomes than those who had previous or recurrent depression. This meta-analysis investigated timing of depression onset in established CHD and CHD-free cohorts to determine what timeframe is associated with greater mortality and cardiac morbidity.

Methodology/Principal Findings: The MEDLINE, EMBASE, and PsycINFO databases were searched systematically to identify articles examining depression timeframe which specified an endpoint of all-cause mortality, cardiac mortality, re-hospitalization, or major adverse cardiac events (MACEs). A meta-analysis was conducted to estimate effect sizes by timeframe of depression. Twenty-two prospective cohort studies were identified. Nine studies investigated pre-morbid depression in CHD-free cohorts in relation to cardiac death. Thirteen studies in CHD-patient samples examined new-onset depression in comparison to previous or recurrent depression. The pooled effect size (risk ratio) was 0.76 (95% CI 0.48-1.19) for history of depression only, 1.79 (95% CI 1.45-2.21) for pre-morbid depression onset, 2.11 (95% CI 1.66-2.68) for post-morbid or new depression onset, and 1.59 (95% CI 1.08-2.34) for recurrent depression

Conclusions/Significance: Both pre-morbid and post-morbid depression onsets are potentially hazardous, and the question of timing may be irrelevant with respect to adverse cardiac outcomes. However, the combination of pre-morbid depression with the absence of depression at the time of a cardiac event (i.e., historical depression only) is not associated with such outcomes, and deserves further investigation.