Depression, depressive symptoms and mortality in persons aged 65 and over living in the community: a systematic review of the literature

Background No recent attempt has been made to synthesize information on mor tality and depression despite the theoretical and practical interest in the topic. Our objective was to estimate in the older population the influence on mortality of depression and depressive symptoms. Methods Data sources were: Medline, Embase, personal files and colleagues' records. Studies were considered if they included a majority of persons age d greater than or equal to 65 years at baseline either drawn from a total c ommunity sample or drawn from a random sample from the community. Samples f rom healthcare facilities were excluded. Effect sizes were extracted from t he papers; if they were not included in the published papers, effect sizes were calculated if possible. No attempt was made to contact authors for mis sing data. Results We found 21 reports on 23 cohorts using depression diagnosis. For 1 5 of these, odds ratios were pooled using the Greenland method based on con fidence intervals (CIs), giving an estimated odds ratio for mortality with depression of 1.73 (95% CI 1.53 to 1.95). A fixed effects meta-regression o f these studies suggested that longer follow-up predicted smaller effect si zes (log odds ratios - 0.096 per year (95% CI - 0.179 to - 0.014)). There i s a weak suggestion of a reduced effect of depression on mortality for wome n. We were unable to pool effect sizes from the 17 studies using symptom to tals and scales, or from eight studies of specific symptoms. Conclusion The studies show that diagnosed depression in community-resident older people is associated with increased mortality. The picture for sex d ifferences is still unclear. Copyright (C) 2001 John Wiley & Sons, Ltd.